Oxygen-vacancy-rich spinel CoFe2O4 nanocrystals anchored on cage-like carbon for high-performance oxygen electrocatalysis

Yan-Chun Li,Fan-Long Jin,박수진 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.10

We report spinel-type CoFe2O4 nanocrystals (NCs) synthesized through facile hydrothermal growth and their attachment on a cage-like carbon (CC) for efficient and durable oxygen evolution/reduction reaction (OER/ORR) performance. As a catalyst, the so-constructed CoFe2O4 NCs show significantly higher OER performance than bare CoFe2O4 and CC, leading to an overpotential of 1.59 V for the OER at a current density of 10mA/cm. Furthermore, CoFe2O4 NCs on CC electrodes also exhibit good ORR performance, which is comparable to Pt/C, significantly higher than that of bare carbon fiber paper, and acts as a bifunctional electrocatalyst. The CoFe2O4 NCs anchored on the CC electrodes exhibit remarkably long-term stability, which is evaluated by continuous cycling (over 5,000 cycles), without any morphological change, but preserving all the materials within the electrode. The results indicate that the CoFe2O4 NCs have a promising potential for efficient, cost-effective, and durable oxygen electrocatalysis at large scales using earth-abundant materials and low-cost fabrication processes.

Quantification of the Energy Flows during Ultrasonic Wire Bonding under Different Process Parameters

Yangyang Long,Friedrich Schneider,Chun Li,Jörg Hermsdorf,Jens Twiefel,Jörg Wallaschek 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.6 No.3

Despite of its wide and long-term application for interconnections in the field of microelectronics packaging, a quantitative understanding on the mechanisms of ultrasonic (US) wire bonding is still lacked. In this work, the energy flows from the electrical input energy to the different mechanisms during the US bonding process are quantified based on real-time observations via which the relative motions at the wire/substrate and the wire/tool interfaces can be detected. The relative motions at the two interfaces are proved to be caused by both the continuous plastic deformation and the US vibration. The normal force and US power interdependently affect the relative motion amplitudes. The deduced energy flows show that the energy from the transducer mainly flows to the vibration induced friction at the two interfaces and the microwelds formation, deformation and breakage. Despite of their significance to the process, the other mechanisms receive only little amount of energy. The impacts of the process parameters including normal force, US power and time on the energy flows are quantitatively investigated. A good coupling of the normal force and the US power guides more energy to the formation of microwelds while a long process time would increase the friction induced energy consumption.

Heparanase mRNA and Protein Expression Correlates with Clinicopathologic Features of Gastric Cancer Patients: a Meta-analysis

Li, Hai-Long,Gu, Jing,Wu, Jian-Jun,Ma, Chun-Lin,Yang, Ya-Li,Wang, Hu-Ping,Wang, Jing,Wang, Yong,Chen, Che,Wu, Hong-Yan Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.18

Background: Heparanase is believed to be involved in gastric carcinogenesis. However, the clinicopathologic features of gastric cancer with high heparanase expression remain unclear. Aim : The purpose of this study was to comprehensively and quantitatively summarize available evidence for the use of heparanase mRNA and protein expression to evaluate the clinicopathological associations in gastric cancer in Asian patients by meta-analysis. Materials and Methods: Relevant articles listed in MEDLINE, CNKI and the Cochrane Library databases up to MARCH 2015 were searched by use of several keywords in electronic databases. A meta-analysis was performed to clarify the impact of heparanase mRNA and protein on clinicopathological parameters in gastric cancer. Combined ORs with 95%CIs were calculated by Revman 5.0, and publication bias testing was performed by stata12.0. Results: A total of 27 studies which included 3,891 gastric cancer patients were combined in the final analysis. When stratifying the studies by the pathological variables of heparanase mRNA expression, the depth of invasion (633 patients) (OR=4.96; 95% CI=2.38-1.37; P<0.0001), lymph node metastasis (639 patients) (OR=6.22; 95%CI=2.70-14.34, P<0.0001), and lymph node metastasis (383 patients) (OR=6.85; 95% CI=2.04-23.04; P=0.002) were all significant. When stratifying the studies by the pathological variables of heparanase protein expression, this was the case for depth of invasion (1250 patients) (OR=2.76; 95% CI=1.52-5.03; P=0.0009), lymph node metastasis (1178 patients) (OR=4.79 ; 95% CI=3.37-6.80, P<0.00001), tumor size (727 patients) (OR=2.06 ; 95% CI=1.31-3.23; P=0.002) (OR=2.61; 95% CI=2.09-3.27; P=0.000), and TNM stage (1233 patients) (OR=6.85; 95% CI=2.04-23.04; P=0.002). Egger's tests suggested publication bias for depth of invasion, lymph node metastasis, lymph node metastasis and tumor size of heparanase mRNA and protein expression. Conclusions: This meta-analysis suggests that higher heparanase expression in gastric cancer is associated with clinicopathologic features of depth of invasion, lymph node metastasis and TNM stage at mRNA and protein levels, and of tumor size only at the protein level. Egger's tests suggested publication bias for these clinicopathologic features of heparanase mRNA and protein expression, and which may be caused by shortage of relevant studies. As a result, although abundant reports showed heparanase may be associated with clinicopathologic features in gastric cancer, this meta-analysis indicates that more strict studies were needed to evaluate its clinicopathologic significance.

