Biodegradable cross-linked poly(L-lactide-co-e-caprolactone) networks for ureteral stent formed by gamma irradiation under vacuum

Xiliang Liu,Song Liu,Youkun Fan,Jin Qi,Xin Wang,Wei Bai,Dongliang Chen,Chengdong Xiong,Lifang Zhang 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.104 No.-

The poly(L-lactide-co-e-caprolactone) (PLCL) ureteral stent creeps and loses shape stability, increasingthe risk of stent tube dislocation. The rubbery biodegradable cross-linked PLCL networks were preparedthrough gamma irradiation under vacuum in the presence of trimethylolpropane triacrylate (TMPTA),pentaerythritol tetraacrylate (PET4A), and pentaerythritol triacrylate (PETA). At a standard sterilizationdose of 25 kGy, the gel content and network density of PLCL networks increased with increasingcrosslinking agent content (1, 3, 5, 7 wt%), and crosslinking efficiency decreased in the order ofPETA > PET4A > TMPTA. The average molecular weight (Mc ) between two crosslinks ranged from 2000to 105 g/mol. To perform the beneficial semi-interpenetrated polymer network and characterized bythe principle, the networks were processed in several doses (25, 50, 75, 100, and 125 kGy). In place ofthe Charlesby-Pinner equation, the irradiation cross-linking followed the Chen-Liu-Tang equation. ThePLCL network with 7 wt% PETA had a gel fraction of 83%, tensile strength of 34.7 MPa, and tensile setvalue as low as 5%. Furthermore, degradation in vitro was slowed down. Thus, PLCL networks with appropriateelasticity and flexibility, inherent biodegradability, and excellent biocompatibility can provide apromising alternative method for soft tissue repair engineering, such as ureteral stents.

AtHAP3b Plays a Crucial Role in the Regulation of Flowering Time in Arabidopsis during Osmotic Stress

Chen, Nai-Zhi,Zhang, Xiu-Qing,Wei, Peng-Cheng,Chen, Qi-Jun,Ren, Fei,Chen, Jia,Wang, Xue-Chen Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.6

The HAP complex has been found in many eukaryotic organisms. HAP recognizes the CCAAT box present in the promoters of 30% of all eukaryotic genes. The HAP complex consists of three subunits - HAP2, HAP3 and HAP5. In this paper, we report the biological function of the AtHAP3b gene that encodes one of the HAP3 subunits in Arabidopsis. Compared with wild-type plants, hap3b-1 and hap3b-2 mutants exhibited a delayed flowering time under long-day photoperiod conditions. Moreover, the transcription levels of FT were substantially lower in the mutants than in the wild-type plants. These results imply that AtHAP3b may function in the control of flowering time by regulating the expression of FT in Arabidopsis. In a subsequent study, AtHAP3b was found to be induced by osmotic stress. Under osmotic stress conditions, the hap3b- 1 and hap3b-2 mutants flowered considerably later than the wild-type plants. These results suggest that the AtHAP3b gene plays more important roles in the control of flowering under osmotic stress in Arabidopsis.

Extracorporeal Shock Wave Combined with Teriparatide-Loaded Hydrogel Injection Promotes Segmental Bone Defects Healing in Osteoporosis

Chen Qi,Xia Chen,Shi Binbin,Chen Chuyong,Yang Chen,Mao Guangfeng,Shi Fangfang 한국조직공학과 재생의학회 2021 조직공학과 재생의학 Vol.18 No.6

