1,338 research outputs found
The Effects of Magnetic Field Strength on Properties of Wind Generated from Hot Accretion Flow
Observations indicate that wind can be generated in hot accretion flow. By
performing numerical simulations, Yuan et al. studied the detailed properties
of wind generated from weakly magnetized accretion flow. However, properties of
wind generated from strongly magnetized hot accretion flow have not been
studied. In this paper, we study the properties of wind generated from both
weakly and strongly magnetized accretion flow. We focus on how the magnetic
field strength affects the wind properties. We solve time-steady
two-dimensional magnetohydrodynamic (MHD) equations of black hole accretion in
the presence of large-scale magnetic field. We assume self-similarity in radial
direction. The magnetic field is assumed to be evenly symmetric with the
equatorial plane. We find that wind exists in both weakly and strongly
magnetized accretion flow. When magnetic field is weak (magnetic pressure is
more than 2 orders of magnitude smaller than gas pressure), wind is driven by
gas pressure gradient and centrifugal forces. When magnetic field is strong
(magnetic pressure is slightly smaller than gas pressure), wind is driven by
gas pressure gradient and magnetic pressure gradient forces. The power of wind
in strongly magnetized case is just slightly larger than that in weakly
magnetized case. The power of wind lies in a range , with and being mass inflow
rate and speed of light, respectively. The possible role of wind in active
galactic nuclei feedback is briefly discussed.Comment: 8 pages, 4 figures, accepted by A&
Numerical Simulation of Hot Accretion Flow around Bondi Radius
Previous numerical simulations have shown that strong winds can be produced
in the hot accretion flows around black holes. Most of those studies focus only
on the region close to the central black hole, therefore it is unclear whether
the wind production stops at large radii around Bondi radius. Bu et al. 2016
studied the hot accretion flow around the Bondi radius in the presence of
nuclear star gravity. They find that when the nuclear stars gravity is
important/comparable to the black hole gravity, winds can not be produced
around the Bondi radius. However, for some galaxies, the nuclear stars gravity
around Bondi radius may not be strong. In this case, whether winds can be
produced around Bondi radius is not clear. We study the hot accretion flow
around Bondi radius with and without thermal conduction by performing
hydrodynamical simulations. We use the virtual particles trajectory method to
study whether winds exist based on the simulation data. Our numerical results
show that in the absence of nuclear stars gravity, winds can be produced around
Bondi radius, which causes the mass inflow rate decreasing inwards. We confirm
the results of Yuan et al. which indicates this is due to the mass loss of gas
via wind rather convectional motions.Comment: 15 pages, 8 figures, accepted for publication in Ap
Parathyroid Adenoma Presenting as a Brown Tumour of the Mandible
Background. Parathyroid adenoma is the commonest cause of primary hypercalcaemia and usually presents with symptoms/signs of hypercalcaemia. This paper highlights an unusual presentation. Case Report. A 27-year-old female presented with a painful left mandibular swelling, suspicious of neoplasia. A computed tomography (CT) guided biopsy was performed. Based on the histology result, serum calcium was carried out, confirming hypercalcaemia. A left inferior parathyroid adenoma was subsequently removed. CT mandible showed extensive erosive lesions at the left 2nd/3rd inferior molar roots with protrusion to adjacent soft tissues. USS revealed a hypoechoic lesion on the left inferior parathyroid gland. Sestamibi scan showed a focus of MIBI uptake and retention at the inferior aspect of the left thyroid lobe. Conclusion. This case highlights the importance of a thorough history and examination. Clinicians should always bear in mind atypical presentations of parathyroid adenomas, with the need to exclude this differential in the presence of hypercalcaemia
A molecular neuromorphic network device consisting of single-walled carbon nanotubes complexed with polyoxometalate
In contrast to AI hardware, neuromorphic hardware is based on neuroscience, wherein constructing both spiking neurons and their dense and complex networks is essential to obtain intelligent abilities. However, the integration density of present neuromorphic devices is much less than that of human brains. In this report, we present molecular neuromorphic devices, composed of a dynamic and extremely dense network of single-walled carbon nanotubes (SWNTs) complexed with polyoxometalate (POM). We show experimentally that the SWNT/POM network generates spontaneous spikes and noise. We propose electron-cascading models of the network consisting of heterogeneous molecular junctions that yields results in good agreement with the experimental results. Rudimentary learning ability of the network is illustrated by introducing reservoir computing, which utilises spiking dynamics and a certain degree of network complexity. These results indicate the possibility that complex functional networks can be constructed using molecular devices, and contribute to the development of neuromorphic devices
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First-in-Man Phase I Trial of the Selective MET Inhibitor Tepotinib in Patients with Advanced Solid Tumors.
