Study on the Kinetic Characteristics of Microbubbles in Cross-Shaped Flow Focusing Microchannels

Ding Weibing,Yang Qianwen,Zhao Yaohui,Wang Zhaohui,Chen Jie,Wang Hongxia 한국화학공학회 2024 Korean Journal of Chemical Engineering Vol.41 No.1

To study the mechanism of microbubbles generation in cross-shaped microchannels, numerical simulations of gas–liquid two-phase fl ow in microchannels are carried out in this paper using the volume of fl uid method (VOF). By varying the twophase fl ow rate, three diff erent fl ow regimes were obtained, including dripping regime, slugging regime and threading regime, and the relationship between the two-phase fl ow rate and the fl ow state was plotted. Meanwhile, the phase interface, pressure and velocity of microbubbles in three diff erent fl ow regimes were studied, and the evolution of the gas–liquid interface in microbubbles formation was analyzed. It is found that the microbubbles diameter decreases and the frequency increases as the viscosity of the continuous phase gradually increases. As the wall contact angle decreases, the adhesion of the liquid phase to the wall at the channel interaction increases and the microbubbles diameter increases. The increase in interfacial tension greatly increases the cohesion between molecules on the surface of the gas fl ow, making it diffi cult to achieve force equilibrium, which leads to a reduction in the shear stress required to dominate the interface to break the tip of the gas fl ow and slower bubbles formation, resulting in a larger microbubbles diameter.

VJM: A Novel Grid Resource Co-Allocation Model for Parallel Jobs

Xiaohui WEI,Zhaohui DING,Shaocheng XING,Yaoguang YUAN 보안공학연구지원센터(IJGDC) 2009 International Journal of Grid and Distributed Comp Vol.2 No.1

The synergy effect of arbuscular mycorrhizal fungi symbiosis and exogenous calcium on bacterial community composition and growth performance of peanut (Arachis hypogaea L.) in saline alkali soil

Ci Dunwei,Tang Zhaohui,Ding Hong,Cui Li,Zhang Guanchu,Li Shangxia,Dai Liangxiang,Qin Feifei,Zhang Zhimeng,Yang Jishun,Xu Yang 한국미생물학회 2021 The journal of microbiology Vol.59 No.1

Peanut (Arachis hypogaea. L) is an important oil seed crop. Both arbuscular mycorrhizal fungi (AMF) symbiosis and calcium (Ca2+) application can ameliorate the impact of saline soil on peanut production, and the rhizosphere bacterial communities are also closely correlated with peanut salt tolerance; however, whether AMF and Ca2+ can withstand high-salinity through or partially through modulating rhizosphere bacterial communities is unclear. Here, we used the rhizosphere bacterial DNA from saline alkali soil treated with AMF and Ca2+ alone or together to perform high-throughput sequencing of 16S rRNA genes. Taxonomic analysis revealed that AMF and Ca2+ treatment increased the abundance of Proteobacteria and Firmicutes at the phylum level. The nitrogenfixing bacterium Sphingomonas was the dominant genus in these soils at the genus level, and the soil invertase and urease activities were also increased after AMF and Ca2+ treatment, implying that AMF and Ca2+ effectively improved the living environment of plants under salt stress. Moreover, AMF combined with Ca2+ was better than AMF or Ca2+ alone at altering the bacterial structure and improving peanut growth in saline alkali soil. Together, AMF and Ca2+ applications are conducive to peanut salt adaption by regulating the bacterial community in saline alkali soil.

