A General Self-Propagating High-Temperature Synthesis Method for Fast and Easy Preparation of Metal Oxide Nanostructures from Low Melting Point Metals

Nian Liu,Guodong Zhang,Yadong Xiao,Zhifang Peng 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2015 NANO Vol.10 No.1

Different metal oxide nanostructures including SnO2 nanowires, SnO2 nanoparticles, ZnO nanorods, ZnO nanoparticles, Al2O3 nanoparticles, SiO2 nanoarray, and SnO2–SiO2 core–shell nanoparticles, can be selectively synthesized by Self-propagating High-temperature Synthesis (SHS) method with different reaction systems. This method can be easily applied to synthesize metal oxide nanostructures with high yield and excellent purity from low melting point metals in a very short time at low cost without the need for any sophisticated equipment. The composition of reaction system has a crucial influence on the reaction temperature and morphology of the end products. Compared with nanoparticles, nanowires or nanorods can be obtained at lower reaction temperature. And introducing the chemical containing silicon to the reaction system allows the formation of SiO2 nanoarray and SnO2–SiO2 core–shell nanoparticles.

Autogenous Shrinkage and Crack Resistance of Carbon Nanotubes Reinforced Cement‑Based Materials

Yanming Liu,Tao Shi,Yujing Zhao,Yuan Gu,Zhifang Zhao,Jiabin Chen,Bingmiao Zheng,Shichong Shi 한국콘크리트학회 2020 International Journal of Concrete Structures and M Vol.14 No.5

Cracking caused by shrinkage deformation of cement-based materials at early age is a major problem leading to material failure in restrained conditions. Carbon nanotubes (CNTs) are incorporated into cement-based materials, and the autogenous shrinkage and crack resistance of the new composite materials obtained by linear shrinkage and ring tests are studied to solve the destruction of the materials caused by the shrinkage of cement-based materials. The results showed that addition of CNTs significantly inhibited the autogenous shrinkage of cement-based materials with maximum reduction rate above 40%. CNTs also significantly improved the cracking resistance of cement-based materials. The optimal effect was noticed at CNTs content of 0.1 wt%. The incorporation of CNTs not only inhibits the autogenous shrinkage of cement-based materials, but also inhibits the drying shrinkage of cement-based materials to some extent. Therefore, carbon nanotubes have the potential to solve the destruction of materials caused by shrinkage of cement-based materials.

Cosmogenic nuclides (10Be and 26Al) erosion rate constraints in the Badain Jaran Desert, northwest China: implications for surface erosion mechanisms and landform evolution

Tong Zhao,Wenjing Liu,Zhifang Xu,Taoze Liu,Sheng Xu,Lifeng Cui,Chao Shi 한국지질과학협의회 2019 Geosciences Journal Vol.23 No.1

Both tectonics and climate affect surface erosion and change the landform. Long-term surface erosion rates determined by in situ produced cosmogenic nuclides are useful quantitative constraints for landform evolution in geological time scale. Measurements of cosmogenic 10Be and 26Al in the granitic rocks exposed in the Badain Jaran Desert, give a mean erosion rate of 7.3 ± 2.6 m/Ma, which is an order of magnitude higher than those reported in other extremely arid regions. Tectonic activity is supposed to be the first order control on regional erosion rate by comparing the 10Be erosion rates of arid regions with different precipitation ranges and tectonic activities worldwide. However the higher erosion rates in the Badain Jaran Desert compared with other arid regions within the stable tectonic background were attributed to the wind erosion and periodically warmer and wetter climate since late Pleistocene. Besides, the estimated eroded mass flux of 7.8 × 104 t/y suggests that erosion products of bedrocks in the Badian Jaran Desert only contribute minor desert deposits, which indicates massive exogenous materials input to the desert.

Detection of Myocardial Metabolic Abnormalities by 18F-FDG PET/CT and Corresponding Pathological Changes in Beagles with Local Heart Irradiation

Rui Yan,Jianbo Song,Zhifang Wu,Min Guo,Jianzhong Liu,Jianguo Li,Xinzhong Hao,Sijin Li 대한영상의학회 2015 Korean Journal of Radiology Vol.16 No.4

To determine the efficacy of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in the detection of radiation-induced myocardial damage in beagles by comparing two pre-scan preparation protocols as well as to determine the correlation between abnormal myocardial FDG uptake and pathological findings. The anterior myocardium of 12 beagles received radiotherapy locally with a single X-ray dose of 20 Gy. 18F-FDG cardiac PET/CT was performed at baseline and 3 months after radiation. Twelve beagles underwent two protocols before PET/CT: 12 hours of fasting (12H-F), 12H-F followed by a high-fat diet (F-HFD). Regions of interest were drawn on the irradiation and the non-irradiation fields to obtain their maximal standardized uptake values (SUVmax). Then the ratio of the SUV of the irradiation to the non-irradiation fields (INR) was computed. Histopathological changes were identified by light and electron microscopy. Using the 12H-F protocol, the average INRs were 1.18 ± 0.10 and 1.41 ± 0.18 before and after irradiation, respectively (p = 0.021). Using the F-HFD protocol, the average INRs were 0.99 ± 0.15 and 2.54 ± 0.43, respectively (p < 0.001). High FDG uptake in irradiation field was detected in 33.3% (4/12) of 12H-F protocol and 83.3% (10/12) of F-HFD protocol in visual analysis, respectively (p = 0.031). The pathology of the irradiated myocardium showed obvious perivascular fibrosis and changes in mitochondrial vacuoles. High FDG uptake in an irradiated field may be related with radiation-induced myocardial damage resulting from microvascular damage and mitochondrial injury. An F-HFD preparation protocol used before obtaining PET/CT can improve the sensitivity of the detection of cardiotoxicity associated with radiotherapy.

