Antibacterial activity of a novel florfenicol-loaded chitosan-sodium tripolyphosphate composite nanogels in vitro and in mice against Staphylococcus aureus small colony variants

Jinhuan Liu,Mujie Ju,Yifei Wu,Nannan Leng,Samah Attia Algharib,Wanhe Luo 대한수의학회 2022 Journal of Veterinary Science Vol.23 No.5

Background: Florfenicol might be ineffective for treating Staphylococcus aureus small colony variants (SCVs) mastitis. Objectives: In this study, florfenicol-loaded chitosan (CS)-sodium tripolyphosphate (TPP) composite nanogels were prepared to allow targeted delivery to SCV infected sites. Methods: The formulation screening, the characteristics, in vitro release, antibacterial activity, therapeutic efficacy, and biosafety of the florfenicol composite nanogels were studied. Results: The optimized formulation was obtained when the CS and TPP were 10 and 5 mg/mL, respectively. The encapsulation efficiency, loading capacity, size, polydispersity index, and zeta potential of the optimized florfenicol composite nanogels were 87.3% ± 2.7%, 5.8% ± 1.4%, 280.3 ± 1.5 nm, 0.15 ± 0.03, and 36.3 ± 1.4 mv, respectively. Optical and scanning electron microscopy showed that spherical particles with a relatively uniform distribution and drugs might be incorporated in cross-linked polymeric networks. The in vitro release study showed that the florfenicol composite nanogels exhibited a biphasic pattern with the sustained release of 72.2% ± 1.8% at 48 h in pH 5.5 phosphate-buffered saline. The minimal inhibitory concentrations of commercial florfenicol solution and florfenicol composite nanogels against SCVs were 1 and 0.25 μg/mL, respectively. The time-killing curves and live–dead bacterial staining showed that the florfenicol composite nanogels were concentration-dependent. Furthermore, the florfenicol composite nanogels displayed good therapeutic efficacy against SCVs mastitis. Biological safety studies showed that the florfenicol composite nanogels might be a biocompatible preparation because of their non-toxic effects on the renal tissue and liver. Conclusions: Florfenicol composite nanogels might improve the treatment of SCV infections.

An Optimal Schedule Algorithm Trade-Off Among Lifetime, Sink Aggregated Information and Sample Cycle for Wireless Sensor Networks

Jinhuan Zhang,Jun Long,Anfeng Liu,Guihu Zhao 한국통신학회 2016 Journal of communications and networks Vol.18 No.2

Data collection is a key function for wireless sensor networks. There has been numerous data collection scheduling algorithms,but they fail to consider the deep and complex relationshipamong network lifetime, sink aggregated information and samplecycle for wireless sensor networks. This paper gives the upperbound on the sample period under the given network topology. An optimal schedule algorithm focusing on aggregated informationnamed OSFAI is proposed. In the schedule algorithm, the nodesin hotspots would hold on transmission and accumulate their databefore sending them to sink at once. This could realize the dualgoals of improving the network lifetime and increasing the amountof information aggregated to sink. We formulate the optimizationproblem as to achieve trade-off among sample cycle, sink aggregatedinformation and network lifetime by controlling the samplecycle. The results of simulation on the random generated wirelesssensor networks show that when choosing the optimized sample cycle,the sink aggregated information quantity can be increased by30.5%, and the network lifetime can be increased by 27.78%.

Identification of root-preferential transcription factors in rice by analyzing GUS expression patterns of T-DNA tagging lines

Jinhuan Wei,Yunfei Wu,Lae-Hyeon Cho,Jinmi Yoon,Heebak Choi,Hyeryung Yoon,Ping Jin,Jakyung Yi,Yang-Seok Lee,Hee Joong Jeong,Jungil Yang,Gynheung An 한국식물학회 2017 Journal of Plant Biology Vol.60 No.3

T-DNA tagging lines are useful for analyzing the functions of genes and regulatory elements. We have previously generated approximately 100,000 insertional mutants in japonica rice (Oryza sativa), using T-DNA vectors carrying the promoter-less GUS reporter gene. In this study, we conducted GUS assays of seedlings from 430 lines in which TDNA was inserted into transcription factor genes. Among the 75 lines that showed GUS signals, nine displayed an endospermpreferential expression pattern; two lines demonstrated GUS signals in both endosperm and roots; 21 lines had GUS expression mainly in leaves; 19 lines showed GUS signal in both leaves and roots; and 24 lines expressed GUS predominantly in the roots. Co-segregation analyses of 49 homozygous lines indicated that the GUS expression patterns observed from 38 lines were due to the T-DNA insertion. We also identified fusion transcripts between tagged genes and the GUS reporter in six lines. Quantitative RT-PCR confirmed that the GUS expression patterns of those tagged lines indeed represent organ- and tissue-preferential expression of the tagged genes. The GUS-tagged transcription factor lines identified here will be useful for functional analysis of these candidates.

