912 research outputs found

    Quantization of virtual Grothendieck rings and their structure including quantum cluster algebras

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    The quantum Grothendieck ring of a certain category of finite-dimensional modules over a quantum loop algebra associated with a complex finite-dimensional simple Lie algebra g\mathfrak{g} has a quantum cluster algebra structure of skew-symmetric type. Partly motivated by a search of a ring corresponding to a quantum cluster algebra of {\em skew-symmetrizable} type, the quantum {\em virtual} Grothendieck ring, denoted by Kq(g)\mathfrak{K}_q(\mathfrak{g}), is recently introduced by Kashiwara--Oh \cite{KO23} as a subring of the quantum torus based on the (q,t)(q,t)-Cartan matrix specialized at q=1q=1. In this paper, we prove that Kq(g)\mathfrak{K}_q(\mathfrak{g}) indeed has a quantum cluster algebra structure of skew-symmetrizable type. This task essentially involves constructing distinguished bases of Kq(g)\mathfrak{K}_q(\mathfrak{g}) that will be used to make cluster variables and generalizing the quantum TT-system associated with Kirillov--Reshetikhin modules to establish a quantum exchange relation of cluster variables. Furthermore, these distinguished bases naturally fit into the paradigm of Kazhdan--Lusztig theory and our study of these bases leads to some conjectures on quantum positivity and qq-commutativity

    Initial serum sodium concentration determines the decrease in sodium level after terlipressin administration in patients with liver cirrhosis

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    BACKGROUND: Terlipressin, as a prodrug of vasopressin, has agonistic effects on the V1 receptor and partial agonistic effects on renal vasopressin V2 receptors. However, its effects on serum sodium concentration are controversial. METHODS: This study retrospectively investigated 127 patients with liver cirrhosis to examine the incidence and risk factors for the decrease in serum sodium level following terlipressin administration. RESULTS: Terlipressin was prescribed for bleeding control (99) and management of hepatorenal syndrome (28). Serum sodium level decreased from 134.0 ± 6.5 mmol/L to 130.4 ± 6.2 mmol/L during or after terlipressin treatment (P < 0.001) in all patients. In 45 patients (35.4%), the serum sodium concentration decreased by > 5 mmol/L, in 29 patients (22.8%); by 5–10 mmol/L; and in 16 patients (12.6%), by > 10 mmol/L. Five patients in the latter group showed neurological manifestations. In the univariate analysis, several factors including age, purpose of use, serum creatinine, and Model for End-Stage Liver Disease score, representing liver function, were significantly associated with the decrease in serum sodium after terlipressin administration. However, a multivariate analysis revealed that only initial sodium level was the most powerful predictor of terlipressin-induced reduction in serum sodium. CONCLUSION: An acute reduction in serum sodium concentration was not uncommon during terlipressin treatment, and the baseline serum sodium level was closely related to the reduction in serum sodium concentration

    Molecular Subgroup Analysis of Clinical Outcomes in a Phase 3 Study of Gemcitabine and Oxaliplatin with or without Erlotinib in Advanced Biliary Tract Cancer

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    AbstractBACKGROUND: We previously reported that the addition of erlotinib to gemcitabine and oxaliplatin (GEMOX) resulted in greater antitumor activity and might be a treatment option for patients with biliary tract cancers (BTCs). Molecular subgroup analysis of treatment outcomes in patients who had specimens available for analysis was undertaken. METHODS: Epidermal growth factor receptor (EGFR), KRAS, and PIK3CA mutations were evaluated using peptide nucleic acid–locked nucleic acid polymerase chain reaction clamp reactions. Survival and response rates (RRs) were analyzed according to the mutational status. Sixty-four patients (48.1%) were available for mutational analysis in the chemotherapy alone group and 61 (45.1%) in the chemotherapy plus erlotinib group. RESULTS: 1.6% (2/116) harbored an EGFR mutation (2 patients; exon 20), 9.6% (12/121) harbored a KRAS mutation (12 patients; exon 2), and 9.6% (12/118) harbored a PIK3CA mutation (10 patients, exon 9 and 2 patients, exon 20). The addition of erlotinib to GEMOX in patients with KRAS wild-type disease (n = 109) resulted in significant improvements in overall response compared with GEMOX alone (30.2% vs 12.5%, P = .024). In 95 patients with both wild-type KRAS and PIK3CA, there was evidence of a benefit associated with the addition of erlotinib to GEMOX with respect to RR as compared with GEMOX alone (P = .04). CONCLUSION: This study demonstrates that KRAS mutational status might be considered a predictive biomarker for the response to erlotinib in BTCs. Additionally, the mutation status of PIK3CA may be a determinant for adding erlotinib to chemotherapy in KRAS wild-type BTCs

    Primary Synovial Sarcoma of the Thyroid Gland

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    Synovial sarcoma is a rare but distinct soft tissue neoplasm, most commonly occurring in para-articular regions of the extremities of young adults and also occurring in the head and neck region. To the best of our knowledge, only one case of primary synovial sarcoma of the thyroid has been previously reported. Here, we report a 15-yr-old man who had a chief complaint of a palpable neck mass. The neck computed tomography revealed a relatively well-demarcated solid mass in the left thyroid gland. After fine needle aspiration cytology, total thyroidectomy and lymph node dissection were performed. Grossly, the mass was covered by the same capsule as the thyroid gland, measuring 6×5×5 cm in dimensions and weighing 78 gm. The cut surface showed a well demarcated, lobulated, grayish tan, and rubbery solid tumor. Histologically, this tumor was a biphasic synovial sarcoma. Immunohistochemical, ultrastructural, genetic studies, and cytologic findings were all consistent with synovial sarcoma. When synovial sarcomas arise in this unusual site, recognition and differential diagnosis become more difficult. The differential diagnosis of a spindle epithelial tumor with thymus-like differentiation is very difficult due to their similar clinical, histological, and immunohistochemical features. Ultrastructural and cytogenetic studies for synovial sarcoma are necessary to establish a definitive diagnosis

    Risk factors for transmission in a COVID-19 cluster infection in a high school in the Republic of Korea

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    Objectives This study aimed to examine the scale, characteristics, risk factors, and modes of transmission in a coronavirus disease 2019 (COVID-19) outbreak at a high school in Seoul, Republic of Korea. Methods An epidemiological survey was conducted of 1,118 confirmed cases and close contacts from a COVID-19 outbreak at an educational facility starting on May 31, 2021. In-depth interviews, online questionnaires, flow evaluations, and CCTV analyses were used to devise infection prevention measures. Behavioral and spatial risk factors were identified, and statistical significance was tested. Results Among 3rd-year students, there were 33 confirmed COVID-19 cases (9.6%). Students who used a study room in the annex building showed a statistically significant 4.3-fold elevation in their relative risk for infection compared to those who did not use the study room. Moreover, CCTV facial recognition analysis confirmed that 17.8% of 3rd-year students did not wear masks and had the lowest percentage of mask-wearers by grade. The air epidemiological survey conducted in the study room in the annex, which met the 3 criteria for a closed space, confirmed that there was only 10% natural ventilation due to the poor ventilation system. Conclusion To prevent and manage the spread of COVID-19 in educational facilities, advance measures that consider the size, operation, and resources of each school are crucial. In addition, various survey methodologies should be used in future studies to quickly analyze a wider range of data that can inform an evidence-based quarantine response
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