Synthesis, Photophysical and Electrochemical Properties of Novel Conjugated Donor-Acceptor Molecules Based on Phenothiazine and Benzimidazole

Zhang, Xiao-Hang,Kim, Seon-Ho,Lee, In-Su,Gao, Chun-Ji,Yang, Sung-Ik,Ahn, Kwang-Hyun Korean Chemical Society 2007 Bulletin of the Korean Chemical Society Vol.28 No.8

Two series of new organic fluorophores such as asymmetrical 3-(benzimidazol-2-yl)-10-hexylphenothiazine derivatives 1 and symmetrical 3,7-bis(benzimidazol-2-yl)-10-hexylphenothiazine derivatives 2 have been synthesized. Electronic absorption, fluorescence, and electrochemistry measurements reveal that the electron withdrawing benzimidazole subunit directly connected to the phenothiazine core facilitates the charge transfer characters which were also verified by the theoretical calculations. Various substituents on the benzimidazole moieties can allow a fine-tuning of the LUMO energy levels of the molecules without significantly affecting the HOMO energy levels. The method provides a new route for designing ambipolar molecules whose energy levels are well-matched with the Fermi levels of the electrodes to facilitate the electron or hole injection/transfer in OLED devices.

Detection of Cucumber Powdery Mildew Based on Spectral and Image Information

Xu Ji Tong,Zhang Zhe,Guo Yu Hang,Liu Yufeng,Ning Xiao Feng 한국농업기계학회 2023 바이오시스템공학 Vol.48 No.2

Purpose The aim of this study was to fi nd the optimal detection method for cucumber powdery mildew and improve the identifi cation effi ciency. Methods Image segmentation technology was used to extract spot images and grade classifi cation of powdery mildew. The relationship between powdery mildew spot and spectral refl ectance and intensity was studied. The powdery mildew detection model was established by using qualitative analysis and quantitative prediction methods combined with greenness ( a* ) indices of cucumber leaves. Results There were strong positive correlations between greenness and spectrum in some characteristic bands. Through the extraction of disease spot images and disease classifi cation, it was found that the higher the disease grade of leaves was, the higher the spectral refl ectivity and fl uorescence intensity. In the quantitative prediction model, the R 2 of the NIR spectrum was improved (0.8742) after MSC and SPA, and the eff ect of the fl uorescence spectrum model was not ideal. In the qualitative discriminant model, KNN and ensemble subspace discriminant were obtained for two kinds of spectra, and the identifi cation accuracy of the qualitative model was 97.5% after verifi cation. Conclusion An NIR spectral model can be used for the quantitative prediction of cucumber powdery mildew. The qualitative discriminant model had high accuracy for cucumber powdery mildew.

Synthesis, Photophysical and Electrochemical Properties of Novel Conjugated Donor-Acceptor Molecules Based on Phenothiazine and Benzimidazole

Xiao-Hang Zhang,Seon Ho Kim,In Su Lee,Chun Ji Gao,Sung Ik Yang*,Kwang-Hyun Ahn* 대한화학회 2007 Bulletin of the Korean Chemical Society Vol.28 No.8

Two series of new organic fluorophores such as asymmetrical 3-(benzimidazol-2-yl)-10-hexylphenothiazine derivatives 1 and symmetrical 3,7-bis(benzimidazol-2-yl)-10-hexylphenothiazine derivatives 2 have been synthesized. Electronic absorption, fluorescence, and electrochemistry measurements reveal that the electron withdrawing benzimidazole subunit directly connected to the phenothiazine core facilitates the charge transfer characters which were also verified by the theoretical calculations. Various substituents on the benzimidazole moieties can allow a fine-tuning of the LUMO energy levels of the molecules without significantly affecting the HOMO energy levels. The method provides a new route for designing ambipolar molecules whose energy levels are well-matched with the Fermi levels of the electrodes to facilitate the electron or hole injection/transfer in OLED devices.

