331 research outputs found
Implicit-correction-based immersed boundary-lattice Boltzmann method with two relaxation times
In the present paper, we verify the effectiveness of the two-relaxation-time (TRT) collision operator in reducing boundary slip computed by the immersed boundary-lattice Boltzmann method (IB-LBM). In the linear collision operator of the TRT, we decompose the distribution function into symmetric and antisymmetric components and define the relaxation parameters for each part.The Chapman-Enskog expansion indicates that one relaxation time for the symmetric component is related to the kinematic viscosity. Rigorous analysis of the symmetric shear flows reveals that the relaxation time for the antisymmetric part controls the velocity gradient, the boundary velocity, and the boundary slip velocity computed by the IB-LBM. Simulation of the symmetric shear flows, the symmetric Poiseuille flows, and the cylindrical Couette flows indicates that the profiles of the numerical velocity calculated by the TRT collision operator under the IB-LBM framework exactly agree with those of the multi-relaxation time (MRT). The TRT is as effective in removingthe boundary slip as the MRT. We demonstrate analytically and numerically that the error of the boundary velocity is caused by the smoothing technique using the delta function used in the interpolation method. In the simulation of the flow past a circular cylinder, the IB-LBM based on the implicit correction method with the TRT succeeds in preventing the flow penetration through the solid surface as well as unphysical velocity distortion. The drag coefficient, the wake length, and the separation points calculated by the present IB-LBM agree well with previous studies at Re =10, 20, and 40
Development of 1,3a,6a-triazapentalene-labeled enterobactin as a fluorescence quenching sensor of iron ion
1,3a,6a-Triazapentalene (TAP)-labeled enterobactin was developed as an iron ion sensor. 3-Acetylated-TAP was successfully introduced to the catechol ring of enterobactin, a well-recognized siderophore secreted by various Gram-negative bacteria. The fluorescence of TAPlabeled enterobactin decreased gradually as the amount of Fe3+ ion as an additive was increased, and 1.2 equiv of Fe3+ ion completely quenched the fluorescence. In clear contrast, when other metal ions were used, the fluorescence of TAP-labeled enterobactin remained even at 5.0 equiv
IMMERSED BOUNDARY-FINITE DIFFERENCE LATTICE BOLTZMANN METHOD USING TWO RELAXATION TIMES
ABSTRACT It is known that velocity fields computed by using an immersed boundary-lattice Boltzmann method (IB-LBM) with a single-relaxation time (SRT) show unphysical distortion when the relaxation time, Ï„, is high. The authors proposed an immersed boundary-finite difference lattice Boltzmann method (IB-FDLBM) using SRT to predict liquid-solid flows. In simulations with IB-FDLBM, numerical errors in the velocity fields appear as in IBLBMs when Ï„ is high. A two-relaxation time (TRT) collision operator is therefore implemented into IB-FDLBM in this study to reduce numerical errors at high Ï„. Simulations of circular Couette flows show that the proposed method gives accurate predictions at high Ï„, provided that the magic parameter, which is a function of the relaxation times, is less than unity. In addition, predicted drag coefficients of a circular cylinder and a sphere at low Reynolds numbers show reasonable agreements with theoretical solutions and measured data
The Combination of Gemcitabine, Cisplatin, and Paclitaxel as Salvage Chemotherapy for Advanced Urothelial Carcinoma
There is no standard second-line or salvage treatment for advanced urothelial carcinoma (UC). Here we investigated the efficacy and safety of gemcitabine, cisplatin, and paclitaxel (GCP) combination chemotherapy as salvage chemotherapy for advanced UC. We retrospectively analyzed the cases of 23 patients with advanced UC who showed progression or recurrence after cisplatin-based chemotherapy. Gemcitabine (1000 mg/m2), and paclitaxel (80 mg/m2) were administered on days 1 and 8. Cisplatin (70 mg/m2) was administered on day 1. The 3-week cycle regimen was repeated until disease progression if it had no intolerable toxicity. The overall response rate was 61% (95%CI, 41-78%). The median overall survival and progression-free survival times were 14 months and 5.5 months, respectively. Of the already known risk factors of chemotherapy for advanced UC, only the performance status was a prognostic factor for OS. Overall, 16 of the 23 patients (70%) experienced grade 3/4 toxicities, and no fatal adverse events were observed. GCP therapy was a promising option as second-line or salvage therapy for advanced UC
