Effect of Li Content on the Surface Film Formed on the Binary Mg–Li Alloys in NaCl Solution

Chuanqiang Li,Dahui Liang,Yejia Lin,Yong Dong,Binqing Shi,Changjian Yan,Zhengrong Zhang 대한금속·재료학회 2024 METALS AND MATERIALS International Vol.30 No.1

The surface film formed on the Mg–Li alloys with different Li content in 0.1 M NaCl solution were investigated via electrochemicaltesting, morphologies observation and chemical composition analysis in this work. The results revealed that thesurface film of Mg–14Li alloy (L14: body centred cubic (BCC)) possessed higher electrical resistivity and remained a highertolerating over-potential (0.1 V vs. open circuit potential) than those of Mg–4Li (L4: hexagonal closed-packed (HCP)) andMg–7.5Li (L7: HCP+BCC), resulting in a better corrosion performance. After 24 h immersion in NaCl solution, the wholesurface film of L14 remained undamaged and displayed weave-like and dense characteristic, while both L4 and L7 present aseverely damaged film. The cross-sectional details illustrated typical two layers of surface film formed on L14 with the outerlayer of ~ 1.5 μm and inner layer of ~ 2.5 μm in thickness, whilst only one layer of film with less than 2.5 μm in thicknesswas observed on L4 and L7. At last, combining analysis of X-ray diffraction, energy dispersive X-ray spectrometry, X-rayphotoelectron spectroscopy and transmission electron microscope confirmed the composition of outer layer of surface filmon the L14 contains much more Mg(OH)2 and Li-containing compounds, and the porous Mg(OH)2 film can be sealed by theLi-containing compounds, which is very different the single Mg(OH)2 film on the traditional magnesium and L4/L7 alloys. As a result, the best protective function of the surface film on the L14 alloy contribute to its high corrosion resistance.

Identification and characterization of heat shock proteins in a parasitic wasp Chouioia cuneae (Hymenoptera: Eulophidae)

Li‐Na Pan,Feng-ZhuWANG,Xin-Yue ZHANG,Yan-Ni ZHAO,Geng-Ping ZHU,Min LI 한국곤충학회 2018 Entomological Research Vol.48 No.3

Heat shock proteins (HSPs) are known to be induced in response to various stress factors. Although HSPs have been studied in a number of insects, not much is known about HSPs in the natural enemies of insects, especially parasitoids. In this study, we identified and characterized five full‐length HSP genes (Cchsp40, Cchsp60, Cchsp70, Cchsp83, and Cchsp90) from an endoparasitic chalcid wasp, Chouioia cunea, which parasitizes the fall webworm, Hyphantria cunea pupae, a worldwide pest. The expression of Cchsps in response to temperature, pesticide stresses and UV radiation were also investigated by quantitative real‐time polymerase chain reaction (RT‐qPCR). The results showed that all five Cchsps were induced in response to hot and cold temperatures. Four pesticides induced the abundant expression of Cchsp70, Cchsp83 and Cchsp90 while ultraviolet radiation up‐regulated Cchsp40, Cchsp70, Cchsp83 and Cchsp90. These results indicate the different transcriptional profiles of the five different Cchsps in response to various abiotic stresses. The findings of this study provide insights into the response of C. cunea to abiotic stresses and insight into the use of this parasitoid in biological control strategies.

Static analysis of 2D-FG nonlocal porous tube using gradient strain theory and based on the first and higher-order beam theory

Xiaozhong Zhang,Jian-Feng Li,Yan Cui,Mostafa Habibi,H. Elhosiny Ali,Ibrahim AlBaijan,Tayebeh Mahmoudi 국제구조공학회 2023 Steel and Composite Structures, An International J Vol.49 No.3

This article focuses on the study of the buckling behavior of two-dimensional functionally graded (2D-FG) nanosize tubes, including porosity, based on the first shear deformation and higher-order theory of the tube. The nano-scale tube is simulated using the nonlocal gradient strain theory, and the general equations and boundary conditions are derived using Hamilton’s principle for the Zhang-Fu’s tube model (as a higher-order theory) and Timoshenko beam theory. Finally, the derived equations are solved using a numerical method for both simply-supported and clamped boundary conditions. A parametric study is performed to investigate the effects of different parameters, such as axial and radial FG power indices, porosity parameter, and nonlocal gradient strain parameters, on the buckling behavior of the bi-dimensional functionally graded porous tube. Keywords: Nonlocal strain gradient theory; buckling; Zhang-Fu’s tube model; Timoshenko theory; Two-dimensional functionally graded materials; Nanotubes; Higher-order theory.