Fracture behavior of fly ash concrete containing silica fume

Peng Zhang,Ji-Xiang Gao,Xiao-Bing Dai,Tian-Hang Zhang,Juan Wang 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.59 No.2

Effect of silica fume on fresh properties, compressive strength at 28 days and fracture behavior of fly ash concrete composite were studied in this paper. Test results indicated that the fluidity and flowability of fly ash concrete composites decreased and fly ash concrete composite are more cohesive and appear to be sticky with the addition of silica fume. Addition of silica fume was very effective in improving the compressive strength at 28 days of fly ash concrete composite, and the compressive strength of fly ash concrete composite has a trend of increase with the increase of silica fume content. Results also indicated that all the fracture parameters of effective crack length, fracture toughness, fracture energy, the critical crack opening displacement and the maximum crack opening displacement of fly ash concrete composite decreased with the addition of silica fume. When the content of silica fume increased from 3% to 12%, these fracture parameters decreased gradually with the increase of silica fume content. Furthermore, silica fume had great effect on the relational curves of the three-point bending beam specimen. As the silica fume content increased from 3% to 12%, the areas surrounded by the three relational curves and the axes were becoming smaller and smaller, which indicated that the capability of concrete composite containing fly ash to resist crack propagation was becoming weaker and weaker.

Blue organic light-emitting diodes with 2-methyl-9,10- bis(naphthalen-2-yl)anthracene as hole transport and emitting layer and the impedance spectroscopy analysis

Xiao-Wen Zhang,Bing-Jie Mo,Li-Ming Liu,Hong-Hang Wang,Dan-Teng Chang,Ji-Wen Xu,Hua Wang,Bin Wei 한국물리학회 2014 Current Applied Physics Vol.14 No.11

2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN) based fluorescent blue organic light-emitting diodes (OLEDs) are demonstrated. With MADN as emitting layer, experiments indicate that thick MADN (40e60 nm) is preferable for constructing efficient blue OLED. With MADN as hole-transport and emitting layer and tris(8-hydroxy-quinolinato)aluminium (Alq3) as electron-transport layer, the OLED electroluminescent characteristics show a mixture emission of MADN and Alq3 with Commission Internationale d'Eclairage (CIE) color coordinates of (0.25, 0.34), indicating feasible hole transporting in MADN. Using 4,7-diphenyl-1,10-phenanthroline (BPhen) replacing Alq3 as electron-transport layer, the OLED shows deep blue emission with a maximum luminous efficiency of 4.8 cd/A and CIE color coordinates of (0.16, 0.09). The hole transport characteristics of MADN are further clarified by constructing hole-only device and performing impedance spectroscopy analysis. The results indicate that MADN shows superior hole-transport ability which is almost comparable to typical hole-transport material of N,N0-bis(naphthalen-1-yl)-N,N0-bis(phenyl)-benzidine (NPB), suggesting a promising application for constructing efficient blue OLED with integrated hole-transport layer and emitting layer.

A20 ameliorates disc degeneration by suppressing mTOR/BNIP3 axis-mediated mitophagy

Peng Xin,Zhang Cong,Gao Jia-Wei,Wang Feng,Bao Jun-Ping,Zhou Zhi-Min,Sun Rui,Ji Hang-Yu,VLF Cabral,Wu Xiao-Tao 한국유전학회 2023 Genes & Genomics Vol.45 No.5