외국인 근로자의 융・복합적 문제점 및 제안

도진환 ( Jinhuan Du ) 사단법인 아시아문화학술원 2020 인문사회 21 Vol.11 No.6

본 연구는 우리나라가 고속도로 경제성장에 따른 산업구조 변화뿐만 아니라 노동인구 구조에도 변화가 생겼다. 한국은 제조업에 경제 기반을 둔 국가라 단순 기능직이나 3D 업종에서 많은 인력을 요구한다. 외국인 근로자의 유입은 계속해서 늘어가고 있다. 그렇기에 얼어붙은 한국 노동시장, 취업시장의 상황과 외국인 근로자 현황을 충분히 고려한 정책적인 접근 등이 계속되어야 할 것으로 보인다. 본 연구에서는 외국인 근로자에 관한 문제점 등을 정리하고 분석하여 사회학적, 사회복지학적, 법학적 측면에서 문제점을 살펴보면서 아래와 같은 제안을 제시하고자 한다. 첫째, 외국인 근로자의 사회에서의 인식적인 해결방안을 찾아야 한다. 둘째, 외국인 근로자는 보호받을 수 있는 권리가 노동관계법 일부에만 국한되어져 있어 사회 안전망과 같은 사회복지서비스 차원에서는 대책마련이 필요하다. 셋째, 외국인 근로자의 고용허가 요건 강화 및 고용 절차의 투명화 해야 한다. In this study, not only did Korea change the industrial structure due to the economic growth of highways, but also the structure of the working population. Korea is an economy-based country in manufacturing, requiring a large number of workers in simple functional or 3D industries. The influx of foreign workers continues to grow. That is why the frozen Korean labor market, the job market situation and the policy approach that fully considers the status of foreign workers should continue. In this study, we would like to present the following suggestions by summarizing and analyzing the problems concerning foreign workers and examining the problems in terms of sociological, social welfare and legal aspects. First, we need to find cognitive solutions in the society of foreign workers. Second, foreign workers’ right to be protected is limited to only part of the Labor Relations Act, so measures need to be taken at the level of social welfare services such as the social safety net. Third, the requirements for employment permit for foreign workers should be strengthened and the employment procedures should be transparent.

An Optimal Schedule Algorithm Trade-Off Among Lifetime, Sink Aggregated Information and Sample Cycle for Wireless Sensor Networks

Zhang, Jinhuan,Long, Jun,Liu, Anfeng,Zhao, Guihu The Korea Institute of Information and Commucation 2016 Journal of communications and networks Vol.18 No.2

Data collection is a key function for wireless sensor networks. There has been numerous data collection scheduling algorithms, but they fail to consider the deep and complex relationship among network lifetime, sink aggregated information and sample cycle for wireless sensor networks. This paper gives the upper bound on the sample period under the given network topology. An optimal schedule algorithm focusing on aggregated information named OSFAI is proposed. In the schedule algorithm, the nodes in hotspots would hold on transmission and accumulate their data before sending them to sink at once. This could realize the dual goals of improving the network lifetime and increasing the amount of information aggregated to sink. We formulate the optimization problem as to achieve trade-off among sample cycle, sink aggregated information and network lifetime by controlling the sample cycle. The results of simulation on the random generated wireless sensor networks show that when choosing the optimized sample cycle, the sink aggregated information quantity can be increased by 30.5%, and the network lifetime can be increased by 27.78%.

Antibacterial activity of florfenicol composite nanogels against Staphylococcus aureus small colony variants

Liu, Jinhuan,Ju, Mujie,Wu, Yifei,Leng, Nannan,Algharib, Samah Attia,Luo, Wanhe The Korean Society of Veterinary Science 2022 Journal of Veterinary Science Vol.23 No.5

Background: Florfenicol might be ineffective for treating Staphylococcus aureus small colony variants (SCVs) mastitis. Objectives: In this study, florfenicol-loaded chitosan (CS)-sodium tripolyphosphate (TPP) composite nanogels were prepared to allow targeted delivery to SCV infected sites. Methods: The formulation screening, the characteristics, in vitro release, antibacterial activity, therapeutic efficacy, and biosafety of the florfenicol composite nanogels were studied. Results: The optimized formulation was obtained when the CS and TPP were 10 and 5 mg/mL, respectively. The encapsulation efficiency, loading capacity, size, polydispersity index, and zeta potential of the optimized florfenicol composite nanogels were 87.3% ± 2.7%, 5.8% ± 1.4%, 280.3 ± 1.5 nm, 0.15 ± 0.03, and 36.3 ± 1.4 mv, respectively. Optical and scanning electron microscopy showed that spherical particles with a relatively uniform distribution and drugs might be incorporated in cross-linked polymeric networks. The in vitro release study showed that the florfenicol composite nanogels exhibited a biphasic pattern with the sustained release of 72.2% ± 1.8% at 48 h in pH 5.5 phosphate-buffered saline. The minimal inhibitory concentrations of commercial florfenicol solution and florfenicol composite nanogels against SCVs were 1 and 0.25 ㎍/mL, respectively. The time-killing curves and live-dead bacterial staining showed that the florfenicol composite nanogels were concentration-dependent. Furthermore, the florfenicol composite nanogels displayed good therapeutic efficacy against SCVs mastitis. Biological safety studies showed that the florfenicol composite nanogels might be a biocompatible preparation because of their non-toxic effects on the renal tissue and liver. Conclusions: Florfenicol composite nanogels might improve the treatment of SCV infections.