Analysis on Self-breakdown Statistics Properties for a Spark Switch

Mo, Chen,Guofu, Li,Qinxiao, Dong,Zhifang, Liu,Zhiyuan, Li 대한전기학회 2014 The Journal of International Council on Electrical Vol.4 No.2

According to the working characteristics of over-voltage protective device for series compensation, the principle and structure of spark switch were introduced in this paper briefly. Special test loop and HV fast switch-off device were designed to evaluate the performance of spark swich in trials. Test data and mathematic statistic results revealed that the self-breakdown probability of spark switch obeyed the normal distribution and the cumulative distribution of spark switch self-breakdown had been less affected by different enviroment temperature. The number of trials was restricted to the characteristics of insulated gas and the electrode surface state in the practical application. Reasonable choice of test number can keep estimation error at a relatively low level, particularly for parameter estimation by using small sample of self-breakdown voltage. The conclusion is instructive to the development and engineering application of spark switch for over-voltage protective equipment of series compensation.

Anterior Gradient 3 Promotes Breast Cancer Development and Chemotherapy Response

Qiao Xu,Ying Shao,Jinman Zhang,Huikun Zhang,Yawen Zhao,Xiaoli Liu,Zhifang Guo,Wei Chong,Feng Gu,Yongjie Ma 대한암학회 2020 Cancer Research and Treatment Vol.52 No.1

Purpose Anterior gradient 3 (AGR3) belongs to human anterior gradient (AGR) family. The function of AGR3 on cancer remains unknown. This research aimed to investigate if AGR3 had prognostic values in invasive ductal carcinoma (IDC) of breast cancer and could promote tumor progression. Materials and Methods AGR3 expression was detected in breast benign lesions, ductal carcinoma in situ and IDC by immunohistochemistry analysis. AGR3’s correlations with clinicopathological features and prognosis of IDC patients were analyzed. By cell function experiments, collagen gel droplet-embedded culture drug sensitivity test and cytotoxic analysis, AGR3’s impacts on proliferation, invasion ability, and chemotherapeutic drug sensitivity of breast cancer cells were also detected. Results AGR3 was up-regulated in luminal subtype of histological grade I-II of IDC patients and positively correlated with high risks of recurrence and distant metastasis. AGR3 high expression could lead to bone or liver metastasis and predict poor prognosis of luminal B. In cell lines, AGR3 could promote proliferation and invasion ability of breast cancer cells which were consistent with clinical analysis. Besides, AGR3 could indicate poor prognosis of breast cancer patients treated with taxane but a favorable prognosis with 5-fluoropyrimidines. And breast cancer cells with AGR3 high expression were resistant to taxane but sensitive to 5-fluoropyrimidines. Conclusion AGR3 might be a potential prognostic indicator in luminal B subtype of IDC patients of histological grade I-II. And patients with AGR3 high expression should be treated with chemotherapy regimens consisting of 5-fluoropyrimidines but no taxane.

Identification of S-Nitrosylation of Proteins of Helicobacter pylori in Response to Nitric Oxide Stress

Wei Qu,Yabin Zhou,Yundong Sun,Ming Fang,Han Yu,Wenjuan Li,Zhifang Liu,Jiping Zeng,Chunyan Chen,Chengjiang Gao,Jihui Jia 한국미생물학회 2011 The journal of microbiology Vol.49 No.2

Innate and adaptive immune responses are activated in humans when Helicobacter pylori invades the gastric mucosa. Nitric oxide (NO) and reactive nitrogen species are important immune effectors, which can exert their functions through oxidation and S-nitrosylation of proteins. S-nitrosoglutathione and sodium nitroprusside were used as NO donors and H. pylori cells were incubated with these compounds to analyze the inhibitory effect of NO. The suppressing effect of NO on H. pylori has been shown in vitro. Furthermore,the proteins modified by S-nitrosylation in H. pylori were identified through the biotin switch method in association with matrix-assisted laser desorption ionization/time-of-flight tandem mass spectrometry (MALDITOF-MS/MS). Five S-nitrosylated proteins identified were a chaperone and heat-shock protein (GroEL),alkyl hydroperoxide reductase (TsaA), urease alpha subunit (UreA), HP0721, and HP0129. Importantly,S-nitrosylation of TsaA and UreA were confirmed using purified recombinant proteins. Considering the importance of these enzymes in antioxidant defenses, adherence, and colonization, NO may exert its antibacterial actions by targeting enzymes through S-nitrosylation. Identification of protein S-nitrosylation may contribute to an understanding of the antibacterial actions of NO. Our findings provide an insight into potential targets for the development of novel therapeutic agents against H. pylori infection.