GRAPHENE AS TUNABLE STATIONARY PHASE ADDITIVE FOR ENANTIOSEPARATION

FEI-YUE TU,LIN-YAN YU,JIN-GANG YU,XIAOQING CHEN,QIANG FU,FEI-PENG JIAO,ZHI-GUANG PENG,TING ZHANG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2013 NANO Vol.8 No.6

Graphene-based biosensor and chiral sensor have made significant progress in recent years. Because of the similarity of the optical enantiomers, enantioseparation is perhaps the most subtle to achieve. Developing more effectively chiral separation techniques based on graphene is highly desirable. Herein, pristine graphene was prepared and then applicated to assist resolution of two racemic drugs of propranolol and ofloxacin using thin-layer chromatography (TLC). In comparison with TLC chiral separation by only using pure D-(-)-tartaric acid as a selector with relatively low degree of separation, a mixture of graphene and D-(-)-tartaric acid is more attractive, efficient and ready available. The high specific resolution ability for racemic compounds aided by graphene might allow its potential application in future chiral separation technologies.

Lnc Tmem235 promotes repair of early steroid-induced osteonecrosis of the femoral head by inhibiting hypoxia-induced apoptosis of BMSCs

Zhang Fei,Peng Wuxun,Wang Tao,Zhang Jian,Dong Wentao,Wang Chuan,Xie Zhihong,Luo Hong,Liu Gang 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Bone marrow mesenchymal stem cells (BMSCs) have been used in the treatment of early steroid-induced osteonecrosis of the femoral head (SONFH). However, the hypoxic microenvironment in the osteonecrotic area leads to hypoxia-induced apoptosis of transplanted BMSCs, which limits their efficacy. Therefore, approaches that inhibit hypoxia-induced apoptosis of BMSCs are promising for augmenting the efficacy of BMSC transplantation. Our present study found that under hypoxia, the expression of the long noncoding RNA (Lnc) transmembrane protein 235 (Tmem235) was downregulated, the expression of Bcl-2-associated X protein was upregulated, the expression of B-cell lymphoma-2 protein was downregulated, and the apoptotic rate of BMSCs was over 70%. However, overexpression of Lnc Tmem235 reversed hypoxia-induced apoptosis of BMSCs and promoted their survival. These results demonstrated that Lnc Tmem235 effectively inhibited hypoxia-induced apoptosis of BMSCs. Mechanistically, we found that Lnc Tmem235 exhibited competitive binding to miR-34a-3p compared with BIRC5 mRNA, which is an inhibitor of apoptosis; this competitive binding relieved the silencing effect of miR-34a-3p on BIRC5 mRNA to ultimately inhibit hypoxia-induced apoptosis of BMSCs by promoting the expression of BIRC5. Furthermore, we cocultured BMSCs overexpressing Lnc Tmem235 with xenogeneic antigen-extracted cancellous bone to construct tissue-engineered bone to repair a model of early SONFH in vivo. The results showed that overexpression of Lnc Tmem235 effectively reduced apoptosis of BMSCs in the hypoxic microenvironment of osteonecrosis and improved the effect of BMSC transplantation. Taken together, our findings show that Lnc Tmem235 inhibited hypoxia-induced apoptosis of BMSCs by regulating the miR-34a-3p/BIRC5 axis, thus improving the transplantation efficacy of BMSCs for treating early SONFH.