Background The pathological mechanism of intervertebral disc degeneration (IDD) is an unanswered question that we are committed to exploring. A20 is an anti-inflammatory protein of nucleus pulposus (NP) cells and plays a protective role in intervertebral disc degeneration. Objective This study aims to investigate the molecular mechanism by which A20 attenuates disc degeneration. Methods The proteins of interest were measured by immunoblotting, immunofluorescence, ELISA assay, and immunohistochemical technique to conduct related experiments. Immunofluorescence assays and mitochondrial membrane potential (JC-1) were used to assess mitophagy and mitochondrial fitness, respectively. Results Here, we demonstrated that A20 promoted mitophagy, attenuated pyroptosis, and inhibited the degradation of the extracellular matrix, consequently significantly ameliorating disc degeneration. Mechanistically, A20 reduces pyroptosis and further suppresses cellular mTOR activity. On the one hand, A20-induced mTOR inhibition triggers BNIP3-mediated mitophagy to ensure mitochondrial fitness under LPS stimulation, as a result of mitigating mitochondrial dysfunction induced by LPS. On the other hand, A20-induced mTOR inhibition reduces the loss of mitochondrial membrane potential and the generation of Mitochondrial ROS. Conclusion The study revealed that A20 promotes BNIP3-mediated mitophagy by suppressing mTOR pathway activation against LPS-induced pyroptosis.

Combining Non-Contrast CT Signs With Onset-to-Imaging Time to Predict the Evolution of Intracerebral Hemorrhage

Song Lei,Qiu Xiaoming,Zhang Cun,Zhou Hang,Guo Wenmin,Ye Yu,Wang Rujia,Xiong Hui,Zhang Ji,Tang Dongfang,Zou Liwei,Wang Longsheng,Yu Yongqiang,Guo Tingting 대한영상의학회 2024 Korean Journal of Radiology Vol.25 No.2

Objective: This study aimed to determine the predictive performance of non-contrast CT (NCCT) signs for hemorrhagic growth after intracerebral hemorrhage (ICH) when stratified by onset-to-imaging time (OIT). Materials and Methods: 1488 supratentorial ICH within 6 h of onset were consecutively recruited from six centers between January 2018 and August 2022. NCCT signs were classified according to density (hypodensities, swirl sign, black hole sign, blend sign, fluid level, and heterogeneous density) and shape (island sign, satellite sign, and irregular shape) features. Multivariable logistic regression was used to evaluate the association between NCCT signs and three types of hemorrhagic growth: hematoma expansion (HE), intraventricular hemorrhage growth (IVHG), and revised HE (RHE). The performance of the NCCT signs was evaluated using the positive predictive value (PPV) stratified by OIT. Results: Multivariable analysis showed that hypodensities were an independent predictor of HE (adjusted odds ratio [95% confidence interval] of 7.99 [4.87–13.40]), IVHG (3.64 [2.15–6.24]), and RHE (7.90 [4.93–12.90]). Similarly, OIT (for a 1-h increase) was an independent inverse predictor of HE (0.59 [0.52–0.66]), IVHG (0.72 [0.64–0.81]), and RHE (0.61 [0.54– 0.67]). Blend and island signs were independently associated with HE and RHE (10.60 [7.36–15.30] and 10.10 [7.10–14.60], respectively, for the blend sign and 2.75 [1.64–4.67] and 2.62 [1.60–4.30], respectively, for the island sign). Hypodensities demonstrated low PPVs of 0.41 (110/269) or lower for IVHG when stratified by OIT. When OIT was ≤ 2 h, the PPVs of hypodensities, blend sign, and island sign for RHE were 0.80 (215/269), 0.90 (142/157), and 0.83 (103/124), respectively. Conclusion: Hypodensities, blend sign, and island sign were the best NCCT predictors of RHE when OIT was ≤ 2 h. NCCT signs may assist in earlier recognition of the risk of hemorrhagic growth and guide early intervention to prevent neurological deterioration resulting from hemorrhagic growth.