Intelligent Biodegradable Polymeric Nanocarriers for Cancer Therapeutics

Xuesi Chen,Jianxun Ding,Zhaohui Tang 한국고분자학회 2013 한국고분자학회 학술대회 연구논문 초록집 Vol.2013 No.10

Antibody-conjugated gold nanoparticles as nanotransducers for second near-infrared photo-stimulation of neurons in rats

Liu Jiansheng,Li Jiajia,Zhang Shu,Ding Mengbin,Yu Ningyue,Li Jingchao,Wang Xiuhui,Li Zhaohui 나노기술연구협의회 2022 Nano Convergence Vol.9 No.13

Infrared neural stimulation with the assistance of photothermal transducers holds great promise as a mini-invasive neural modulation modality. Optical nanoparticles with the absorption in the near-infrared (NIR) window have emerged as excellent photothermal transducers due to their good biocompatibility, surface modifiability, and tunable optical absorption. However, poor activation efficiency and limited stimulation depth are main predicaments encountered in the neural stimulation mediated by these nanoparticles. In this study, we prepared a targeted polydopamine (PDA)-coated gold (Au) nanoparticles with specific binding to thermo-sensitive ion channel as nanotransducers for second near-infrared (NIR-II) photo-stimulation of neurons in rats. The targeted Au nanoparticles were constructed via conjugation of anti-TRPV1 antibody with PEGylated PDA-coated Au nanoparticles and thus exhibited potent photothermal performance property in the second NIR (NIR-II) window and converted NIR-II light to heat to rapidly activate Ca 2+ influx of neurons in vitro. Furthermore, wireless photothermal stimulation of neurons in living rat successfully evoke excitation in neurons in the targeted brain region as deep as 5 mm beneath cortex. This study thus demonstrates a remote-controlled strategy for neuromodulation using photothermal nanotransducers.

Application of Brodmann’s Area Maps for Cortical Localization of Tactile Perception Evoked by Fabric Touch

Qicai Wang,Yuan Tao,Jie Yuan,Zhaohui Jiang,Zuowei Ding,Zhongwei Zhang,Zhao Jia,Jing Wang 한국섬유공학회 2019 Fibers and polymers Vol.20 No.4

Different sensations are generated when we touch textiles with different performance. The mechanical propertiesrelated to fabric touch have been studied for a long time, the relationship between which and the subjective feelings is wellunderstood. However, the cognitive mechanism of our brain on the tactile perception evoked by fabric touch were rarelystudied. The relationship between mechanical properties of fabrics and the brain response in different areas is the vacancy ofthe study but urgent problem. In our previous study, the advanced technology of fMRI was proved to be an effective tool fordetecting brain response evoked by tactile stimulation of fabric touch with high spatial resolution. Now in this study, furtherfMRI experiments were conducted to observe brain response when participants touched different fabrics using their fingers ina specified way, and the most widely recognized functional atlas, Brodmann’s area maps, were applied to locate the corticalactivations in functional areas. Activations in the participants’s brain in different Brodmann areas was compared with themechanical preperties of the fabric samples tested by the instruments of KES-FB. The results showed that activationinformation in the participants’ brain can distinguish the fabric samples very well. Activations in several Brodmann areas areclosely connected with different tactile preperties of the fabrics. Therefore, Brodmann’s area maps were proved to be a usefulfunctional atlas for cortical localization of tactile perception evoked by fabric touch.

Preparation and Self-Healing Behaviors of Poly(acrylic acid)/Cerium Ions Double Network Hydrogels

Hongwei Zhou,Guohe Xu,Jie Li,Shihao Zeng,Xiaolong Zhang,Zhaohui Zheng,Xiaobin Ding,Weixing Chen,Qiguan Wang,Wenzhi Zhang 한국고분자학회 2015 Macromolecular Research Vol.23 No.12

This work aims at developing an approach to poly(acrylic acid)/cerium ions (PAA/cerium ions) double network hydrogels and exploring the self-healing properties of the hydrogels, with expectation to provide some clues for constructing new healable gel actuators and enrich the family of self-healable hydrogels. The hydrogel is covalently crosslinked by a traditional crosslinking agent N,N'-methylene bis-acrylamide to form the first network and further physically crosslinked by the ionic interaction between cerium ions and the carboxyl groups in the hydrogel network. The preparation method and self-healing behaviors of the hydrogels are investigated.