Impact of electrolyte additives (alkali metal salts) on the capacitive behavior of NiO-based capacitors

Yong Zhang,Lizhen Wang,Aiqin Zhang,Yanhua Song,Xiaofeng Li,Xingbing Wu,Peipei Du,Lv Yan 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.2

To improve the specific capacitance and energy density of electrochemical capacitor, nanostructured NiO was prepared by high temperature solid-state method as electrode material. The crystal structure and morphology of as-parepared NiO samples were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Cyclic voltammetry (CV) measurement was applied to investigate the specific capacitance of the NiO electrode. Furthermore,a novel mixed electrolyte consisting of NaOH, KOH, LiOH and Li_2CO_3 was prepared for the NiO capacitor,and the component and concentration of the four different electrolytes was examined by orthogonal test. The results showed that the NiO sample has cubic structure with nano-size particles, and the optimal composition of the electrolyte was: NaOH 2 mol L^(−1), KOH 3 mol L^(−1), LiOH 0.05 mol L^(−1), and Li_2CO_3 0.05 mol L^−1. At a scan rate of 10 mV s^(−1), the fabricated capacitor exhibits excellent electrochemical capacitive performance, while the specific capacitance and the energy density were 239 F g^(−1) and 85 Wh kg^(−1), which was higher than one-component electrolyte.

Preparation of lithium-doped NaV6O15 thin film cathodes with high cycling performance in SIBs

Xu Hai-Yan,Ruan Jun Hai,Liu Fang Lin,Li Dong-Cai,Zhang Feng-Jun,Wang Ai-Guo,Sun Dao-Sheng,오원춘 한국세라믹학회 2022 한국세라믹학회지 Vol.59 No.3

Lithium ions-doped NaV6O15 thin films have been prepared using a simple low temperature liquid phase deposition method and subsequent annealing process. X-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), scanning elec- tron microscopy (SEM), and photoelectron spectroscopy (XPS) have been used to study the structural and physicochemical characteristics of the NaV6O15 film. The films were grown on the FTO conductive glass and used directly as an electrode of sodium ion batteries. The prepared lithium ions-doped NaV6O15 thin film electrodes showed an excellent cycling stability and discharge capacity, which may be attributed to the stability of the Li+ embedded into the gap between the V–O layers to maintain the structure and its stable β-phase structure transformed after the first cycle. The cycling stability greatly improved with increasing annealing temperature, while the discharge capacity decreased. The capacities of the film electrodes annealed at 400 °C and 450 °C maintained above 97% after 100 cycles. The lithium-doped NaV6O15 underwent a phase transition dur- ing the first charge/discharge cycle. The new transformed phase has perfect crystal structure stability undergoing insertion and deinsertion of Na+. Therefore, the lithium-doped NaV6O15 thin film possesses good cycling stability and is expected to be a promising thin film cathode for sodium-ion batteries.

Disruption of endothelial barrier function is linked with hyposecretion and lymphocytic infiltration in salivary glands of Sjögren's syndrome

Cong, Xin,Zhang, Xue-Ming,Zhang, Yan,Wei, Tai,He, Qi-Hua,Zhang, Li-Wei,Hua, Hong,Lee, Sang-Woo,Park, Kyungpyo,Yu, Guang-Yan,Wu, Li-Ling Elsevier 2018 Biochimica et biophysica acta. Molecular basis of Vol.1864 No.10

