914 research outputs found

    Competing states for the fractional quantum Hall effect in the 1/3-filled second Landau level

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    In this work, we investigate the nature of the fractional quantum Hall state in the 1/3-filled second Landau level (SLL) at filling factor ν=7/3\nu=7/3 (and 8/3 in the presence of the particle-hole symmetry) via exact diagonalization in both torus and spherical geometries. Specifically, we compute the overlap between the exact 7/3 ground state and various competing states including (i) the Laughlin state, (ii) the fermionic Haffnian state, (iii) the antisymmetrized product state of two composite fermion seas at 1/6 filling, and (iv) the particle-hole (PH) conjugate of the Z4Z_4 parafermion state. All these trial states are constructed according to a guiding principle called the bilayer mapping approach, where a trial state is obtained as the antisymmetrized projection of a bilayer quantum Hall state with interlayer distance dd as a variational parameter. Under the proper understanding of the ground-state degeneracy in the torus geometry, the Z4Z_4 parafermion state can be obtained as the antisymmetrized projection of the Halperin (330) state. Similarly, it is proved in this work that the fermionic Haffnian state can be obtained as the antisymmetrized projection of the Halperin (551) state. It is shown that, while extremely accurate at sufficiently large positive Haldane pseudopotential variation δV1(1)\delta V_1^{(1)}, the Laughlin state loses its overlap with the exact 7/3 ground state significantly at δV1(1)0\delta V_1^{(1)} \simeq 0. At slightly negative δV1(1)\delta V_1^{(1)}, it is shown that the PH-conjugated Z4Z_4 parafermion state has a substantial overlap with the exact 7/3 ground state, which is the highest among the above four trial states.Comment: 22 pages, 5 figure

    Characteristics and treatments of large cystic brain metastasis: radiosurgery and stereotactic aspiration.

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    Brain metastasis represents one of the most common causes of intracranial tumors in adults, and the incidence of brain metastasis continues to rise due to the increasing survival of cancer patients. Yet, the development of cystic brain metastasis remains a relatively rare occurrence. In this review, we describe the characteristics of cystic brain metastasis and evaluate the combined use of stereotactic aspiration and radiosurgery in treating large cystic brain metastasis. The results of several studies show that stereotactic radiosurgery produces comparable local tumor control and survival rates as other surgery protocols. When the size of the tumor interferes with radiosurgery, stereotactic aspiration of the metastasis should be considered to reduce the target volume as well as decreasing the chance of radiation induced necrosis and providing symptomatic relief from mass effect. The combined use of stereotactic aspiration and radiosurgery has strong implications in improving patient outcomes

    One-Round Protocol for Two-Party Verifier-Based Password-Authenticated Key Exchange

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    Abstract. Password-authenticated key exchange (PAKE) for two-party allows a client and a server communicating over a public network to share a session key using a human-memorable password only. PAKE protocols can be served as basic building blocks for constructing secure, complex, and higher-level protocols which were initially built upon the Transport Layer Security (TLS) protocol. In this paper, we propose a provablysecure verifier-based PAKE protocol well suited with the TLS protocol which requires only a single round. The protocol is secure against attacks using compromised server's password file and known-key attacks, and provides forward secrecy, which is analyzed in the ideal hash model. This scheme matches the most efficient verifier-based PAKE protocol among those found in the literature. It is the first provably-secure one-round protocol for verifier-based PAKE in the two-party setting

    Catalytic pyrolysis of Laminaria japonica over nanoporous catalysts using Py-GC/MS

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    The catalytic pyrolysis of Laminaria japonica was carried out over a hierarchical meso-MFI zeolite (Meso-MFI) and nanoporous Al-MCM-48 using pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). The effect of the catalyst type on the product distribution and chemical composition of the bio-oil was examined using Py-GC/MS. The Meso-MFI exhibited a higher activity in deoxygenation and aromatization during the catalytic pyrolysis of L. japonica. Meanwhile, the catalytic activity of Al-MCM-48 was lower than that of Meso-MFI due to its weak acidity

    The Clinical Features and Risk Factors of Subglottic Cysts in Children: A Clinical Experience Using the Spontaneous Respiration Technique