A BIO-INSPIRED POLYDOPAMINE APPROACH TO PREPARATION OF GOLD-COATED Fe3O4 CORE-SHELL NANOPARTICLES: SYNTHESIS, CHARACTERIZATION AND MECHANISM

PENG AN,FANG ZUO,XINHUA LI,YUANPENG WU,JUNHUA ZHANG,ZHAOHUI ZHENG,XIAOBIN DING,YUXING PENG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2013 NANO Vol.8 No.6

A biomimetic and facile approach for integrating Fe3O4 and Au with polydopamine (PDA) was proposed to construct gold-coated Fe3O4 nanoparticles (Fe3O4@Au–PDA) with a core–shell structure by coupling in situ reduction with a seed-mediated method in aqueous solution at room temperature. The morphology, structure and composition of the core–shell structured Fe3O4@Au–PDA nanoparticles were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and X-ray photoelectron spectrometry (XPS). The formation process of Au shell was assessed using a UV-Vis spectrophotometer. More importantly, according to investigating changes in PDA molecules by Fourier transform infrared spectroscopy (FTIR) and in preparation process of the zeta-potential data of nanoparticles, the mechanism of core–shell structure formation was proposed. Firstly, PDA-coated Fe3O4 are obtained using dopamine (DA) self-polymerization to form thin and surface-adherent PDA films onto the surface of a Fe3O4 "core". Then, Au seeds are attached on the surface of PDA-coated Fe3O4 via electrostatic interaction in order to serve as nucleation centers catalyzing the reduction of Au3+ to Au0 by the catechol groups in PDA. Accompanied by the deposition of Au, PDA films transfer from the surface of Fe3O4 to that of Au as stabilizing agent. In order to confirm the reasonableness of this mechanism, two verification experiments were conducted. The presence of PDA on the surface of Fe3O4@Au–PDA nanoparticles was confirmed by the finding that glycine or ethylenediamine could be grafted onto Fe3O4@Au–PDA nanoparticles through Schiff base reaction. In addition, Fe3O4@Au–DA nanoparticles, in which DA was substituted for PDA, were prepared using the same method as that for Fe3O4@Au–PDA nanoparticles and characterized by UV-Vis, TEM and FTIR. The results validated that DA possesses multiple functions of attaching Au seeds as well as acting as both reductant and stabilizing agent, the same functions as those of PDA.

Transcriptional profiling analysis of OsDT11-mediated ABA-dependent signal pathway for drought tolerance in rice

Zhao Man,Ju Yanhu,Zhao Bo,Li Xiaoming,Dai LIli,Qu Jicheng,Chu Zhaohui,Ding Xinhua 한국식물생명공학회 2020 Plant biotechnology reports Vol.14 No.5

Small cysteine-rich peptides (CRPs) are important in plant responses to biotic and abiotic stresses. OsDT11, encoding an 88 amino acid CRP-type protein, has been reported to enhance tolerance to drought in rice (Oryza sativa L.) without negatively afecting other agronomic traits. However, the molecular mechanisms of OsDT11-mediated drought tolerance are still unclear. Here, we performed RNA-Seq analysis to compare the transcriptome profles between wild-type (WT) and OsDT11-overexpressing (OE) rice lines under drought stress or under control (non-drought) conditions. A total of 1570 and 1421 diferentially expressed genes were identifed in the OE lines and the WT under drought treatment, respectively, compared to non-drought conditions. Gene ontology analysis indicated that the 430 up-regulated genes in common to both OE and the WT lines were induced for functions related to responses to water deprivation and to abscisic acid (ABA). More than half of these genes had higher expression in the OE than in the WT under drought stress. In the OE, but not in the WT, 294 genes were specifcally up-regulated under drought stress and were functionally enriched in starch and sucrose biosyn�thetic processes and in response to stress. This implies that OsDT11 not only triggers strongly response to drought stress, but also alters several metabolic processes to enhance drought tolerance. Gene expression profling suggests that OsDT11 confers drought tolerance by mediating an enhanced response to drought stress in an ABA-dependent signaling pathways.