2,006 research outputs found
A Coupled Hybridizable Discontinuous Galerkin and Boundary Integral Method for Analyzing Electromagnetic Scattering
A coupled hybridizable discontinuous Galerkin (HDG) and boundary integral
(BI) method is proposed to efficiently analyze electromagnetic scattering from
inhomogeneous/composite objects. The coupling between the HDG and the BI
equations is realized using the numerical flux operating on the equivalent
current and the global unknown of the HDG. This approach yields sparse coupling
matrices upon discretization. Inclusion of the BI equation ensures that the
only error in enforcing the radiation conditions is the discretization.
However, the discretization of this equation yields a dense matrix, which
prohibits the use of a direct matrix solver on the overall coupled system as
often done with traditional HDG schemes. To overcome this bottleneck, a
"hybrid" method is developed. This method uses an iterative scheme to solve the
overall coupled system but within the matrix-vector multiplication subroutine
of the iterations, the inverse of the HDG matrix is efficiently accounted for
using a sparse direct matrix solver. The same subroutine also uses the
multilevel fast multipole algorithm to accelerate the multiplication of the
guess vector with the dense BI matrix. The numerical results demonstrate the
accuracy, the efficiency, and the applicability of the proposed HDG-BI solver
MicroRNA 506 regulates expression of PPAR alpha in hydroxycamptothecin-resistant human colon cancer cells
AbstractChemotherapeutic drug resistance remains a major obstacle to the successful treatment of colon cancer. Here, we show that 77 differentially expressed miRNAs were identified in SW1116/HCPT versus SW1116, and over-expressed miR-506 in SW1116/HCPT cells was validated. Then it was indicated that PPARα is a common target of miR-506 by using a luciferase reporter assay. Our results also demonstrated that cytotoxic ability of HCPT requires the concomitant presence of PPARα, and that loss of PPARα expression imparts resistance to HCPTs anti-tumor effects. All together, our studies indicate that miR-506 over-expression in established HCPT-resistant colon cancer cell line confers resistance to HCPT by inhibiting PPARα expression, then providing a rationale for the development of miRNA-based strategies for reversing resistance in HCPT-resistant colon cancer cells
Nanoscale polysaccharide derivative as an AEG-1 siRNA carrier for effective osteosarcoma therapy
Spin-glass ground state in a triangular-lattice compound YbZnGaO
We report on comprehensive results identifying the ground state of a
triangular-lattice structured YbZnGaO to be spin glass, including no
long-range magnetic order, prominent broad excitation continua, and absence of
magnetic thermal conductivity. More crucially, from the ultralow-temperature
a.c. susceptibility measurements, we unambiguously observe frequency-dependent
peaks around 0.1 K, indicating the spin-glass ground state. We suggest this
conclusion to hold also for its sister compound YbMgGaO, which is confirmed
by the observation of spin freezing at low temperatures. We consider disorder
and frustration to be the main driving force for the spin-glass phase.Comment: Version as accepted to PR
Evaluation of the mechanical properties and clinical application of nickel–titanium shape memory alloy anal fistula clip
ObjectiveThe study investigates the mechanical properties of a nickel–titanium shape memory alloy anal fistula clip (NiTi-AFC), studies the surgical method of treating anal fistula, and evaluates its clinical efficacy.MethodsThe anal fistula clip was formed in nickel–titanium alloy with a titanium content of 50.0%–51.8%. The mechanical properties and chemical properties were tested. A total of 31 patients with anal fistula were enrolled between 1 January 2020 and 1 January 2023. All patients underwent internal orifice closure surgery using NiTi-AFC, and anorectal magnetic resonance or ultrasound was performed before surgery and 6 months after surgery for diagnosis and evaluation. Fistula cure rates, length of stay, perianal pain, and Wexner incontinence scores were retrospectively compared between patients treated with NiTi-AFC and patients treated with other surgical methods.ResultNiTi-AFC has a density of 6.44–6.50 g·cm−3, with a shape-restoring force of 63.8 N. The corrosion rate of NiTi-AFC in 0.05% hydrochloric acid solution at atmospheric pressure and 20°C is approximately 6.8 × 10−5 g·(m·h)−1. A total of 31 patients (male/female: 19/12, age: 43.7 ± 17.8 years) were included. Among them, 22.6% (7) had multiple anal fistula, 16.1% (5) had high anal fistula, and 48.3% (15) had perianal fistula Crohn's disease. In total, 12.9% (4/31) did not achieve primary healing, underwent fistula resection, and eventually recovered. A retrospective analysis showed that the fistula healing rate, length of stay, and anal pain of NiTi-AFC treatment were similar to those of other traditional surgeries, but the Wexner incontinence score was significantly lower.ConclusionNiTi-AFC has shape memory properties, corrosion resistance, superelastic effect, and surface cell adhesion. It is applied to internal orifice closure surgery of anal fistula, with good therapeutic effect, and can protect the anal function
Renal mucinous tubular and spindle cell carcinoma: a report of 8 cases and review of the literature
- …