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    Objectives Subglottic cysts (SGCs) are a rare cause of respiratory distress resulting from upper airway obstruction in infants and young children. Risk factors other than prematurity with a history of endotracheal intubation have not yet been well elucidated. Therefore, we aimed to describe the clinical features and analyze the risk factors of SGCs. Methods We conducted a retrospective review of medical records of pediatric patients who underwent marsupialization for SGCs between January 2017 and March 2022. These records were then compared with those of controls with a history of neonatal intubation, with a case-to-control ratio of 1:3. Results Eleven patients (eight boys and three girls) diagnosed with SGCs and 33 control patients (26 boys and seven girls) were included. All patients had a history of premature birth and neonatal intubation. Symptoms of SGCs appeared at a mean age of 8.2 months (range, 1–14 months) after extubation. The mean duration of intubation was 21.5 days (range, 2–90 days), and the intubation period was longer in patients with SGCs than in controls (21.5±24.8 days vs. 5.3±7.1 days; P<0.001). Furthermore, gestational age (28.3±4.2 weeks vs. 33.8±4.4 weeks; P=0.001) and birth weight (1,134.1±515.1 g vs. 2,178.2±910.1 g; P=0.001) were significantly lower in patients with SGCs than in controls. Multivariable analysis identified the intubation period as an independent risk factor. Conclusion This study showed that gestational age, birth weight, and the intubation period were significantly associated with the development of SGCs. Pediatric patients presenting with progressive dyspnea who have the corresponding risk factors should undergo early laryngoscopy for the differential diagnosis of SGC

    Novel next generation sequencing panel method for the multiple detection and identification of foodborne pathogens in agricultural wastewater

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    Detecting and identifying the origins of foodborne pathogen outbreaks is a challenging. The Next-Generation Sequencing (NGS) panel method offers a potential solution by enabling efficient screening and identification of various bacteria in one reaction. In this study, new NGS panel primer sets that target 18 specific virulence factor genes from six target pathogens (Bacillus cereus, Yersinia enterocolitica, Staphylococcus aureus, Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus) were developed and optimized. The primer sets were validated for specificity and selectivity through singleplex PCR, confirming the expected amplicon size. Crosscheck and multiplex PCR showed no interference in the primer set or pathogenic DNA mixture. The NGS panel analysis of spiked water samples detected all 18 target genes in a single reaction, with pathogen concentrations ranging from 108 to 105 colony-forming units (CFUs) per target pathogen. Notably, the total sequence read counts from the virulence factor genes showed a positive association with the CFUs per target pathogen. However, the method exhibited relatively low sensitivity and occasional false positive results at low pathogen concentrations of 105 CFUs. To validate the detection and identification results, two sets of quantitative real-time PCR (qPCR) analyses were independently performed on the same spiked water samples, yielding almost the same efficiency and specificity compared to the NGS panel analysis. Comparative statistical analysis and Spearman correlation analysis further supported the similarity of the results by showing a negative association between the NGS panel sequence read counts and qPCR cycle threshold (Ct) values. To enhance NGS panel analysis for better detection, optimization of primer sets and real-time NGS sequencing technology are essential. Nonetheless, this study provides valuable insights into applying NGS panel analysis for multiple foodborne pathogen detection, emphasizing its potential in ensuring food safety

    Nuclear Factor Erythroid-Derived 2-Like 2-Induced Reductive Stress Favors Self-Renewal of Breast Cancer Stem-Like Cells via the FoxO3a-Bmi-1 Axis

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    Aims: A subpopulation of cancer cells, termed cancer stem cells (CSCs), has stemness properties, such as self-renewal and differentiation, which drive cancer recurrence and tumor resistance. CSCs possess enhanced protection capabilities to maintain reduced intracellular levels of reactive oxygen species (ROS) compared with nonstem-like cancer cells. This study investigated whether reductive stress could regulate self-renewal activity in breast CSCs. Results: We found that manifestation of stemness in breast cancer stem-like cells was associated with an elevated production of reduced glutathione (GSH) maintained by upregulation of glutamate cysteine ligase catalytic subunit (GCLC) and consequently, lowered ROS levels. This was accompanied by upregulation of phospho-AMP-activated protein kinase, FoxO3a, and Bmi-1. Notably, expression of nuclear factor erythroid-derived 2-like 2 (Nrf2) protein was substantially increased in cells undergoing sphere formation. We noticed that expression of Bmi-1 was inhibited after introduction of Nrf2 short interfering RNA into MCF-7 mammosphere cells. Silencing of Nrf2 expression suppressed the xenograft growth of subcutaneously or orthotopically injected human breast cancer cells. Innovation: Association between Nrf2 and self-renewal signaling in CSCs has been reported, but the underlying molecular mechanism remains largely unresolved. This study demonstrates the Nrf2-mediated signaling pathway in maintenance of reductive stress in breast CSCs. Conclusion: Nrf2 overactivation in breast CSCs upregulates GCLC expression and consequently enhances GSH biosynthesis with concurrent reduction in intracellular ROS accumulation, thereby provoking the reductive stress. The consequent upregulation of nuclear FoxO3a and its binding to the promoter of the gene encoding Bmi-1 account for the self-renewal activity of breast cancer stem-like cells and their growth in a xenograft mouse model.
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