Synthesis of Uniform Polyaniline Nanosheets and Nanotubes: Dependence of Morphology on the pH

Yumei Zhang,Chengfu Dou,Wenping Wang,Qiang Wang,Ningchuan Feng 한국고분자학회 2016 Macromolecular Research Vol.24 No.8

Polyaniline (PANI) nanomaterials were synthesized by simplified template-free method with ammonium persulfate (APS) as an oxidant. The strong dependence of morphology of polyaniline on the initial pH of the reaction solution has been found. PANI morphology transformed from nanosheets to nanotubes with the decreasing initial pH from 6.70~6.50 to 5.30~5.00, and nanotubes changed further to irregular granules with the decreasing pH lower than 2.26. Polyaniline nanosheets were highly crystalline (2θ=6.2°) but poor in conductivity (5.7×10-5 S/cm) and electroactivity due to low doping level. Though polyaniline nanotubes were poorly crystalline, it had a relative high conductivity (3.4×10-2 S/cm) and maintained the electroactivity in acidic and neutral media which had potential applications in biomedical fields such as tissue engineering and biosensor.

Sub-surface Damage of Ultra-Thin Monocrystalline Silicon Wafer Induced by Dry Polishing

Xundi Zhang,Chenlin Yang,Yumei Zhang,Anmin Hu,Ming Li,Liming Gao,Huiqin Ling,Tao Hang 대한금속·재료학회 2020 ELECTRONIC MATERIALS LETTERS Vol.16 No.4

Ultra-thin wafer fabrication has become a hot spot in recent years with the growing demand for small size and high performance electronic devices. However, far less research focused on the damage behavior in ultra-thin wafer. In this work, 300 mm diameter silicon wafer was thinned to 6 µm thick by grinding plus ultra-precision dry polishing. The damage behavior before and after the dry polishing was discussed. Mechanical and surface analysis showed that the dry polishing process can help improve the strength and surface uniformity of ultra-thin wafer by removing high pressure phase and micro cracks. Series of nano beam diffraction patterns revealed the stress induced by the thinning process only existed in surface. High resolution transmission electron microscopy images analyzed by geometric phase approach indicated that surface dislocations can move across the wafer and reached bottom device layers during the dry polishing, increasing the risk of electrical deterioration. The findings are of great significance to the study on process optimization of ultra-thin wafer and provide insights into the reliability of advanced electronic packaging.

Lignin Based Flexible Electromagnetic Shielding PU Synergized with Graphite

Jia Zhang,Yunxia Qi,Yumei Zhang,Jinchi Duan,Bairun Liu,Baijun Liu,Zhaoyan Sun,Yiquan Xu,Wei Hu,Niaona Zhang 한국섬유공학회 2021 Fibers and polymers Vol.22 No.1

In this paper, lignin (L)-based polyurethane (FeGLPU) with excellent electromagnetic shielding properties wasprepared and studied. The modified reduced iron powder was modified with KH550, and then the obtained modified reducediron powder (Fe) was mixed with lignin, polyethylene glycol 200 (PEG200), hexamethylene diisocyanate (HDI) and graphite(G) to in-situ synthesize the FeGLPU. The thermal stability, mechanical properties, electronic conductivity, and morphologyof the composite FeGLPU were characterized in detail. The electromagnetic interference shielding effectiveness (EMI SE) ofFeGLPU was tested in the frequency range of 8.2-26.5 GHz. When the content of Fe and G was fixed at 10 % and the lignincontent was 5 %, the maximum EMI SE was 21.6 dB, and the frequency width of EMI SE greater than 10 dB was 18.3 GHz. The conductivity was 4.27×10-4 S/m, and the tensile strength of Fe10G10L5PU reached 11.7 MPa. When the lignin contentincreased to be 20 %, the maximum EMI SE was 22.5 dB, and the frequency width of EMI SE greater than 10 dB was18.3 GHz. The conductivity was 1.06×10-2 S/m, and the thermal decomposition temperature T5 (5 % weight loss) reached234 °C. The obtained excellent EMI SE should be due to the synergistic effect of Fe, G and lignin. It can be observed fromthe SEM observation that the G and Fe are uniformly dispersed in PU matrix with strong interfacial interaction. It wasillustrated that the prepared FeGLPU was with efficient electromagnetic shielding properties, good mechanical properties,and high thermal stability. This lignin based electromagnetic shielding PU was proposed to have broad application prospectsdue to its low expenses and ecology friendliness.