BACKGROUND: Osteoporosis is a systemic bone disease characterized by decreased bone density and deterioration of bone microstructure, leading to an increased probability of fragility fractures. Once segmental bone defect occurs, it is easy to cause delayed union and nonunion. METHODS: The aim of this study is to investigate the efficacy of extracorporeal shock wave (ESW) and teriparatide-loaded hydrogel (T-Gel) combined strategy on the cell activity and differentiation of osteoporosis derived bone marrow mesenchymal stem cells (OP-BMSCs) in vitro and bone regeneration in osteoporotic segmental bone defects in vivo. RESULTS: In vitro, the strategy of combining ESW and T-Gel significantly enhanced OP-BMSCs proliferation, survival, migration, and osteogenic differentiation by up-regulating the alkaline phosphatase activity, mineralization, and expression of runt-related transcription factor-2, type I collagen, osteocalcin, and osteopontin. In the segmental bone defect models of osteoporotic rabbits, Micro-CT evaluation and histological observation demonstrated this ESW-combined with T-Gel injection significantly induced bone healing by enhancing the osteogenic activity of the local microenvironment in osteoporotic defects. CONCLUSION: In conclusion, ESW-combined with T-Gel injection could regulate the poor osteogenic microenvironment in osteoporotic defects and show potential for enhancing fragility fractures healing. BACKGROUND: Osteoporosis is a systemic bone disease characterized by decreased bone density and deterioration of bone microstructure, leading to an increased probability of fragility fractures. Once segmental bone defect occurs, it is easy to cause delayed union and nonunion. METHODS: The aim of this study is to investigate the efficacy of extracorporeal shock wave (ESW) and teriparatide-loaded hydrogel (T-Gel) combined strategy on the cell activity and differentiation of osteoporosis derived bone marrow mesenchymal stem cells (OP-BMSCs) in vitro and bone regeneration in osteoporotic segmental bone defects in vivo. RESULTS: In vitro, the strategy of combining ESW and T-Gel significantly enhanced OP-BMSCs proliferation, survival, migration, and osteogenic differentiation by up-regulating the alkaline phosphatase activity, mineralization, and expression of runt-related transcription factor-2, type I collagen, osteocalcin, and osteopontin. In the segmental bone defect models of osteoporotic rabbits, Micro-CT evaluation and histological observation demonstrated this ESW-combined with T-Gel injection significantly induced bone healing by enhancing the osteogenic activity of the local microenvironment in osteoporotic defects. CONCLUSION: In conclusion, ESW-combined with T-Gel injection could regulate the poor osteogenic microenvironment in osteoporotic defects and show potential for enhancing fragility fractures healing.

Kinetics of Nitrogen Absorption in Molten AISI 316 Stainless Steel During Immersion Nitrogen Blowing

Chen Jian-Bin,Chen Qi-Zhong,Chen Zhao-Ping,Jiang Zhou-Hua,Huang Zong-Ze,Pan Jia-Qi 대한금속·재료학회 2012 METALS AND MATERIALS International Vol.18 No.1

Nitrogen absorption in molten metal for stainless steel AISI316 has been investigated by immersion nitrogen blowing through an immersed alumina nozzle with an internal diameter of 3 mm. Based on these experimental data, some kinetic parameters of nitrogen absorption, such as reaction order, rate constant and apparent activation energy of nitrogen absorption reaction, have been obtained. Effect of stirring by immersion nitrogen blowing through an immersed alumina nozzle on nitrogen absorption reaction has been observed. Results show the following: (1) Nitrogen absorption reaction is the −1.5th order reaction. The rate constant N is of the order of 10−5wt%2.5·min −1. Nitrogen absorption reaction for AISI 316 has negative apparent activation energy of −92.40 kJ·mol −1. This indicates that the nitrogen absorption reaction has a complex and multistep reaction mechanism. (2) The rate of nitrogen absorption reaction in molten stainless steel is mixture control by the adsorption of monatomic nitrogen on the surface of molten stainless steel and mass transfer in molten metal. (3) A rate equation of nitrogen absorption reaction has been derived based on a mixed control mechanism by both the -1st order nitrogen absorption reaction and mass transfer in molten metal.