Ginsenoside Rg1 Induces Apoptosis through Inhibition of the EpoR-Mediated JAK2/STAT5 Signalling Pathway in the TF-1/Epo Human Leukemia Cell Line

Li, Jing,Wei, Qiang,Zuo, Guo-Wei,Xia, Jing,You, Zhi-Mei,Li, Chun-Li,Chen, Di-Long Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.6

Ginsenoside Rg1 is one effective anticancer and antioxidant constituent of total saponins of Panax ginseng (TSPG), which has been shown to have various pharmacological effects. Our previous study demonstrated that Rg1 had anti-tumor activity in K562 leukemia cells. The aim of this study was designed to investigate whether Rg1 could induce apoptosis in TF-1/Epo cells and further to explore the underlying molecular mechanisms. Here we found that Rg1 could inhibit TF-1/Epo cell proliferation and induce cell apoptosis in vitro in a concentration and time dependent manner. It also suppressed the expression of EpoR on the surface membrane and inhibited JAK2/STAT5 pathway activity. Rg1 induced up-regulation of Bax, cleaved caspase-3 and C-PAPR protein and down-regulation of Bcl-2 and AG490, a JAK2 specific inhibitor, could enhance the effects of Rg1. Our studies showed that EpoR-mediated JAK2/STAT5 signaling played a key role in Rg1-induced apoptosis in TF-1/Epo cells. These results may provide new insights of Rg1 protective roles in the prevention a nd treatment of leukemia.

국내 뷰티 관련 고등교육 프로그램의 현황 및 교과과정 조사 연구

( Long Chun Li ),안춘순 ( Cheun Soon Ahn ),( Lkhagva Narantuya ),박선화 ( Seon Hwa Park ),조설 ( Xue Zhao ) 한국의류학회 2016 한국의류학회지 Vol.40 No.2

This research investigates the current state of beauty related curriculums and departments of undergraduate and graduate programs in Korea. The results also compared beauty related programs at selected overseas universities. A comprehensive list of 4-year universities with beauty related undergraduate and/or graduate programs were surveyed using the KCUE University Entrance Information (http://www.adiga.kr) site provided by the Korean Council for University Education. Information on the name of the department, curriculum, and year of foundation were obtained from the websites of individual universities. There were 58 universities which have beauty related higher education programs; 43 undergraduate programs, 12 graduate programs, and 40 special graduate programs. The number of special graduate departments were 3.7 times larger than the graduate departments; in addition, 43.9% of the special graduate departments were located in the Seoul/Gyeonggi/Incheon area. The curriculums of beauty related 4-year undergraduate departments were focused on the ‘Beauty care service’ area (50.2%), whereas the curriculums of graduate departments were focused on the ‘Cosmetic science’ area (40.8%). In case of the special graduate programs, there was little difference between the ‘Beauty care service’ area (24.4%) and the ‘Cosmetic science’ area (27.7%). Beauty related programs of overseas universities were mostly focused on cosmetic science with some universities specialized in the marketing aspect.

