Preparation of oral nanoemulsion drug delivery system loaded with punicalagin: in vitro antibacterial activity, drug release, and cell safety studies

Fei‑Fei Shi,Yu‑Juan Mao,Ying Wang,Hai‑Feng Yang 한국고분자학회 2024 Macromolecular Research Vol.32 No.3

The objective of the present study was to develop a W/O/W nanoemulsion (NE) drug delivery system loaded with punicalagin (PGN) for oral delivery and evaluate its potential in antibacterial therapy. The W/O/W PGN-NE was prepared using a two-step process by combining ultrasonic with high-energy emulsification and subsequently characterized by its droplet size, zeta potential, and morphology. The PGN-NE was further evaluated for its pH, in vitro antibacterial activity, drug release property, and cytotoxicity. The results indicated the formation of spherical, nano-sized globules of PGN-NE had a mean particle size of 45.53 ± 2.2 nm, with a PDI value of 0.22 ± 0.028, zeta potential was −4.67 ± 0.88 mV, and pH value was 5.8. In vitro antibacterial activity studies showed a significantly higher antibacterial activity of PGN-NE in comparison to free PGN, suggesting that NE can effectively improve the antibacterial effect of natural pharmaceuticals. The drug release assay demonstrated that PGN was slowly released from the NE preparation and absorbed, helping to prolong the potency and improve the bioavailability of PGN. Cytotoxicity testing showed that PGN had reduced toxicity when encapsulated in NE. Thus, the developed NE formulation of PNG exhibited a greater potential for the slow-release effect delivery and in the treatment of microbial infections with favorable safety profile.

A Cluster-Based Countermeasure against MAC Layer Attacks in IEEE 802.11 MANETs

Shi, Fei,Liu, Wei Jie,Jin, Dong Xu,Song, Joo Seok Trans Tech Publications, Ltd. 2013 Applied mechanics and materials Vol.284 No.-

<P>MANETs become a considerable interest nowadays. However, these types of networks are vulnerable to a large group of attacks, e.g., MAC layer attacks. Most of the previous researches related to security issues focus on detection of misbehaviors after it occurred. We propose a new way of thinking to evade occurrence of misbehaviors. A novel clustering algorithm is presented using analytic hierarchy process to elect clusterhead. Afterwards, the clusterhead is required to assign backoff values to originators in its transmission range, which are also the members in the corresponding cluster, rather than permitting the originators to choose backoff values. Meanwhile, the elected clusterhead also monitors whether originators obey the backoff values. With the proposed scheme, the misuse of the backoff in MAC layer in 802.11 DCF can be prevented.</P>

Kinetics of Transesterification of 1,4-Butanediol With Methyl Acetate by the Ion-exchange Resin

Fei Shi,Guo Bing Li,Hong Liang Sun,Wang Feng Cai 대한화학회 2017 Bulletin of the Korean Chemical Society Vol.38 No.3

The dihydric alcohol transesterification of 1,4-butanediol with methyl acetate catalyzed by the ion-exchange resin is researched. The chemical system involves two transesterification reactions in series, with 1,4-butanediol monoacetate as an intermediate product. The effects of the catalyst type, catalyst size, catalyst loading, stirrer speed, the initial reactant ratio, and the reactive temperature have been meticulously studied. The results show that this consecutive transesterification is exothermic and the experimental values of reaction enthalpy are −8.50 and −6.85 kJ/mol, which are in good agreement with the values computed from the standard formation enthalpy. Three kinetic models (PH, LH, and ER) are applied to correlate the experimental data, of which ER model gives the best result with the lowest mean relative error. The activation energies are calculated to be 38.53 and 51.06 kJ/mol by ER model, demonstrating that the overall reaction rates are controlled by the reaction on the catalyst surface.

A cluster-based countermeasure against blackhole attacks in MANETs

Shi, Fei,Liu, Weijie,Jin, Dongxu,Song, Jooseok Springer-Verlag 2014 Journal of Telecommunication systems Vol.57 No.2

A Cluster-based Countermeasure against Media Access Control Layer Attacks in IEEE 802.11 Ad Hoc Networks

( Fei Shi ),( Jooseok Song ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.6

The characteristics of ad hoc networks, such as the absence of infrastructure, a dynamic topology, a shared wireless medium and a resource-constrained environment pose various security challenges. Most previous studies focused on the detection of misbehavior after it had occurred. However, in this paper we propose a new way of thinking to evade the occurrence of misbehavior. In our scheme, we firstly present a clustering algorithm that employs a powerful analytic hierarchy process methodology to elect a clusterhead for each cluster. The clusterhead in each cluster is then allowed to assign the backoff values to its members, i.e., originators, rather than permitting the originators to choose the backoff values by themselves. Through this media access control layer misbehavior detection mechanism, the misuse of the backoff in the media access control layer in the 802.11 distributed coordination function can be detected.

miR-98 suppresses melanoma metastasis through a negative feedback loop with its target gene IL-6

Fei Li,Xin-ji Li,Li Qiao,Fei Shi,Wen Liu,You Li,Yu-ping Dang,Weijie Gu,Xiao-gang Wang,Wei Liu 생화학분자생물학회 2014 Experimental and molecular medicine Vol.46 No.-

Dysregulated microRNA (miRNA) expression has a critical role in tumor development and metastasis. However, the mechanism by which miRNAs control melanoma metastasis is unknown. Here, we report reduced miR-98 expression in melanoma tissues with increasing tumor stage as well as metastasis; its expression is also negatively associated with melanoma patient survival. Furthermore, we demonstrate that miR-98 inhibits melanoma cell migration in vitro as well as metastatic tumor size in vivo. We also found that IL-6 is a target gene of miR-98, and IL-6 represses miR-98 levels via the Stat3-NF-κB-lin28B pathway. In an in vivo melanoma model, we demonstrate that miR-98 reduces melanoma metastasis and increases survival in part by reducing IL-6 levels; it also decreases Stat3 and p65 phosphorylation as well as lin28B mRNA levels. These results suggest that miR-98 inhibits melanoma metastasis in part through a novel miR-98-IL-6-negative feedback loop.