AtHAP3b Plays a Crucial Role in the Regulation of Flowering Time in Arabidopsis during Osmotic Stress

Nai Zhi Chen,Xiu Qing Zhang,Peng Cheng Wei,Qi Jun Chen,Fei Ren,Jia Chen,Xue Chen Wang 한국생화학분자생물학회 (구 한국생화학회) 2007 BMB Reports Vol.40 No.6

Conjugated linoleic acid (CLA) regulates female reproduction via sex pheromone regulation without affecting larval development in Drosophila melanogaster

Phoebe B. Chen(Phoebe B. Chen),Lynnea Young(Lynnea Young),Ju Hyeon Kim(Ju Hyeon Kim),Weipeng Qi(Weipeng Qi),John M. Clark(John M. Clark),Yeonhwa Park(Yeonhwa Park) 한국축산식품학회 2020 Food and Life Vol.2020 No.1

Knowledge on the potential role of conjugated linoleic acid (CLA) on reproduction and development is currently limited. Therefore, the goal of the current study was to determine the effects of CLA on reproduction and development using the Drosophila model. In this study, adult and larva Drosophila melanogaster were fed fly food with 0.5% water (blank), CLA (50:50 of cis-9, trans-11 and trans-10, cis-12 CLA isomers in triglyceride form) or safflower oil (69% linoleic acid, LA, as control) to examine the effects of CLA on fecundity, sex pheromones, transcription level of oogenesis, larval body composition, and eclosion time. CLA-treated females had lowered brood size without changes in hatchability, along with decreased 7,11-heptacosadiene and 7,11-nonacosadiene, the principle female pheromones, when compared to LA and blank. Moreover, CLA reduced transcription level of lipid storage droplet-2 (lsd-2) compared to LA. CLA did not influence larval composition nor eclosion time. In conclusion, CLA inhibited reproduction capability in D. melanogaster in part via reduced fatty acid-derived signaling pheromone and oogenesis modulations. As key biological processes are conserved between humans and flies, knowledge from this research may provide valuable insight into reproduction and development responses to CLA.

The Impact of Home and Host Country Institutions on the Exit of Chinese Foreign Subsidiaries

Qi Chen,한병섭 한국무역연구원 2020 무역연구 Vol.16 No.5

Purpose This study aims to examine the impact of host country institutions on the exit of foreign subsidiaries, and tries to figure out how the home country institutions moderate the relationship between host country institutions and subsidiary exit. Design/Methodology/Approach The sample of this study includes 7,098 foreign subunits established by 2,401 Chinese listed manufacturing firms in 121 countries. This study used Logit Regression to measure the effect of home and host country institutions on the exit of foreign subsidiaries. Findings The results show that when entering countries with better institutional profile than China, the host country institutions negatively affect the exit of Chinese foreign subsidiaries and home country institutions have positive moderating effect. While, when entering countries with worse institutional profile than China, the host country institutions positively affect the exit of Chinese foreign subsidiaries and home country institutions have no moderating effect. Research Implications This study makes a new attempt to empirically examines the moderating effect of home country institutions on foreign subsidiary’s exit decision while being subject to the host country institutions, which helps fill the gap in this area. Moreover, this study offers a certain understanding of the impact of both home and host country institutions on the survival of foreign subsidiaries in host countries, which may be helpful for future policy development and firms’ internationalization strategy development.

Genetic variations in the bitter taste receptor gene TAS2R38 are related to cigarette smoking behavior in Han Chinese smokers

Qi Fei-Yan,Zhu Zhou-Hai,Li Meng,Guan Ying,Peng Qi-Yuan,Lu She-Ming,Liu Zhi-Hua,Wang Ming-Feng,Miao Ming-Ming,Chen Zhang-Yu,Li Xue-Mei,Bai Jie,Yao Jian-Hua 한국유전학회 2022 Genes & Genomics Vol.44 No.11

