Organic Functionalization of Mesoporous Silica Spheres as a Nanovehicle for DOX pH-Triggered Delivery

Shuai Wang,Fang Xiang Song,Li Zhang,Xue Zhang,Yan Li 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.8

Mesoporous silica (MS) spheres of different sizes with pH-responsive characteristics were synthesized based on Stöber's theory. Organic functionalization with aminopropyl and carboxyl groups resulted in different materials, namely, MS@NH2@COOH. MS@NH2@COOH were observed to have a large number of carboxyl groups and multiamine chains, and were grafted into pore channels and pore outlets through systematic characterization analyses. All modified samples demonstrated the controlling of the delivery rate of DOX from the siliceous matrix. We also compared the drug release behavior of the DOX-loaded materials at high pH (7.4) and low pH (5.5) and studied the cytotoxicity on A549 cells. The experimental results indicated that the drug delivery system can better control drug release and have potential applications in the drug delivery field.

Cryptosporidium spp., Giardia intestinalis, and Enterocytozoon bieneusi in Captive Non-Human Primates in Qinling Mountains

Shuai-Zhi Du,Guang-Hui Zhao,Jun-Feng Shao,Yan-Qin Fang,Ge-Ru Tian,Long-Xian Zhang,Rong-Jun Wang,Hai-Yan Wang,Meng Qi,San-Ke Yu 대한기생충학열대의학회 2015 The Korean Journal of Parasitology Vol.53 No.4

Certain Polymorphisms in SP110 Gene Confer Susceptibility to Tuberculosis: A Comprehensive Review and Updated Meta-Analysis

Shuai Zhang,Fang Zheng,Xue-bin Wang,Ya-di Han,Chen Wang,Ye Zhou 연세대학교의과대학 2017 Yonsei medical journal Vol.58 No.1

Purpose: Numerous studies have assessed the association of SP110 gene variants with tuberculosis (TB), but the results were inconsistent. Through a comprehensive review and meta-analysis, our study aimed to clarify the nature of genetic risks contributedby 11 polymorphisms for the development of TB. Materials and Methods: Through searching PubMed, web of science, China National Knowledge Infrastructure (CNKI) databases,a total of 11 articles including 13 independent studies were selected. The pooled odd ratios (ORs) along with their corresponding95% confidence interval (CI) were estimated for allelic comparisons, additive model (homozygote comparisons; heterozygotecomparisons), dominant model and recessive model. We also assessed the heterogeneity across the studies and publication bias. Results: The results of combined analysis revealed a significantly increased risk of TB for single nucleotide polymorphism (SNP)rs9061 in all five comparisons (allelic comparisons: OR=1.28, 95% CI=1.14–1.44, p<0.0001; homozygote comparisons: OR=2.84, 95%CI=1.84–4.38, p<0.00001; heterozygote comparisons: OR=1.23, 95% CI=1.05–1.43, p=0.009; dominant model: OR=1.32, 95% CI=1.14–1.53, p=0.0003; recessive model: OR=2.26, 95% CI=1.18–4.34, p=0.01). In subgroup analysis, the risk of TB associated with SNP rs9061appeared to be increased. Moreover, increased risk of TB was also found in Asian subgroup of SNP rs11556887, while decreased riskof TB appeared in large sample size subgroup of SNP rs1135791. No significant association was observed between other SNPs andthe risk of TB. Conclusion: Our meta-analysis suggested that the variant of SNP rs9061 might be a risk factor for TB.

Experimental Study on the Mechanical Behaviour of Natural Loess Based on Suction-Controlled True Triaxial Tests

Fang Zheng,Shengjun Shao,Jiao Wang,Shuai Shao 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.8