Macrophages Promote Coal Tar Pitch Extract-induced Tumorigenesis of BEAS-2B Cells and Tumor Metastasis in Nude Mice Mediated by AP-1

Zhang, Peng,Jin, Yue-Fei,Zhang, Qiao,Wu, Yi-Ming,Wu, Wei-Dong,Yao, Wu,Wu, Yong-Jun,Li, Zhi-Tao,Zhao, Yong,Liu, Yu,Feng, Fei-Fei Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.12

Background: We sought to evaluate the role of tumor associated macrophages (TAMs) on the promotion of coal tar pitch extract (CTPE)-induced tumorigenesis of human bronchial epithelial cells (BEAS-2B) and tumor metastasis in nude mice, and related mechanisms. Materials and Methods: BEAS-2B cells were first treated with 2.4 mg/mL CTPE for 72 hours. After removal of CTPE, the cells were continuously cultured and passaged using trypsin-EDTA. THP-1 cells were used as macrophage-like cells. BEAS-2B cells under different conditions (n=6/group) were injected into the back necks of nude mice, and alterations of tumor xenograft growth, indicative of tumorigenicity, and tumor metastasis were determined. Pathological changes (tumor nests and microvascular lesions) of HE-stained tumor tissues were also evaluated. The expression of AP-1(c-Jun) in xenografts and metastatic tumors was determined using immunohistochemistry. Results: Tumor size and weight in nude mice transplanted with the mixture of CTPE-induced passage 30 BEAS-2B and THP-1 cells (2:1) were increased compared to those from the CTPE-treated BEAS-2B cells at passage 30 alone at different observation time points. Tumor metastasis to lymph nodes and liver was only detected after transplantation of a mixture the two kinds of cells. The numbers of tumor nests and microvascular lesions, and the expression levels of AP-1 (c-Jun) in tumors from the mixture of two kinds of cells were increased apparently in contrast to those in tumor from the CTPE-treated BEAS-2B cells of passage 30 alone. In addition, there was positive correlation between AP-1 (c-Jun) expression level and the number of microvascular lesions, or between AP-1 (c-Jun) expression level and tumor metastasis in these two groups. Conclusions: TAMs not only facilitate tumorigenesis transformation of CTPE-induced BEAS-2B cells, but also promote tumor growth, angiogenesis and metastasis in nude mice in vivo, which may be mediated by AP-1.

Anomalous magnetization jumps in granular Pb superconducting films

Zhang An-Lei,Jiang Wan-Yan,Chen Xing-Hong,Zhang Xiao-Ke,Lu Wen-Lai,Chen Fei,Feng Zhen-Jie,Cao Shi-Xun,Zhang Jin-Cang,Ge Jun-Yi 한국물리학회 2022 Current Applied Physics Vol.35 No.-

In granular superconductors, the grain boundaries are closely related to the vortex dynamics and the macroscopic superconducting properties. In our research, Pb films with different grain sizes were prepared by tuning the substrate temperature. With the grain size decreasing, Pb films are prone to feature the anomalous magnetization jumps in the M − T curves, while in the M − H curves flux avalanche happens. Both phenomena appear in the same region of the H − T phase diagram and thus are considered to have the same origin. The further theoretical analysis shows that with grain size decreasing the pinning mechanism evolves from a mixed δTc and δl pinning to the δl pinning mechanism. The results shed light on the study of pinning mechanism for granular superconductors and is beneficial to the potential application of manipulating vortex pinning by regulation of intrinsic defects.

Risk of Treatment-related Mortality with Sorafenib in Patients with Cancer

Zhang, Xin-Ji,Zhang, Tian-Yi,Yu, Fei-Fei,Wei, Xin,Li, Ye-Sheng,Xu, Feng,Wei, Li-Xin,He, Jia Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.11