Advanced Droop Control Scheme in Multi-terminal DC Transmission Systems

Yanbo Che,Jinhuan Zhou,Wenxun Li,Jiebei Zhu,Chao Hong 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.3

Droop control schemes have been widely employed in the control strategies for Multi- Terminal Direct Current (MTDC) system for its high reliability. Under the conventional DC voltage-active power droop control, the droop slope applies a proportional relationship between DC voltage error and active power error for power sharing. Due to the existence of DC network impedance and renewable resource fluctuation, there is inevitably a DC voltage deviation from the droop characteristic, which in turn results in inaccurate control of converter’s power. To tackle this issue, a piecewise droop control with DC voltage dead band or active power dead band is implemented into controller design. Besides, an advanced droop control scheme with versatile function is proposed, which enables the converter to regulate DC voltage and AC voltage, control active and reactive power, get participated into frequency control, and feed passive network. The effectiveness of the proposed control method has been verified by simulation results.

Synthesis, Characterization and Antioxidant Activity of a Novel Organogermanium Sesquioxide with Resveratrol

Shuguang Yao,Jinhuan Jiang,Peihui Yang,Jiye Cai 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.4

Theoretical investigations on the orientational dependence of electron transport through porphyrin molecular wire

Yanwei Li,Jinhuan Yao,Shengkui Zhong,Zhengguang Zou 한국물리학회 2011 Current Applied Physics Vol.11 No.6

The effect of molecular orientation on the electron transport behavior of single porphyrin sandwiched between two gold (111) electrodes is investigated by density functional theory calculations combined with non-equilibrium Green’s function method. The results show that the porphyrin with parallel connection to gold (111) electrodes is more conductive than the porphyrin with diagonal connection to gold (111) electrodes. The mechanism of the difference of electron transport for these two molecular junctions is analyzed from the transmission spectra and the molecular projected self-consistent Hamiltonian states. It is found that the intrinsic nature of the molecule, such as the π-conjugated framework and the strength of molecule―electrode coupling, are the essential reason for generating this difference of electron transport for the two molecular systems.

Enhanced antibacterial activity of tilmicosin against Staphylococcus aureus small colony variants by chitosan oligosaccharide-sodium carboxymethyl cellulose composite nanogels

Wanhe Luo,Jinhuan Liu,Shanling Zhang,Wei Song,Samah Attia Algharib,Wei Chen 대한수의학회 2022 Journal of Veterinary Science Vol.23 No.1

Background: The poor bioadhesion capacity of tilmicosin resulting in treatment failure for Staphylococcus aureus small colony variants (SASCVs) mastitis. Objectives: This study aimed to increase the bioadhesion capacity of tilmicosin for the SASCVs strain and improve the antibacterial effect of tilmicosin against cow mastitis caused by the SASCVs strain. Methods: Tilmicosin-loaded chitosan oligosaccharide (COS)-sodium carboxymethyl cellulose (CMC) composite nanogels were formulated by an electrostatic interaction between COS (positive charge) and CMC (negative charge) using sodium tripolyphosphate (TPP) (ionic crosslinkers). The formation mechanism, structural characteristics, bioadhesion, and antibacterial activity of tilmicosin composite nanogels were studied systematically. Results: The optimized formulation was comprised of 50 mg/mL (COS), 32 mg/mL (CMC), and 0.25 mg/mL (TPP). The size, encapsulation efficiency, loading capacity, polydispersity index, and zeta potential of the optimized tilmicosin composite nanogels were 357.4 ± 2.6 nm, 65.4 ± 0.4%, 21.9 ± 0.4%, 0.11 ± 0.01, and -37.1 ± 0.4 mV, respectively; the sedimentation rate was one. Scanning electron microscopy showed that tilmicosin might be incorporated in nano-sized crosslinked polymeric networks. Moreover, adhesive studies suggested that tilmicosin composite nanogels could enhance the bioadhesion capacity of tilmicosin for the SASCVs strain. The inhibition zone of native tilmicosin, tilmicosin standard, and tilmicosin composite nanogels were 2.13 ± 0.07, 3.35 ± 0.11, and 1.46 ± 0.04 cm, respectively. The minimum inhibitory concentration of native tilmicosin, tilmicosin standard, and tilmicosin composite nanogels against the SASCVs strain were 2, 1, and 1 μg/mL, respectively. The in vitro time-killing curves showed that the tilmicosin composite nanogels increased the antibacterial activity against the SASCVs strain. Conclusions: This study provides a potential strategy for developing tilmicosin composite nanogels to treat cow mastitis caused by the SASCVs strain.