19 research outputs found

    Granular cell tumor of the esophagus in an adolescent

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    Esophageal granular cell tumor (GCT) is a rare neoplasm originating from the Schwann cells of the submucosal neuronal plexus. Histology is the gold standard for its diagnosis. Endoscopic resection or surgical excision should be considered, depending on the potential for malignancy. Here, we report a case of an esophageal GCT in an adolescent. A 12-year-old boy presented with a 1-year history of dysphagia and vomiting. Upper gastrointestinal endoscopic examination and esophagography showed narrowing of the midesophagus, and computed tomography angiography of the thoracic aorta revealed an esophageal or periesophageal mass posterior to the paratracheal segment of the esophagus. The tumor was surgically excised, and based on the pathological findings, esophageal GCT was diagnosed

    The U.S.–South Korean Alliance: Anti-American Challenges

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    Atomistic insights into adhesion characteristics of tungsten on titanium nitride using steered molecular dynamics with machine learning interatomic potential

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    Abstract As transistor integration accelerates and miniaturization progresses, improving the interfacial adhesion characteristics of complex metal interconnect has become a major issue in ensuring semiconductor device reliability. Therefore, it is becoming increasingly important to interpret the adhesive properties of metal interconnects at the atomic level, predict their adhesive strength and failure mode, and develop computational methods that can be universally applied regardless of interface properties. In this study, we propose a method for theoretically understanding adhesion characteristics through steering molecular dynamics simulations based on machine learning interatomic potentials. We utilized this method to investigate the adhesion characteristics of tungsten deposited on titanium nitride barrier metal (W/TiN) as a representative metal interconnect structure in devices. Pulling tests that pull two materials apart and sliding tests that pull them against each other in a shear direction were implemented to investigate the failure mode and adhesive strength depending on TiN facet orientation. We found that the W/TiN interface showed an adhesive failure where they separate from each other when tested with pulling force on Ti-rich (111) or (001) facets while cohesive failures occurred where W itself was destroyed on N-rich (111) facet. The adhesion strength was defined as the maximum force causing failure during the pulling test for consistent interpretation and the strengths of tungsten were predicted to be strongest when deposited onto N-rich (111) facet while weakest on Ti-rich (111) facet

    Treatment outcomes in metastatic and localized high-grade salivary gland cancer: high chance of cure with surgery and post-operative radiation in T1–2 N0 high-grade salivary gland cancer

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    Abstract Background High-grade salivary gland cancer is a distinct clinical entity that has aggressive disease progression and early systemic spread. However, because of the rarity of the disease, the clinical outcomes, prognostic factors and clinical decision on the optimal treatments have not been fully understood. Methods In this study, we retrospectively analyzed the clinical data of 124 patients with high-grade salivary gland cancers and performed multivariate survival analyses to evaluate the clinico-pathological factors affecting the treatment outcomes. Results The 5-year disease-specific survival was 63.4% in patients with high-grade salivary gland cancers. Among the clinico-pathological factors, presence of lymph node metastasis (hazard ratio 5.63, 95% confidence interval 2.64–12.03, P < 0.001) and distant metastasis (hazard ratio 4.59, 95% confidence interval 2.10–10.04, P < 0.001) at diagnosis were the most potent unfavorable prognostic factors. Importantly, patients with early-stage disease (T1–2N0M0) showed apparently a relatively excellent prognosis (93.2% 5-year disease-specific survival); meanwhile N (+) and M1 status at diagnosis resulted in dismal outcomes (44.6 and 21.1% 5-year disease-specific survival, respectively). On comparing surgery alone as a treatment modality, surgery plus postoperative radiation significantly benefited the patients, but the difference between adjuvant radiation and chemoradiation was not found to be significant. Pathological subtypes of high-grade salivary gland cancers were not significantly associated with prognosis. Conclusions Despite of an overall unfavorable prognosis in high-grade salivary gland cancer, patients with early-stage disease are expected to have excellent prognosis (over 90% survival rates) with surgery plus adjuvant radiation, which may implicate the patients’ consultation, therapeutic decision making, and the need for early detection of the disease

    Kohn-Sham Time-Dependent Density Functional Theory on the Massively Parallel Graphics Processing Units

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    We report a high-performance multi graphics processing unit (GPU) implementation of the Kohn-Sham time-dependent density functional theory (TDDFT) within the Tamm-Dancoff approximation. Our newly developed GPU algorithm on massively parallel computing systems using multiple parallel models in tandem scales optimally with material size, considerably reducing the computational wall time. A benchmark TDDFT study was performed on a green fluorescent protein complex composed of 4,353 atoms with 40,518 atomic orbitals represented by Gaussian-type functions. As the largest molecule attempted to date to the best of our knowledge, the proposed strategy demonstrated reasonably high efficiencies up to 256 GPUs on a custom-built state-of-the-art GPU computing system with Nvidia A100 GPUs. We believe that our GPU-oriented algorithms, which empower first-principles simulation for very large-scale applications, may render deeper understanding of the molecular basis of material behaviors, eventually revealing new possibilities for breakthrough designs on new material systems

    Three-State-Involving Vibronic Resonance Is a Key to Enhancing Reverse Intersystem Crossing Dynamics of Organoboron-Based Ultrapure Blue Emitters

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    In organoboron OLED emitter DABNA, vibronic resonance strongly enhances reverse intersystem crossing rate even with a sizable T1-S1 energy gap. The resonance is peculiar in that the vibrational frequency has to match both (1) the T1-S1 energy gap and (2) the T1-T3 nonadiabatic coupling oscillation frequency. This three-state involving resonance is a result of combination of T1-T3-S1 superexchange and T1-T3 non-Condon coupling.<br /
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