Background: Fatal adverse events (FAEs) have been reported with sorafenib, a vascular endothelial growth factor receptor kinase inhibitor (VEGFR TKI). We here performed an up-to-date and detailed meta-analysis to determine the overall risk of FAEs associated with sorafenib. Methods: Databases, including PubMed, Embase and Web of Science, and abstracts presented at the American Society of Clinical Oncology annual meetings were searched to identify relevant studies. Eligible studies included randomized controlled trials evaluating sorafenib effects in patients with all malignancies. Summary incidence rates, relative risks (RRs), and 95% confidence intervals (CIs) were calculated for FAEs. In addition, subgroup analyses were performed according to tumor type and therapy regimen. Results: 13 trials recruiting 5,546 patients were included in our analysis. The overall incidence of FAEs with sorafenib was 1.99% (95%CI, 0.98-4.02%). Patients treated with sorafenib had a significantly increased risk of FAEs compared with patients treated with control medication, with an RR of 1.77 (95%CI 1.25-2.52, P=0.001). Risk varied with tumour type, but appeared independent of therapy regimen. A significantly increased risk of FAEs was observed in patients with lung cancer (RR 2.26; 95% CI 1.03-4.99; P= 0.043) and renal cancer (RR 1.84; 95% CI 1.15-2.94; P= 0.011). The most common causes of FAEs were hemorrhage (8.6%) and thrombus or embolism (4.9%). Conclusions: It is important for health care practitioners to be aware of the risks of FAEs associated with sorafenib, especially in patients with renal and lung cancer.

Soil fungal communities of montane natural secondary forest types in China

Fei Cheng,Xin Wei,Lin Hou,Zhengchun Shang,Xiaobang Peng,Peng Zhao,Zhaoxue Fei,Shuoxin Zhang 한국미생물학회 2015 The journal of microbiology Vol.53 No.6

Distinctive plant communities may provide specific physical and chemical properties with soils by specific litters and root exudates to exert effects on soil microorganisms. Past logging activities in the Qinling Mountains induced diverse natural secondary forest types (NSFTs). How these recovered NSFTs regulate patterns of soil microbial communities remain limited. In the study, we used terminal-restriction fragment length polymorphism (T-RFLP) to precisely determine forest type-specific soil fungal diversity and composition in five NSFTs. Our results indicated that NSFTs had significant impacts on the soil fungal communities. The most diverse fungal species were found in the Armand pine (Pinus armandi) and Chinese pine (Pinus tabulaeformis) forest soils, followed by sharptooth oak (Quercus aliena var. acuteserrata) and Chinese pine-sharptooth oak forest soils, the wilson spruce (Picea wilsonii) forests had the lowest soil fungal diversity. The analyses of community composition suggested that the fungal communities of Armand pine forest soils were similar to those of Chinese pine forest soils, while other communities prominently differed from each other. Stepwise multiple regression analysis revealed that soil silt, clay, pH, and ammonium nitrogen had intimate linkages with soil fungal diversity. Furthermore, the patterns of soil fungal communites were strongly governed by the specific soil environments of the tested NSFTs, as described by canonical correspondence analysis (CCA). Finally, our study showed that soil fungal communities may be mediated by NSFTs via specific soil edaphic status. Hence, such a comparable study may provide fundamental information for fungal diversity and community structure of natural forests and assist with better prediction and understanding how soil fungal composition and function alter with forest type transformation.

Rapid Preparation of Ultrafine BaSO3 by SO2 Storage Material

Fei Zhang,Feng Sha,Xianshu Qiao,Tianxiang Zhao,Bo Guo,Jianbin Zhang 대한화학회 2017 Bulletin of the Korean Chemical Society Vol.38 No.1

In this work, a green and efficient process was developed for the preparation of ultrafine BaSO3 with layered nanostructure surface via the reaction of BaCl2 with a SO2 storage material (SO2SM) at room temperature. The absorption of SO2 with equimolar ethylenediamine (EDA) and ethylene glycol (EG) afforded SO2SM, which not only offered alkyl sulfite but also released EDA and EG that served as efficient surfactants to promote the formation of BaSO3 with spherical morphology and porous structure in the process of synthesis of ultrafine BaSO3. The factors affecting the morphology and size of BaSO3 particle were assessed by investigating the effects of SO2SM concentration, BaCl2 concentration, stirring time and speed. It was found that a higher SO2SM concentration led to a higher degree of supersaturation, and the particle size of BaSO3 could be reduced by increasing SO2SM concentration. Moreover, under the identified optimal reaction conditions, ultrafine BaSO3 was obtained with an average diameter of 450 nm. In addition, a plausible formation process of BaSO3 was proposed to explain the observed reaction results. Overall, the developed process in this work provides an efficient method for the capture, utilization, and conversion of SO2 into a valuable chemical.