Manipulations of glucose/lipid metabolism and gut microbiota of resistant starch encapsulated Ganoderma lucidum spores in T2DM rats

Yumei Jiang,Na Zhang,Yawen Zhou,Zhongkai Zhou,Yu Bai,Padraig Strappe,Chris Blanchard 한국식품과학회 2021 Food Science and Biotechnology Vol.30 No.5

Our team previously demonstrated that Ganodermalucidum spores (GLS) and resistant starch (RS) hadhypoglycemic effects separately on type 2 diabetic mellitus(T2DM) rats. This work was to explore the effects ofadministering encapsulated GLS within RS (referred to asEGLS) in the T2DM rats, which were induced by streptozotocin(STZ). The EGLS was orally administered torats for 28 days. The parameters of glycometabolismand lipometabolism were evaluated, and fecal microbiotacomposition was investigated. The results showed thatEGLS significantly enhanced glycometabolism and lipometabolismparameters in T2DM rats, which might beassociate with the enhancement of the glucose and lipidmetabolism, insulin secretion, and glycogen synthesis andreduced lipogenesis. Furthermore, the intervention ofEGLS also reduced the Proteobacteria community andimproved dysfunctional gut microbiota. This study indicatedEGLS may be a potential candidate for dietaryintervention to modulate diabetes.

Cloning and Characterization of the IgA Fc Receptor from Swine

( Yumei Chen ),( Yunchao Liu ),( Gaiping Zhang ),( Hua Feng ),( Pengchao Ji ),( Guoqiang Wang ),( Chang Liu ),( Yapeng Song ),( Yunfang Su ),( Songlin Qiao ),( Aiping Wang ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.12

The myeloid-specific IgA Fc receptor (FcαR) is a cell surface molecule on immunocytes that provides a fundamental connection between humoral and cellular immunity. In this study, the full-length cDNA sequence of swine FcαRI (swFcαRI) was isolated and characterized and found to contain a 792-base-pair open reading frame, encoding a 264-amino-acid transmembrane glycoprotein with a predicted molecular mass of 29.4 kDa. The swFcαRI shares high amino acid sequence homology (>50%) with its counterparts from cattle, seal, and horse. Rosetting analysis confirmed that COS-7 cells transfected with an swFcαRI expression plasmid was able to combine with chicken erythrocytes sensitized with porcine IgA, but not IgG.

Increased Expression of TGF-β1 in Correlation with Liver Fibrosis during Echinococcus granulosus Infection in Mice

Yumei Liu,Gulizhaer Abudounnasier,Taochun Zhang,Xuelei Liu,Qian Wang,Yi Yan,Jianbing Ding,Hao Wen,Delixiati Yimiti,Xiumin Ma 대한기생충학열대의학회 2016 The Korean Journal of Parasitology Vol.54 No.4

Sciatic nerve leachate of cattle causes neuronal differentiation of PC12 cells via ERK1/2 signaling pathway

Ziqiang Zhang,Yumei Liu,Xuemin Zhu,Lan Wei,Jiamin Zhu,Ke Shi,Guotao Wang,Li Pan 대한수의학회 2018 Journal of Veterinary Science Vol.19 No.4

Previous studies have shown that the sciatic nerve has neurotrophic activity, and nerve regeneration, differentiation, and axon outgrowth can be modulated by different sciatic nerve preparations. However, numerous animals may have to be sacrificed to obtain enough sciatic nerves to make a sciatic nerve preparation. Some studies have demonstrated that the role of sciatic nerve preparations in neural differentiation depends on the neurotrophins that Schwann cells secrete, and these factors are highly conserved among different species. To reduce the use of experimental animals, in this study, we made a leachate by using the sciatic nerve of cattle and explored its effect on neuronal differentiation of rat PC12 cells (a useful model for studying neuronal differentiation). Results showed the neurite outgrowth of PC12 cells treated with the cattle sciatic nerve leachate for 3, 6, and 9 days was significantly improved, and the expressions of β3-tubulin and microtubule-associated protein 2 (two neuron-specific proteins) were increased. Moreover, the ERK1/2 signaling pathway was activated after PC12 cells were incubated with cattle sciatic nerve leachate for 9 days. Thus, a sciatic nerve leachate obtained from cattle can effectively induce neuronal differentiation of rat PC12 cells via ERK1/2 signaling pathway.

Momordicine I alleviates isoproterenol-induced cardiomyocyte hypertrophy through suppression of PLA2G6 and DGK-ζ

Hongming Li,Yumei Qiu,Mengdie Xie,Changsheng Ouyang,Xiaoyun Ding,Hao Zhang,Wei Dong,Yinhua Xiong,Xilan Tang 대한약리학회 2023 The Korean Journal of Physiology & Pharmacology Vol.27 No.1