<P><B>Abstract</B></P> <P>Sjögren's syndrome (SS) is an inflammatory autoimmune disease that causes hyposecretion in salivary glands. Endothelial tight junctions (TJs) play crucial roles in salivation and barrier function of blood vessels. However, whether the alteration of endothelial TJs were involved in pathogenesis of SS was still unknown. Here, the ultrastructure and function of endothelial TJs in submandibular glands (SMGs) were detected by transmission electron microscopy and in vivo paracellular permeability assay in different aged NOD mouse model for SS. CFSE-labeled lymphocytes were injected into tail vein to trace the infiltration, while claudin-5 expression and distribution were detected by immunofluorescence, qRT-PCR, and western blot. Results showed that the stimulated salivary flow rate was gradually decreased and lymphocytic infiltration was found as age increased in 12- and 21-week-old NOD mice, but not 7-week-old NOD mice. Blood vessels were dilated, while endothelial TJ width and paracellular tracer transport were increased in 12-week-old NOD mice. Moreover, the injected CFSE-labeled lymphocytes were observed in SMGs of 12-week-old NOD mice. Claudin-5 level was increased and relocalized from the apical portion of neighboring endothelial cells to lateral membranes and cytoplasm in 12-week-old NOD mice. Additionally, the alteration of claudin-5 expression and distribution was further confirmed in labial salivary glands and bilateral parotid glands from SS patients. In cultured human microvessel endothelial cell line (HMEC-1), IFN-γ stimulation significantly increased claudin-5 expression. Taken together, we identified that the endothelial TJ barrier was disrupted and contributed to the development of salivary hyposecretion and lymphocytic infiltration in SS.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Endothelial tight junction barrier is disrupted in hyposecretory submandibular glands from Sjögren's syndrome mouse model </LI> <LI> The disrupted salivary endothelial barrier is linked with lymphocytic infiltration in Sjögren's syndrome mouse model </LI> <LI> The redistribution of claudin-5 is responsible for disrupted endothelial barrier in salivary glands from Sjögren's syndrome </LI> </UL> </P>

Optimized Mixture Kernels Independent Component Analysis and Echo State Network for Flame Image Recognition

Zhang Li,Zhu Yu-Qin,Yan Xin-Xin,Wu Hao,Li Kun 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.6

In this paper, an optimized mixture kernels independent component analysis and echo state network fl ame image recognition model is proposed. Firstly, in order to describe the fl ame image feature information in detail, 19 feature vectors of the three types of color, shape and texture feature are comprehensively extracted; a mixture kernels independent component analysis method is proposed to perform nonlinear transformation and reduce the correlation of them. The mixture kernels function among them is a combination of linear kernel function, Matérn kernel function and Gaussian radial basis kernel function. Then, the feature vector after nonlinear transformation isused as the input vector, and the echo state network model is trained as the recognition model. At the same time, a normal cloud-black hole optimization algorithm (NCGBH) combining black hole algorithm with cloud model is proposed, which can optimize several adjustable parameters of the model. Four benchmark functions are fi rstly used for simulation experiments to prove advancement of the proposed NCGBH algorithm; and then, several fl ame images are used to verify performance of the proposed recognition model. From the comparison and analysis, it is verifi ed that the proposed method has good results in recognition performance, generalization ability, and computational time.

Abscisic acid synthesis and root water uptake contribute to exogenous methyl jasmonate-induced improved tomato drought resistance

Yan Jiakun,Li Haipeng,Li Yu,Zhang Nan,Zhang Suiqi 한국식물생명공학회 2022 Plant biotechnology reports Vol.16 No.2

In rain-fed semi-arid agricultural areas, unevenly distributed seasonal rainfall influences tomato production. Meanwhile, jasmonic acid, an essential plant hormone, enhances plant resistance to biotic and abiotic stresses; however, its effect on tomato drought resistance remains unclear. In this study, a series of pot experiments were conducted to investigate the effects elicited via addition of exogenous methyl jasmonate (MeJA), an active ingredient of jasmonic acid, on tomato physiology, biochemistry, and transcription under two water conditions. The results indicate that 100 μM MeJA application significantly improved drought resistance in tomato and increased the biomass. Moreover, water deficiency significantly decreased the tomato plant photosynthetic rate, stomatal conductance, and root exudation and increased the leaf abscisic acid (ABA) con- tent. Meanwhile, MeJA application increased root exudation and whole plant transpiration rate to maintain relatively high leaf water content. In leaves, specifically, MeJA increased the expression of carotenoid cleavage dioxygenases and reduced ABA content, which might contribute to the maintenance of a high stomatal conductance. In addition, many genes involved in photosynthetic carbon metabolism and sugar transport were upregulated by MeJA, resulting in a low soluble sugar-to- starch ratio, to maintain plant growth. Collectively, these findings indicate that exogenous MeJA decreases ABA content to maintain high stomatal conductance and enhance root water uptake capacity to maintain improved leaf relative water status, consequently improving tomato drought resistance.