Adjustable and extensible hexagonal acoustic metamaterial cell combining multiple parallel Helmholtz resonators with optional apertures

Fei Yang,Shaohua Bi,Xinmin Shen,Xiaocui Yang,Xinqing Wang,Xiangpo Zhang,Jinhong Xue,Xiaonan Zhang,Qin Yin,Juying Dai,Wenqiang Peng,Jingwei Zhu,Junhong Ren 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.12

To prevent noise pollution, a hexagonal acoustic metamaterial cell combining multiple parallel Helmholtz resonators with optional apertures is proposed. There were 6 trapezoidal chambers and 6 triangular chambers, and each front panel had 6 different apertures, which meant that there were 6 12 = 2176782336 possible permutations. The distribution of sound pressures obtained by acoustic finite element simulation revealed the acoustic absorption mechanism, which provided effective guidance to alter the absorption capacity. For certain scenarios, the acoustic absorption performance was optimized by the joint combination of artificial neural network and acoustic finite element simulation. Through manufacturing and testing the sample, actual average acoustic absorption coefficients were achieved at 0.6733, 0.7296, 0.8785 and 0.7065 for the target frequency ranges 350-950 Hz, 400-1000 Hz, 500-800 Hz and 350-700 Hz, respectively, with total thickness 40 mm. The tunable acoustic absorption property proved that the hexagonal acoustic metamaterial cell was appropriate for noise reduction with variable frequency ranges.

Synthesis and Properties of Arylacetylene Resins with Siloxane Units

Fei Gao,Lingling Zhang,Lemin Tang,Jian Zhang,Yan Zhou,Farong Huang,Lei Du 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.4

A series of arylacetylene resins with siloxane units were synthesized by the condensation reactions of m-diethynylbenzene magnesium reagents with various α,ω-bis(chloro)dimethylsiloxanes. These resins are liquids and are miscible with common organic solvents at room temperature. The structures of the resins were characterized by FT-IR, 1H NMR,13C NMR, 29Si NMR, and gel permeation chromatography (GPC). The thermal behaviors of the resins were examined with differential scanning calorimetry (DSC). These resins have good processability. They can be thermally crosslinked through the ethynyl groups to produce cured resins. The thermal and thermooxidative stabilities of the cured resins were studied by thermogravimetric analysis (TGA). The cured resins possess high thermal and thermooxidative stability. Their decomposition occurs at above 500 oC in both N2 and air. With increasing the length of siloxane units in the resins, the thermal stability of the cured resins decreases in N2. When the cured resins were sintered above 1450 oC under argon, hard and glassy SiOC ceramics were obtained. These SiOC ceramics have the decomposition temperatures at 5% weight loss above 800 oC in air.

Design and Implementation of Web Crawler with Real-Time Keyword Extraction based on the RAKE Algorithm

( Fei Zhang ),( Sunggyun Jang ),( Inwhee Joe ) 한국정보처리학회 2017 한국정보처리학회 학술대회논문집 Vol.24 No.2

We propose a web crawler system with keyword extraction function in this paper. Researches on the keyword extraction in existing text mining are mostly based on databases which have already been grabbed by documents or corpora, but the purpose of this paper is to establish a realtime keyword extraction system which can extract the keywords of the corresponding text and store them into the database together while grasping the text of the web page. In this paper, we design and implement a crawler combining RAKE keyword extraction algorithm. It can extract keywords from the corresponding content while grasping the content of web page. As a result, the performance of the RAKE algorithm is improved by increasing the weight of the important features (such as the noun appearing in the title). The experimental results show that this method is superior to the existing method and it can extract keywords satisfactorily.