Inhibition of Store-Operated Calcium Entry Protects Endothelial Progenitor Cells from H2O2-Induced Apoptosis

( Yan Wei Wang ),( Ji Hang Zhang ),( Yang Yu ),( Jie Yu ),( Lan Huang ) 한국응용약물학회 2016 Biomolecules & Therapeutics(구 응용약물학회지) Vol.24 No.4

Store-operated calcium entry (SOCE), a major mode of extracellular calcium entry, plays roles in a variety of cell activities. Accumulating evidence indicates that the intracellular calcium ion concentration and calcium signaling are critical for the responses induced by oxidative stress. The present study was designed to investigate the potential effect of SOCE inhibition on H2O2-induced apoptosis in endothelial progenitor cells (EPCs), which are the predominant cells involved in endothelial repair. The results showed that H2O2-induced EPC apoptosis was reversed by SOCE inhibition induced either using the SOCE antagonist ML-9 or via silencing of stromal interaction molecule 1 (STIM1), a component of SOCE. Furthermore, SOCE inhibition repressed the increases in intracellular reactive oxygen species (ROS) levels and endoplasmic reticulum (ER) stress and ameliorated the mitochondrial dysfunction caused by H2O2. Our findings provide evidence that SOCE inhibition exerts a protective effect on EPCs in response to oxidative stress induced by H2O2 and may serve as a potential therapeutic strategy against vascular endothelial injury.

Inhibition of Store-Operated Calcium Entry Protects Endothelial Progenitor Cells from H₂O₂-Induced Apoptosis

Wang, Yan-Wei,Zhang, Ji-Hang,Yu, Yang,Yu, Jie,Huang, Lan The Korean Society of Applied Pharmacology 2016 Biomolecules & Therapeutics(구 응용약물학회지) Vol.24 No.4

Store-operated calcium entry (SOCE), a major mode of extracellular calcium entry, plays roles in a variety of cell activities. Accumulating evidence indicates that the intracellular calcium ion concentration and calcium signaling are critical for the responses induced by oxidative stress. The present study was designed to investigate the potential effect of SOCE inhibition on $H_2O_2$-induced apoptosis in endothelial progenitor cells (EPCs), which are the predominant cells involved in endothelial repair. The results showed that $H_2O_2$-induced EPC apoptosis was reversed by SOCE inhibition induced either using the SOCE antagonist ML-9 or via silencing of stromal interaction molecule 1 (STIM1), a component of SOCE. Furthermore, SOCE inhibition repressed the increases in intracellular reactive oxygen species (ROS) levels and endoplasmic reticulum (ER) stress and ameliorated the mitochondrial dysfunction caused by $H_2O_2$. Our findings provide evidence that SOCE inhibition exerts a protective effect on EPCs in response to oxidative stress induced by $H_2O_2$ and may serve as a potential therapeutic strategy against vascular endothelial injury.

Thermal Stress Field and Microstructure Evolution of Ti-6Al-4V Fabricated by Laser Engineered Net Shaping

Liukui Hu,Jiwang Zhang,Hang Li,Kaixin Su,Dongdong Ji 대한금속·재료학회 2024 METALS AND MATERIALS International Vol.30 No.2

To investigate the thermal stress field and microstructure evolution of Ti-6Al-4V alloy component produced by laser engineerednet shaping (LENS), numerical simulations are performed at both macroscale and mesoscale. At the macroscale,a finite element model is developed and validated by comparing the simulated residual stress with the measured residualstress. Meanwhile, the effect of scanning strategies on residual stress is analyzed. At the mesoscale, a three-dimensional(3D) cellular automaton model is established to analyze the growth mechanism of β-columnar grains. The results show thatthe maximum residual stress locates at the surrounding area at the interface between the substrate and the cladding layer. Based on the results under the unidirectional and reciprocating scanning strategies, the residual stress of the component isminimized by using the reciprocating alternating scanning strategy. Due to the higher temperature gradient at the bottomof the molten pool, β-columnar grains grow epitaxially from the pre-existing grains in the substrate. When the direction ofdendritic growth is consistent with the direction of the temperature gradient, grain growth is faster and there is a clear preferredorientation, which ultimately forms β-columnar grain structures that tilt towards the scanning direction and penetratemultiple cladding layers.