Combining Model-based and Heuristic Techniques for Fast Tracking the Global Maximum Power Point of a Photovoltaic String

Shi, Ji-Ying,Xue, Fei,Ling, Le-Tao,Li, Xiao-Fei,Qin, Zi-Jian,Li, Ya-Jing,Yang, Ting The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2

Under partial shading conditions (PSCs), multiple maximums may be exhibited on the P-U curve of string inverter photovoltaic (PV) systems. Under such conditions, heuristic methods are invalid for extracting a global maximum power point (GMPP); intelligent algorithms are time-consuming; and model-based methods are complex and costly. To overcome these shortcomings, a novel hybrid MPPT (MPF-IP&O) based on a model-based peak forecasting (MPF) method and an improved perturbation and observation (IP&O) method is proposed. The MPF considers the influence of temperature and does not require solar radiation measurements. In addition, it can forecast all of the peak values of the PV string without complex computation under PSCs, and it can determine the candidate GMPP after a comparison. Hence, the MPF narrows the searching range tremendously and accelerates the convergence to the GMPP. Additionally, the IP&O with a successive approximation strategy searches for the real GMPP in the neighborhood of the candidate one, which can significantly enhance the tracking efficiency. Finally, simulation and experiment results show that the proposed method has a higher tracking speed and accuracy than the perturbation and observation (P&O) and particle swarm optimization (PSO) methods under PSCs.

무용전공 여중생의 신체구성과 체력과의 관계분석

사붕비 ( Shi Peng-fei ),오수일 ( Oh Su-ill ),황예선 ( Hwang Ye-seon ) 대한무용학회 2017 대한무용학회논문집 Vol.75 No.3

This study examined the relations between body composition and phys-ical fitness, targeting 17 middle school girls with dance major. In the body composition, the group of skilled showed significantly high fat free mass. In the physical fitness, the group of skilled significantly high muscular strength and flexibility. In the correlations, the weight, BMI, and fat free mass of body composition showed the significantly pos-itive correlations with muscular strength and their influence were 52.9%, 36.7%, 64.5% respectively. The body fat percentage showed the negative correlations with quickness and cardiorespiratory endurance and their in-fluences were 31.4% and 29.2% respectively.

Combining Model-based and Heuristic Techniques for Fast Tracking the Global Maximum Power Point of a Photovoltaic String

Ji-Ying Shi,Fei Xue,Le-Tao Ling,Xiao-Fei Li,Zi-Jian Qin,Ya-Jing Li,Ting Yang 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2

Under partial shading conditions (PSCs), multiple maximums may be exhibited on the P-U curve of string inverter photovoltaic (PV) systems. Under such conditions, heuristic methods are invalid for extracting a global maximum power point (GMPP); intelligent algorithms are time-consuming; and model-based methods are complex and costly. To overcome these shortcomings, a novel hybrid MPPT (MPF-IP&O) based on a model-based peak forecasting (MPF) method and an improved perturbation and observation (IP&O) method is proposed. The MPF considers the influence of temperature and does not require solar radiation measurements. In addition, it can forecast all of the peak values of the PV string without complex computation under PSCs, and it can determine the candidate GMPP after a comparison. Hence, the MPF narrows the searching range tremendously and accelerates the convergence to the GMPP. Additionally, the IP&O with a successive approximation strategy searches for the real GMPP in the neighborhood of the candidate one, which can significantly enhance the tracking efficiency. Finally, simulation and experiment results show that the proposed method has a higher tracking speed and accuracy than the perturbation and observation (P&O) and particle swarm optimization (PSO) methods under PSCs.

Localization of α-, γ-, and δ-tubulin in the hypotrich ciliate Stylonychia pustulata (Hyportrichida, Ciliophora)

Fei Yin,Fukang Gu,Xin Sheng,Quanxin Gao,Qili Li,Zhaohong Shi 한국통합생물학회 2013 Animal cells and systems Vol.17 No.4

Ciliature microtubular organelles, which organize into ciliary units, are highly complex microtubular systems. Toinvestigate the formation of ciliature microtubular organelles and the role that different tubulins play in this process,we examined the distribution and function of α-, γ-, and δ-tubulins in the hypotrich ciliate Stylonychia pustulata. Immunofluorescence analysis demonstrated that α-tubulin localized to all microtubular organelles, while γ- and δ-tubulinscolocalized at basal bodies. Immunogold labeling revealed that γ- and δ-tubulins colocalize to the proximalpart of basal bodies, suggesting that γ- and δ-tubulins probably interact and may function together. In addition, thepermanent localization of γ-tubulin to the adoral zone of membranelles suggests that γ-tubulin play a role in themaintenance of oral ciliature base-associated microtubules, but does not play a role in the biogenesis of theseciliature. We observe that δ-tubulin is restricted to the basal body and the connective fibers of the basal body,suggesting this protein may be required for the extension and stability of the microtubules in these structures. Dramatically different concentrations of these three tubulins were observed in the cytoskeleton and the insoluble andsoluble fractions of the cell, suggesting that these highly related proteins perform different functions in S. pustulata.