황백의 품종 및 산지에 따른 면, 견, 양모직물에 대한 염색성 비교

이룡춘 ( Long Chun Li ),안춘순 ( Cheun Soon Ahn ) 한국의류학회 2014 한국의류학회지 Vol.38 No.1

This study examined hwangbek dyeability for cotton, silk, and wool from different tree species and origin as well as their berberine and palmatine content. A total of 12 different hwangbek were examined, six purchased directly from different locations of China and six purchased from the Seoul Medicine Market. Hwangbek purchased from China were 3 Kwanhwangbek (Phellodendron amurense Rupr.) from Jilin, Liaoning, Heilongjiang and 3 Chunhwangbek (Phellodendron chinense Schneid.) from Sichuan, Yunnan, and Guangxi. Hwangbek purchased from the Seoul Medicine Market included 3 hwangbek that originated from Korea and 3 hwangbek imported from China. We extracted 2.5g of each hwangbek into 500mL of water for 60min at 80oC. Dyeing was conducted using the IR dyeing machine for 30min at 55oC using a 1:100 liquor ratio. Cotton was mordanted using tannic acid followed by potassium antimonyl tartrate trihydrate treatment before dyeing. Berberine and palmatine pigments in hwangbek were identified with the HPLC-DAD-MS instrument and the amount of pigment was quantified using an ion chromatogram. The results indicated that the K/S values of dyed fabrics were highly related to the amount of pigment in hwangbek used for dyeing.

Genetic Screening for Mutations in the Chip Gene in Intracranial Aneurysm Patients of Chinese Han Nationality

Su, Li,Zhang, Yuan,Zhang, Chun-Yang,Zhang, An-Long,Mei, Xiao-Long,Zhao, Zhi-Jun,Han, Jian-Guo,Zhao, Li-Jun Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.3

We performed a case-control study to investigate whether SNPs of CHIP might affect the development of IA in Chinese Han nationality. We believe we are the first to have screened IA patients for mutations in the CHIP gene to determine the association with these variants. The study group comprised 224 Chinese Han nationality patients with at least one intracranial aneurysm and 238 unrelated healthy Han nationality controls. Genomic DNA was isolated from blood leukocytes. The entire coding regions of CHIP were genotyped by PCR amplification and DNA sequencing. Differences in genotype and allele frequencies between patients and controls were tested by the chi-square method. Genotype and allele frequencies of the SNP rs116166850 was demonstrated to be in Hardy-Weinberg equilibrium. No significant difference in genotype or allele frequencies between case and control groups was detected at the SNP. Our data do not support the hypothesis of a major role for the CHIP gene in IA development in the Chinese Han population.

海外子公司知识获取决定因素及企业绩效的影响研究

Li, Jing-Xun(李京勋),Kim, Chun-Soo(金春洙),Li, Long-Zhen(李龙,振) 글로벌경영학회 2011 글로벌경영학회지 Vol.8 No.4

近年来, 全球经济环境正日益显现出动态、复杂、不确定性特征, 顺应这一特征, 全球学习能力成为跨国公司赢得竞争优势的关键。全球学习过程主要通过各海外子公司自主灵活的学习, 创造新知识, 并迅速有效地在整个跨国公司内部进行传递与整合来实现。因此, 海外子公司本地知识获取已经构成了跨国公司知识管理的重要组成部分。基于组织学习理论, 本文考察了影响海外子公司知识获取决定因素及本地获取的知识对企业绩效的影响。研究结果表明, 海外子公司的吸收能力和经验多样性对知识获取有正向影响, 但时间经验和网络嵌入性对知识获取没有显著作用。此外, 本土化战略和知识获取绩效评价标准对知识获取有显著影响, 同时海外子公司在本地获取的知识对子公司绩效有显著的正向影响。这些结果表明, 海外子公司自身学习能力和母公司对海外子公司的管理方式是影响知识获取的重要因素, 而海外子公司本地知识获取是跨国公司成功实施国际化战略的一个重要条件。 In recent years, international business scholars have been paying greater attention to MNEs global learning. This study developed an integrated framework, tries to analyze the determinants of knowledge acquisition and its impact on subsidiary performance. Our results show that absorptive capacity and diversity of experience have positive effect on knowledge acquisition, but intensity of experience and network embeddedness have no significant effect. In addition, we also find that localization strategy and subsidiary performance appraisal system stressing the development of new knowledge have positive effect on knowledge acquisition. Lastly, knowledge that acquired host country has positive effect on subsidiary performance. This finding implies that it is necessary to acquire local knowledge for successful internationalization. In conclusion, this study implies that subsidiary’s learning capacity and parent’s management style are important to knowledge acquisition and the extent of knowledge acquisition also important to subsidiary performance.