Osteogenic Activities of Genistein Derivatives were Influenced by the Presence of Prenyl Group at Ring A

Zhang, Yan,Li, Xiao-Li,Yao, Xin-Sheng,Wong, Man-Sau 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.12

Our recent report indicated that the crude extract from stem bark of Erythrina variegata L. (Leguminosae) (EV) exerted beneficial effects against osteoporosis induced by estrogen deficiency in vivo. Followup phytochemical study has isolated genistein-derivatives mainly in the form of prenylgenistein from this extract, including 6-prenylgenistein, 8-prenylgenistein, and 6, 8-diprenylgenistein. The present study was performed to investigate the structure-function relationship of these compounds on osteoblastic proliferation, differentiation and mineralization in UMR 106 cells. Our results showed that genistein did not stimulate cell growth while 8-prenylgenistein promoted cell growth significantly by 10$\sim$23%. In contrast, the treatment by 6-prenylgenistein for 48 h reduced UMR 106 cell proliferation when compared to cells treated with genistein. The proliferation of 6,8-diprenylgenistein-treated cells was greater than those treated by 6-prenylgenistein at all testing concentrations. For ALP activity, significant increase was found in cells treated by either 8-prenylgenistein or 6,8-diprenylgenistein for 48 h at the concentration of $10^{-10}M$. In mineralization study, the content of Ca and P in extracellular matrix were significantly increased in 8-prenylgenistein treated cells. The results showed that genistein derivatives isolated from EV demonstrated stimulatory effects on osteogenesis in UMR 106 cells. Based on the study of structure-activity relationship, it appears that prenylation at C-8, but not at C-6, could increase the bone-protective effect of genistein.

Influence of rutin on the effects of neonatal cigarette smoke exposure-induced exacerbated MMP-9 expression, Th17 cytokines and NF-kB/iNOS-mediated inflammatory responses in asthmatic mice model

Li-Li Liu,Yan Zhang,Xiao-Fang Zhang,Fu-Hai Li 대한생리학회-대한약리학회 2018 The Korean Journal of Physiology & Pharmacology Vol.22 No.5

Allergic asthma is one of the most enduring diseases of the airway. The Thelper cells and regulatory T-cells are critically involved in inflammatory responses, mucus hypersecretion, airway remodelling and in airway hyper-responsiveness. Cigarette smoke (CS) has been found to aggravate inflammatory responses in asthma. Though currently employed drugs are effective, associated side effects demand identification and development of novel drugs with negligible or no adverse effects. Rutin, plant-derived flavonoid has been found to possess antioxidant and anti-inflammatory effects. We investigated the ability of rutin to modulate T-cells and inhibit inflammation in experimentally-induced asthma in cigarette smoke exposed mice. Separate groups of neonatal mice were exposed to CS for 10 days from post-natal days 2 to 11. After 2 weeks, the mice were sensitized and challenged with ovalbumin (OVA). Treatment group were given rutin (37.5 or 75 mg/kg body weight) during OVA sensitization and challenge. Rutin treatment was found to significantly inhibit cellular infiltration in the airways and Th2 and Th17 cytokine levels as well. Flow cytometry revealed effectively raised CD4+CD25+Fox3+ Treg cells and supressed Th17 cell population on rutin treatment. Airway hyper-responsiveness observed following CS and OVA challenge were inhibited by rutin. NF-kB and iNOS, chief regulators of inflammatory responses robustly activated by CS and OVA were down-regulated by rutin. Rutin also inhibited the expression of matrix metalloproteinase 9, thereby aiding in prevention of airway remodelling in asthma thereby revealing to be a potent candidate in asthma therapy.