Loess is mostly distributed in an unsaturated state in nature, and the complexity of the engineering properties of unsaturated soil is mainly due to the existence of matric suction. Therefore, matric suction must be considered in investigating the mechanical properties of unsaturated loess. However, soils are most often subjected to three principal stresses with different magnitudes in practical engineering. For the sake of examining and discussing the mechanical behaviour of unsaturated natural loess under a complex stress path, a suction-controlled true triaxial apparatus with a rigid-flexible boundary is used to test unsaturated natural loess under a complicated stress path. Four trials of isotropic consolidation tests are conducted on natural loess under suction-controlled conditions via the true triaxial apparatus. The consolidation yield characteristics of the natural loess under different matric suctions are investigated. Forty-eight trials of consolidated drained true triaxial tests under suction-controlled conditions are conducted on unsaturated natural loess to examine and discuss the influence of the matric suction and intermediate principal stress parameter (b-value). The consolidated drained trials are performed under a constant net mean stress and a constant matric suction with different intermediate principal stress parameters (b-values). Stress-strain curves and failure envelopes of the natural loess are also presented. The results indicate that the stress-strain-strength response of unsaturated natural loess depends on the matric suction and intermediate principal stress parameter under true triaxial conditions.

Dynamic characteristics analysis of partial-interaction composite continuous beams

Genshen Fang,Jingquan Wang,Shuai Li,Shubin Zhang 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.21 No.1

The dynamic characteristics of continuous steel-concrete composite beams considering the effect of interlayer slip were investigated based on Euler Bernoulli's beam theory. A simplified calculation model was presented, in which the Mode Stiffness Matrix (MSM) was developed. The natural frequencies and modes of partialinteraction composite continuous beams can be calculated accurately and easily by the use of MSM. Proceeding from the present method, the natural frequencies of two-span steel-concrete composite continuous beams with different span-ratios (0.53, 0.73, 0.85, 1) and different shear connection stiffnesses on the interface are calculated. The influence pattern of interfacial stiffness on bending vibration frequency was found. With the decrease of shear connection stiffness on the interface, the flexural vibration frequencies decrease obviously. And the influence on low order modes is more obvious while the reduction degree of high order is more sizeable. The real natural frequencies of partial-interaction continuous beams commonly used could have a 20% to 40% reduction compared with the fully-interaction ones. Furthermore, the reduction-ratios of natural frequencies for different span-ratios two-span composite beams with uniform shear connection stiffnesses are totally the same. The span-ratio mainly impacts on the mode shape. Four kinds of shear connection stiffnesses of steel-concrete composite continuous beams are calculated and compared with the experimental data and the FEM results. The calculated results using the proposed method agree well with the experimental and FEM ones on the low order modes which mainly determine the vibration properties.

Bending characteristics of corroded reinforced concrete beam under repeated loading

Congqi Fang,Shuai Yang,Zhang Zhang 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.47 No.6

Bending behaviors of corroded reinforced concrete (RC) beams under repeated loading were investigated experimentally. A total of twenty test specimens, including four non-corrosion and sixteen corrosion reinforced concrete beams, were prepared and tested. A numerical model for flexural and cracking behaviors of the beam under repeated loading was also developed. Effects of steel corrosion on reinforced concrete beams regarding cracking, mid-span deflection, stiffness and bearing capacity of corroded beams were studied. The impact of corrosion on bond strength as the key factor was investigated to develop the computational model of flexural capacity. It was shown from the experimental results that the bond strength between reinforcement and concrete had increased for specimen of low corrosion levels, while this effect was changed when the corrosion level was higher. It was indicated that the bearing capacity of corrosion beam increased even at a corrosion level of about 5%.

Identification of Chinese green tea (Camellia sinensis) marker metabolites using GC/MS and UPLC-QTOF/MS

Yu-shuai Wang,Min-zhe Fang,Sheng-dao Zheng,조진경,이태후 한국식품과학회 2021 Food Science and Biotechnology Vol.30 No.10

Tea is one of the most widely consumed aromaticbeverages in the world because of its taste and flavor,as well as due to many potential health beneficial properties. Metabolomics focuses on an in-depth analysis of allmetabolites in living organisms. In this study, 29 primarymetabolites and 25 secondary metabolites were identifiedusing GC/MS and UPLC-QTOF/MS, respectively. Further,PCA analysis showed conspicuous discrimination for theten varieties of green tea with metabolite profiling. Amongthem, organic acids, amino acids, flavan-3-ols, and flavonolglycosides varied greatly through checking the VIP valuesof the PLS-DA model. Moreover, the intrinsic and/orextrinsic factors characterizing each type of green tea werealso discussed. The chemical component marker derivedhere should be used as an important detection index, whileevaluating the tea quality, as well as while establishing thetea quality standard.