Behavior of snow monkeys hunting fish to survive winter
Japanese macaques, Macaca fuscata, of Kamikochi in the Japanese Alps endure one of the coldest and harshest environments during winter when scarcity of food puts them at risk. However, various behaviors have evolved to mitigate potential mortality. These macaques typically eat bamboo leaves and the bark of woody plants in winter, but our previous study using the feces of Japanese macaques collected in the winter and DNA metabarcoding analysis revealed conclusively for the first time consumption of riverine benthos and brown trout. In this paper, we investigate how Japanese macaques hunt fish and collect these riverine biota by extensively observing their behavior, including the use of infrared sensor cameras. Many researchers have tracked Japanese macaques as part of behavioral and ecological studies, but previously the techniques by which Japanese macaques capture swimming fish has not been documented. Herein, for the first time we consider how novel macaque foraging behavior traits have evolved to secure valuable animal protein for winter survival when food resources are scarce
Design of engineered active zymogen of microbial transglutaminase
Please click Additional Files below to see the full abstrac
A new therapeutic strategy with istradefylline for postural deformities in Parkinson’s disease
Aim of the study. Postural deformities are common in Parkinson’s disease (PD) patients. Several treatment options have been reported, but responses to these treatments appear unpredictable. Istradefylline is a novel drug for PD. Cases of PD patients whose postural deformities were improved after withdrawal of dopamine agonists and initiation of istradefylline are presented. Materials and Methods. Four consecutive patients with postural deformities including antecollis, Pisa syndrome, and camptocormia were recruited and treated with istradefylline in combination with withdrawal of dopamine agonists, which are possible causes of postural deformities. Results. The dopamine agonists were discontinued an average of 26 months after the development of the postural deformities, and istradefylline was initiated an average of 1.3 months after dopamine agonist withdrawal. Three patients with preserved paraspinal muscle volume showed good responses to the treatment regimen at least two months after dopamine agonist withdrawal. Conclusions and clinical Implications. Postural deformities caused by dopamine agonists generally improve less than two weeks after dopamine agonist withdrawal. Given the response time in the present study, the response was unlikely to be caused solely by dopamine agonist withdrawal. Istradefylline can be a potential therapeutic option; however, appropriate selection of patients for treatment with istradefylline is warranted
Synthesis and characterization of conductive flexible cellulose carbon nanohorn sheets for human tissue applications
Background
Conductive sheets of cellulose and carbon nanomaterials and its human skin applications are an interesting research aspect as they have potential for applications for skin compatibility. Hence it is needed to explore the effects and shed light on these applications.
Method
To fabricate wearable, portable, flexible, lightweight, inexpensive, and biocompatible composite materials, carbon nanohorns (CNHs) and hydroxyethylcellulose (HEC) were used as precursors to prepare CNH-HEC (Cnh-cel) composite sheets. Cnh-cel sheets were prepared with different loading concentrations of CNHs (10, 20 50,100mg) in 200mg cellulose. To fabricate the bio-compatible sheets, a pristine composite of CNHs and HEC was prepared without any pretreatment of the materials.
Results
The obtained sheets possess a conductivity of 1.83x10(-10)S/m and bio-compatible with human skin. Analysis for skin-compatibility was performed for Cnh-cel sheets by h-CLAT in vitro skin sensitization tests to evaluate the activation of THP-1 cells. It was found that THP-1 cells were not activated by Cnh-cel; hence Cnh-cel is a safe biomaterial for human skin. It was also found that the composite allowed only a maximum loading of 100mg to retain the consistent geometry of free-standing sheets of m thickness. Since CNHs have a unique arrangement of aggregates (dahlia structure), the composite is homogeneous, as verified by transmission electron microscopy (TEM) and, scanning electron microscopy (SEM), and other functional properties investigated by Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), conductivity measurement, tensile strength measurement, and skin sensitization.
Conclusion
It can be concluded that cellulose and CNHs sheets are conductive and compatible to human skin applications
- …