This study aimed to observe the protective effect of momordicine I, a triterpenoid compound extracted from momordica charantia L., on isoproterenol (ISO)-induced hypertrophy in rat H9c2 cardiomyocytes and investigate its potential mechanism. Treatment with 10 μM ISO induced cardiomyocyte hypertrophy as evidenced by increased cell surface area and protein content as well as pronounced upregulation of fetal genes including atrial natriuretic peptide, β-myosin heavy chain, and α-skeletal actin; however, those responses were markedly attenuated by treatment with 12.5 μg/ml momordicine I. Transcriptome experiment results showed that there were 381 and 447 differentially expressed genes expressed in comparisons of model/control and momordicine I intervention/model, respectively. GO enrichment analysis suggested that the anti-cardiomyocyte hypertrophic effect of momordicine I may be mainly associated with the regulation of metabolic processes. Based on our transcriptome experiment results as well as literature reports, we selected glycerophospholipid metabolizing enzymes group VI phospholipase A2 (PLA2G6) and diacylglycerol kinase ζ (DGK-ζ) as targets to further explore the potential mechanism through which momordicine I inhibited ISO-induced cardiomyocyte hypertrophy. Our results demonstrated that momordicine I inhibited ISO-induced upregulations of mRNA levels and protein expressions of PLA2G6 and DGK-ζ. Collectively, momordicine I alleviated ISO-induced cardiomyocyte hypertrophy, which may be related to its inhibition of the expression of glycerophospholipid metabolizing enzymes PLA2G6 and DGK-ζ.

Silicate Ions Derived from Calcium Silicate Extract Decelerate Ang II-Induced Cardiac Remodeling

Li Xin,Zhang Yanxin,Jin Qishu,Song Qiaoyu,Fan Chen,Jiao Yiren,Yang Chen,Chang Jiang,Dong Zhihong,Que Yumei 한국조직공학과 재생의학회 2023 조직공학과 재생의학 Vol.20 No.5

BACKGROUND: Pathological cardiac hypertrophy is one of the main activators of heart failure. Currently, no drug can completely reverse or inhibit the development of pathological cardiac hypertrophy. To this end, we proposed a silicate ion therapy based on extract derived from calcium silicate (CS) bioceramics for the treatment of angiotensin II (Ang II) induced cardiac hypertrophy. METHODS: In this study, the Ang II induced cardiac hypertrophy mouse model was established, and the silicate ion extract was injected to mice intravenously. The cardiac function was evaluated by using a high-resolution Vevo 3100 small animal ultrasound imaging system. Wheat germ Agglutinin, Fluo4-AM staining and immunofluorescent staining was conducted to assess the cardiac hypertrophy, intracellular calcium and angiogenesis of heart tissue, respectively. RESULTS: The in vitro results showed that silicate ions could inhibit the cell size of cardiomyocytes, reduce cardiac hypertrophic gene expression, including atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and b-myosin heavy chain (b-MHC), decrease the content of intracellular calcium induced by Ang II. In vivo experiments in mice confirmed that intravenous injection of silicate ions could remarkably inhibit the cardiac hypertrophy and promote the formation of capillaries, further alleviating Ang II-induced cardiac function disorder. CONCLUSION: This study demonstrated that the released silicate ions from CS possessed potential value as a novel therapeutic strategy of pathological cardiac hypertrophy, which provided a new insight for clinical trials.

Dark-Blood Computed Tomography Angiography Combined With Deep Learning Reconstruction for Cervical Artery Wall Imaging in Takayasu Arteritis

Su Tong,Zhang Zhe,Chen Yu,Wang Yun,Li Yumei,Xu Min,Wang Jian,Li Jing,Tian Xinping,Jin Zhengyu 대한영상의학회 2024 Korean Journal of Radiology Vol.25 No.4

Objective: To evaluate the image quality of novel dark-blood computed tomography angiography (CTA) imaging combined with deep learning reconstruction (DLR) compared to delayed-phase CTA images with hybrid iterative reconstruction (HIR), to visualize the cervical artery wall in patients with Takayasu arteritis (TAK). Materials and Methods: This prospective study continuously recruited 53 patients with TAK (mean age: 33.8 ± 10.2 years; 49 females) between January and July 2022 who underwent head-neck CTA scans. The arterial- and delayed-phase images were reconstructed using HIR and DLR. Subtracted images of the arterial-phase from the delayed-phase were then added to the original delayed-phase using a denoising filter to generate the final-dark-blood images. Qualitative image quality scores and quantitative parameters were obtained and compared among the three groups of images: Delayed-HIR, Dark-blood-HIR, and Dark-blood-DLR. Results: Compared to Delayed-HIR, Dark-blood-HIR images demonstrated higher qualitative scores in terms of vascular wall visualization and diagnostic confidence index (all P < 0.001). These qualitative scores further improved after applying DLR (Dark-blood-DLR compared to Dark-blood-HIR, all P < 0.001). Dark-blood DLR also showed higher scores for overall image noise than Dark-blood-HIR (P < 0.001). In the quantitative analysis, the contrast-to-noise ratio (CNR) values between the vessel wall and lumen for the bilateral common carotid arteries and brachiocephalic trunk were significantly higher on Darkblood- HIR images than on Delayed-HIR images (all P < 0.05). The CNR values were significantly higher for Dark-blood-DLR than for Dark-blood-HIR in all cervical arteries (all P < 0.001). Conclusion: Compared with Delayed-HIR CTA, the dark-blood method combined with DLR improved CTA image quality and enhanced visualization of the cervical artery wall in patients with TAK.