Formulation of nimodipine nanocrystals for oral administration

Jianwen Li,Qiang Fu,Xiaohong Liu,Mo Li,Yongjun Wang 대한약학회 2016 Archives of Pharmacal Research Vol.39 No.2

The aim of this paper is to optimize nimodipine (NMD) nanocrystals (NCs) for oral administration. The effects of independent process variables (microprecipitation temperature, shearing speed, shearing time, homogenization pressure and number of cycles) on the particle size have been studied. Experiments were conducted to optimize the formulation composition. A single factor exploration was used to screen the primary stabilizers. Then, the selected polymers/surfactants were further optimized using an L9 (34) orthogonal design. The optimal formulation was composed of NMD (0.7 %, w/v), F127 (0.4 %, w/v), HPMC-E5 (0.1 %, w/v), and sodium deoxycholate (0.05 %, w/v) and was rod-shaped as shown by SEM observations, and it had a particle size of 833.3 ± 20.6 nm, determined by laser diffraction. These aqueous NCs were physically stable for 15 days. To further improve the stability, the NCs were freeze-dried. The powder obtained exhibited acceptable flowability and was physically stable for at least 24 months. Additionally, the NMD NCs displayed much higher dissolution profiles than the bulk drug. The pharmacokinetic results showed that the relative bioavailability was 397 % in comparison with Nimotop, suggesting that NCs are an efficient strategy for improving the oral bioavailability of poorly water-soluble drugs.

Characterization of the first tuber mustard calmodulin-like gene, BjAAR1, and its functions in responses to abiotic stress and abscisic acid in Arabidopsis

Liuxin Xiang,Yuxian Xia,Ying-Fan Cai,Jijun Liu,Xiaohong He,Quan Sun,Xiaoyan Wang,Yuyin Fu,Yonghong Fan,Daiwen Dong,Guanfan Zhou,Jinjuan Shen,Yihua Liu 한국식물학회 2013 Journal of Plant Biology Vol.56 No.3

The first tuber mustard calmodulin-like (CML) gene BjAAR1 (Brassica juncea var. tumida Tsen et Lee Abiotic stress and Abscisic acid (ABA) Responsive gene 1) was cloned and characterized. The protein encoded by BjAAR1 contains four predicted Ca2+ binding sites (EF-hand motif) and its recombinant protein can bind Ca2+ in vitro. qRT-PCR showed that the expression level of BjAAR1 was rather high in non-swollen stem of tuber mustard and largely reduced in swollen stem. Expression of BjAAR1 enhanced ABA- and stress-induced gene expression in Arabidopsis (Arabidopsis thaliana). Transgenic plants also exhibited hypersensitivity to NaCl, mannitol, and ABA during the seed germination and post-germination stages. ABA biosynthesis inhibitor, norflurazon (NF), rescued hypersensitivity phenotype of transgenic plants to NaCl and mannitol, indicating that BjAAR1 functions in multiple abiotic stresses response through ABA-dependent process.

Inverse Analysis of Inconel 718 Laser-Assisted Milling to Achieve Machined Surface Roughness

Yixuan Feng,Tsung-Pin Hung,Yu-Ting Lu,Yu-Fu Lin,Fu-Chuan Hsu,Chiu-Feng Lin,Ying-Cheng Lu,Xiaohong Lu,Steven Y. Liang 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.11

This manuscript proposes an inverse analysis method for the machined surface roughness in laser-assisted milling on Inconel 718. The method solves the forward problem considering the tool profile and the elastic recovery of machined surface and applies the variance-based recursive method to guide the updating mechanism of process parameters to match the measurements. Subsequently, the inverse analysis identifies four process parameters of feed per tooth, tool tip radius, minimum cutting thickness, and tool tip angle, and finds the optimal solution for target performance, the surface roughness. The measurements are collected under the single beam coaxial laser-assisted milling spindle. The proposed modified Kalman filter algorithm introduces the gain coefficient G when updating the process parameters to improve robustness and accuracy. The inverse analysis is conducted on all measurements, and the average error of target performance is 0.460% when the laser is on and 0.394% when the laser is off. The average difference of process parameters is less than 5%, and the selection process is done in 50 loops within a minute. Therefore, the proposed inverse analysis model is robust, adaptive to different initial guesses and measurements, highly accurate, and saves computation time.