PurposeTepotinib is an oral, potent, highly selective MET inhibitor. This first-in-man phase I trial investigated the MTD of tepotinib to determine the recommended phase II dose (RP2D).Patients and methodsPatients received tepotinib orally according to one of three dose escalation regimens (R) on a 21-day cycle: R1, 30-400 mg once daily for 14 days; R2, 30-315 mg once daily 3 times/week; or R3, 300-1,400 mg once daily. After two cycles, treatment could continue in patients with stable disease until disease progression or unacceptable toxicity. The primary endpoint was incidence of dose-limiting toxicity (DLT) and treatment-emergent adverse events (TEAE). Secondary endpoints included safety, tolerability, pharmacokinetics, pharmacodynamics, and antitumor effects.ResultsOne hundred and forty-nine patients received tepotinib (R1: n = 42; R2: n = 45; R3: n = 62). Although six patients reported DLTs [one patient in R1 (115 mg), three patients in R2 (60, 100, 130 mg), two patients in R3 (1,000, 1,400 mg)], the MTD was not reached at the highest tested dose of 1,400 mg daily. The RP2D of tepotinib was established as 500 mg once daily, supported by translational modeling data as sufficient to achieve ≥95% MET inhibition in ≥90% of patients. Treatment-related TEAEs were mostly grade 1 or 2 fatigue, peripheral edema, decreased appetite, nausea, vomiting, and lipase increase. The best overall response in R3 was partial response in two patients, both with MET overexpression.ConclusionsTepotinib was well tolerated with clinical activity in MET-dysregulated tumors. The RP2D of tepotinib was established as 500 mg once daily. MET abnormalities can drive tumorigenesis. This first-in-man trial demonstrated that the potent, highly selective MET inhibitor tepotinib can reduce or stabilize tumor burden and is well tolerated at doses up to 1,400 mg once daily. An RP2D of 500 mg once daily, as determined from translational modeling and simulation integrating human population pharmacokinetic and pharmacodynamic data in tumor biopsies, is being used in ongoing clinical trials
Lower 30-day readmission rates with roflumilast treatment among patients hospitalized for chronic obstructive pulmonary disease
BACKGROUND: Few data exist related to the impact of roflumilast on health care utilization. This retrospective study estimated 30-day hospital readmission rates between patients who did and did not use roflumilast among those with COPD hospitalizations. METHODS: Data were from MarketScan, a large US commercial health insurance claims database. Patients aged ≥40 years with at least one hospitalization for COPD between 2010 and 2011 were included. The roflumilast group included patients who used roflumilast within 14 days after the first hospitalization (index), while the comparison group (non-roflumilast) included patients who did not use roflumilast during the study period. Continuous enrollment for at least 6 months before and 30 days after the index date was required. The 30-day hospitalization rate was calculated after the index hospitalization. Conditional logistic regression with propensity score 1:3 matching was employed to assess the difference in 30-day hospital readmission rates between the roflumilast and non-roflumilast groups, adjusting for baseline characteristics, comorbidity, health care utilization, and COPD medication use within 14 days after the index date. RESULTS: A total of 15,755 COPD patients met the selection criteria, ie, 366 (2.3%) in the roflumilast group and 15,389 (97.7%) in the non-roflumilast group. The mean (± standard deviation) age was 71±12.5 years and 52% were female. After propensity score matching, all-cause 30-day hospitalization rates were 6.9% and 11.1% in the roflumilast and non-roflumilast groups, respectively. COPD-related 30-day hospitalization rates were 6.3% and 9.2% in the roflumilast and non-roflumilast groups, respectively. Conditional logistic regression identified a significantly lower likelihood of all-cause 30-day readmission (odds ratio 0.59, 95% confidence interval 0.37–0.93, P=0.023) for roflumilast patients relative to non-roflumilast patients. CONCLUSION: This study showed, in a real-world setting, that use of roflumilast was associated with a lower rate of hospital readmission within 30 days among patients hospitalized for COPD
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