MODELING AND CONTROL OF A HIGH SPEED ON/OFF VALVE ACTUATOR

Jigen Fang,Xifeng Wang,Jinjun Wu,Shuai Yang,Liang Li,Xiang Gao,Yue Tian 한국자동차공학회 2019 International journal of automotive technology Vol.20 No.6

Accurate electromagnetic force control in a high speed on/off valve actuator (HSVA) can improve the performance of a vehicle braking system, and an accurate theoretical model is the key to smoothly controlling the high speed on/off valve. Therefore, a nonlinear model of an HSVA is proposed in this paper. Three subsystems are modeled as a spring/ mass/damper system, a nonlinear resistor/inductor system and a multiwall heat transfer system, respectively. Then, a slidingmodel controller combined with a sliding-model observer is designed to adjust the electromagnetic force for an accurate HSVA state control, taking the effect of the coil heating into account. The feasibility of the three submodels and the slidingmodel controller are verified by comparing the simulation results with the experimental results obtained on a test bench. Our study shows that the three subsystems are coupled to one another through resistance, displacement, and temperature. When the excitation voltage exceeds 9 V, the coil temperature can reach more than 150 degrees Celsius within 300 s, and the electromagnetic force decreases by approximately 30 %. However, by applying the above control strategy, the electromagnetic force can also be stable, fluctuating within 5 % even if the temperature of the coil rises to the thermal equilibrium temperature.

Preparation and properties of Nd-doped BCTH lead-free ceramics by solid-phase twin crystal method

He Xiyue,Fang Bijun,Zhang Shuai,Lu Xiaolong,Ding Jianning 한국물리학회 2022 Current Applied Physics Vol.38 No.-

0.5 mol% Nd-doped (Ba0.85Ca0.15)(Ti0.9Hf0.1)O3 (BCTH-Nd) lead-free ceramics were prepared by a solid-phase twin crystal method, where the effects of sintering condition on structure, electrical and optical properties were studied. All the sintered BCTH-Nd ceramics exhibit pure perovskite structure, dense microstructure with several micron grain size, which tends to increase with elevating sintering temperature. All synthesized ceramics have complex dielectric behavior, which presents normal ferroelectrics characteristic with slight dispersion phenomenon. The BCTH-Nd ceramics exhibit excellent piezoelectric and ferroelectric properties and acceptable dielectric performance when sintered at 1480 ◦C for 2 h. Under 269 nm light excitation, several fluorescent emission peaks are excited with a whole indigo fluorescence, where the strongest emission peak is emitted at 473 nm, corresponding to the 4G3/2 → 4I9/2 energy level transition of Nd3+. Multifunctional performance is fulfilled in the lead-free BCTH ceramics via rare earth doping, which can broaden the application fields of piezoelectricbased materials.

Study on the Vehicle-Induced LTAS Law of the Tunnel in Diatomite Area

Huijian Zhang,Shuai Zhang,Wei Fang,Gongning Liu,Wenshan Gao,Zuoyang Jiang,Kai Liu 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.4

Due to the weak characteristics of diatomite, excessive settlement may happen under long-term dynamic vibration load and affect the later operation of trains, while there are few researches on the dynamic response of highway tunnel in diatomite yet. Taking the Feifengshan high-speed railway tunnel project as the study case, the impact of different reinforcement parameters on long-term accumulated settlement (LTAS) rule of the highway tunnel in the diatomite area under train load is studied by numerical simulation and layer-wise summation method (LWSM). The results reveal that tunnel LTAS in diatomite area mainly appears in the first and the second years of the running stage of train, and the LTAS in these two years accounts for half of the ultimate stable LTAS. The longer the pile length (PL) and the larger the pile diameter (PD), the smaller the dynamic deviatoric stress (DDS) and LTAS. However, when pile lengths or pile diameter exceed a certain range (PL = 16 m or the PD = 150 mm), the control effect of increasing the PL and PD on the LTAS of the tunnel in diatomite is no longer significant. This indicates that there exist preferred values of the PL and PD. There are few cases of the construction of highway tunnels in the diatomite area before the engineering project in this paper yet. Hence, this paper will provide a reference to the construction of the foundation reinforcement scheme of high-speed railway tunnels in diatomite layer.