DFT study of the adsorption of 2, 3, 7, 8-tetrachlorodibenzofuran (TCDF) on vacancy-defected graphene doped with Mn and Fe

Qingxiao Zhou,Yongliang Yong,Weiwei Ju,Xiangying Su,Xiaohong Li,Chaoyang Wang,Zhibing Fu 한국물리학회 2018 Current Applied Physics Vol.18 No.1

Dioxins are highly toxic to humans and environment, and developing the effective methods to control and detect the organic pollutant is particular important. Here we performed a density functional theory (DFT) study on the adsorption of 2, 3, 7, 8-tetrachlorodibenzofuran (TCDF) molecules on the modified graphene substrates. The results indicated that the introducing of vacancy-defect and dopants (Mn and Fe) significantly improves the sensitivity toward TCDF molecules. The impurity played a crucial role for interacting with TCDF molecules. Furthermore, the adsorption of TCDF induced band-gap open in defected graphene substrates, which could be seen as electric signal to detect TCDF pollutant. The present study is expected to be useful to explore effective materials to detect and remove dioxin pollutants based on graphene.

Numerical Investigation on the Design and Optimization of Stacking Pattern for High Flexural Performance Carbon Fiber Reinforced Resin Matrix Composites

Yao Cai,Xizhong An,Qingchuan Zou,Dengzhi Yao,Haitao Fu,Hao Zhang,Xiaohong Yang 한국섬유공학회 2022 Fibers and polymers Vol.23 No.9

The stacking sequences of fiber-reinforced composites for optimization of turbine blades with the bestperformance have become a focus of attention. However, the optimization and design principles of its flexural performanceare not yet mature. Referring to the problems in previous work, a 3D finite element flexural model of carbon fiber reinforcedcomposites was established based on the Abaqus/Explicit VUMAT subroutine through the Tsai-Wu failure criterion. Theinfluencing laws and optimization mechanisms of different stacking patterns (e.g., different orientations, number oforientation plies, combination of multiple orientation plies, and symmetry/asymmetry structures) on the flexural properties ofthe composites were systematically investigated, and corresponding design references for the optimization of stackingpatterns were given. The results show that the smaller the value of |θ-45 °| (θ represents the angle of the orientation ply), themore obvious the stress reduction of the orientation ply, and the orientation ply located in the outer layer is more conducive tothe improvement of flexural performance. As the number of orientation plies increases, the flexural strength anddisplacement increase, but the stability decreases, in which the laminate with 50 % 0 ° orientation plies has the best overallperformance. In addition, the stability ranking of the laminate stacking sequences for the same 0 ° orientation ply proportionis: multi-orientation asymmetric > multi-orientation symmetric > single-orientation symmetric. In particular, the [75/02/60/30/02/15] laminate has the best overall performance with the flexural strength of 974 MPa and the Y-axis offset of 0.057 mm,and its stability is 66 % higher than that of the [15/02/75]S laminate. Under the same tensile/compressive stresses, the actualstress of the warp/weft in the orientation ply is less than the maximum ideal stress and the stress of Y-axis direction SY ≠ 0,which delays the fracture of the orientation ply and causes displacement offset, and the increase of the number of orientationplies will aggravate this effect. The obtained highlighted results can provide valuable references for the design andoptimization of stacking patterns of plain fabric-reinforced laminates with high flexural properties.

Postoperative circulating tumor DNA detection and CBLB mutations are prognostic biomarkers for gastric cancer

Zhou Hekai,Liu Houcong,Li Jun,Wang Jidong,Fu Xiaohong,Li Yingqiang,Mao Shaolong,Du Jihui 한국유전학회 2023 Genes & Genomics Vol.45 No.8

Background Several studies have demonstrated that circulating tumor DNA (ctDNA) can be used to predict the postoperative recurrence of several cancers. However, there are few studies on the use of ctDNA as a prognosis tool for gastric cancer (GC) patients. Objective This study aims to determine whether ctDNA could be used as a prognostic biomarker in GC patients through multigene-panel sequencing. Methods Using next-generation sequencing (NGS) Multigene Panels, the mutational signatures associated with the prognosis of GC patients were identified. We calculated the survival probability with Kaplan–Meier and used the Log-rank test to compare survival curves between ctDNA-positive and ctDNA-negative groups. Potential application of radiology combined with tumor plasma biomarker analysis of ctDNA in GC patients was carried out. Results Disease progression is more likely in ctDNA-positive patients as characterized clinically by a generally higher T stage and a poorer therapeutic response (P < 0.05). ctDNA-positive patients also had worse overall-survival (OS: P = 0.203) and progression-free survival (PFS: P = 0.037). The combined analysis of ctDNA, radiological, and serum biomarkers in four patients indicated that ctDNA monitoring can be a good complement to radiological and plasma tumor markers for GC patients. Kaplan–Meier analysis using a cohort of GC patients in the TCGA database showed that patients with CBLB mutations had shorter OS and PFS than wild-type patients (OS: P = 0.0036; PFS: P = 0.0027). Conclusions This study confirmed the utility and feasibility of ctDNA in the prognosis monitoring of gastric cancer.