Application of Block Diagonal Technique to a Hamiltonian Matrix in Performing Spin-splitting Calculations for GaN Wurtzite Materials

Chun-Nan Chen,Sheng-Hsiung Chang,Wei-Long Su,Wan-Tsang Wang,Hsiu-Fen Kao,Jen-Yi Jen,Yiming Li 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.60 No.3

The bulk inversion asymmetry (Dresselhaus) terms (i.e., B2, B1, and B01 terms) of wurtzite materials are determined. The 2 × 2 conduction band, 2 × 2 heavy-hole band, 2 × 2 light-hole band,and 2 × 2 crystal-field split-off hole band matrices of wurtzite semiconductors are developed and decoupled by using a block diagonal technique. Importantly, those 2 × 2 block diagonal matrices incorporate not only the interband coupling effect but also the bulk inversion asymmetry effect. Analytical expressions for the conduction and the valence band spin-splitting parameters and energies of GaN wurtzite materials are formulated by solving the block diagonal matrices. The presence of these terms is shown to include the spin-splitting phenomenon. The bulk inversion asymmetry (Dresselhaus) terms (i.e., B2, B1, and B01 terms) of wurtzite materials are determined. The 2 × 2 conduction band, 2 × 2 heavy-hole band, 2 × 2 light-hole band,and 2 × 2 crystal-field split-off hole band matrices of wurtzite semiconductors are developed and decoupled by using a block diagonal technique. Importantly, those 2 × 2 block diagonal matrices incorporate not only the interband coupling effect but also the bulk inversion asymmetry effect. Analytical expressions for the conduction and the valence band spin-splitting parameters and energies of GaN wurtzite materials are formulated by solving the block diagonal matrices. The presence of these terms is shown to include the spin-splitting phenomenon.

Pre-operative Predictive Factors for Intra-operative Pathological Lymph Node Metastasis in Rectal Cancers

Gao, Chun,Li, Jing-Tao,Fang, Long,Wen, Si-Wei,Zhang, Lei,Zhao, Hong-Chuan Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.11

Background: A number of clinicopathologic factors have been found to be associated with pathological lymph node metastasis (pLNM) in rectal cancer; however, most of them can only be identified by expensive high resolution imaging or obtained after surgical treatment. Just like the Child-Turcotte-Pugh (CTP) and the model for end-stage liver disease (MELD) scores which have been widely used in clinical practice, our study was designed to assess the pre-operative factors which could be obtained easily to predict intra-operative pLNM in rectal cancer. Methods: A cohort of 469 patients who were treated at our hospital in the period from January 2003 to June 2011, and with a pathologically hospital discharge diagnosis of rectal cancer, were included. Clinical, laboratory and pathologic parameters were analyzed. A multivariate unconditional logistic regression model, areas under the curve (AUC), the Kaplan-Meier method (log-rank test) and the Cox regression model were used. Results: Of the 469 patients, 231 were diagnosed with pLNM (49.3%). Four variables were associated with pLNM by multivariate logistic analysis, age<60 yr (OR=1.819; 95% CI, 1.231-2.687; P=0.003), presence of abdominal pain or discomfort (OR=1.637; 95% CI, 1.052-2.547; P=0.029), absence of allergic history (OR=1.879; 95% CI, 1.041-3.392; P=0.036), and direct $bilirubin{\geq}2.60{\mu}mol/L$ (OR=1.540; 95% CI, 1.054-2.250; P=0.026). The combination of all 4 variables had the highest sensitivity (98.7%) for diagnostic performance. In addition, age<60 yr and direct $bilirubin{\geq}2.60{\mu}mol/L$ were found to be associated with prognosis. Conclusion: Age, abdominal pain or discomfort, allergic history and direct bilirubin were associated with pLNM, which may be helpful for preoperative selection.