Background: Smoking behavior is influenced by multiple genes, including the bitter taste gene TAS2R38. It has been reported that the correlation between TAS2R38 and smoking behavior has ethnicity-based differences. However, the TAS2R38 status in Chinese smokers is still unclear. Objective: This study aims to investigate the possible relationship between genetic variations in TAS2R38 (A49P, V262A and I296V) and smoking behaviors in the Han Chinese population. Methods: The haplotype analyses were performed and smoking behavior questionnaire was completed by 1271 individuals. Genetic association analyses for smoking behavior were analyzed using chi-square test. Further, for investigating the molecular mechanism of TAS2R38 variants effect on smoking behavior, we conducted TAS2R38-PAV and TAS2R38-AVI expression plasmids and tested the cellular calcium assay by cigarette smoke compounds stimulus in HEK293. Results: Significant associations of genetic variants within TAS2R38 were identified with smoking behavior. We found a higher PAV/PAV frequency than AVI/AVI in moderate and high nicotine dependence (FTND ≥ 4; X2 = 4.611, 1 df, p = 0.032) and strong cigarette smoke flavor intensity preference (X2 = 4.5383, 1 df, p = 0.033) in participants. Furthermore, in the in vitro cellular calcium assay, total particle matter (TPM), N-formylnornicotine and cotinine, existing in cigarette smoke, activated TAS2R38-PAV but not TAS2R38-AVI-transfected cells. Conclusion: Our data highlights that genetic variations in TAS2R38 are related to smoking behavior, especially nicotine dependence and cigarette smoke flavor intensity preference. Our findings may encourage further consideration of the taste process to identify individuals susceptible to nicotine dependence, particularly Han Chinese smokers.

The Tacit Knowledge of Media Communication to University Sport and Global Education Developments

( Qi Yue Chen ) 한국체육학회 2015 국제스포츠과학 학술대회 Vol.2015 No.1

Purpose: Tacit knowledge is contained in physical education teaching contents and media communication, carried by students, embodied in sports skills. This study analyzes the influence on university students` humanistic literacy during the process of media communication in the perspective of Communication Study, and takes an example of commentary and reports of classical Beijing Olympic shooting(Emmons) to explore the containing education function. Method: It mainly uses the four research methods of literature, case, questionnaires and logical analysis. Through a random survey on 200 university students in The Capital University of Physical Education and Sports, Peking University, Communication University of China, The Beijing Second Language Institute, the related data are obtained that provides the data are obtained that provides the data protection for the research. Result: In the activities of the dissemination and commentary, the some audience`s psychological needs should be corresponded and unified with the fresh, fun, proximity, time and humane owned by news facts and news itself, which constitutes the value performance of sports live commentary and reports. The achievement of education role of media and communication is mainly reflected in three progressive levels of "Emotional Appearance", "Emotion Touch" and "Emotional Thought". Take an example of "Emmons`s last shot of 4.4 Ring, so championship changed hands and history repeated itself to analyze its emotional grasping and education functions in the sports commentary and reports. The results show that the cultivation of humanistic literacy and the tactile effect of subtle media influence are much greater than the theoretical sermon. The university students` humanistic literacy is mainly expressed in the aspects of ideal pursuit, aesthetic taste,value orientation and others. The spread of media has an important revelation for students` education of humanistic literacy. Conclusion: Firstly, for university students the education should combine reason and feelings, while the tactile effect of feeling and learning is stronger than sermon, and this subtle influence of education function is immeasurable. Secondly, Tacit knowledge`s transfer in media communication mainly includes such two forms as "apprentice system" and the "explicit transformation" of tacit knowledge. Thirdly, universities need to focus on students` humanistic literacy,while it must firstly cultivate university students to have harmonious development for a sound personality, mentality and physique. Fourth, guide students how to properly treat a variety of pros and grow and obtain the experience from failure. Fifth, when encouraging faster,stronger and higher Olympic spirit, it should pay attention to the grasp and interpretation of human nature. This will promote the quality education that bothers the students education for long term and promote the education process that uses "felling" to influence people.

The Consumer Behavior Study of Rural Tourism Based on Psychological Contract

CHEN QI(陈琦) 세계문화관광학회 2011 Conference Proceedings Vol.12 No.-

Along with the theory of psychological contract ripening and developing it has begun to be concerned about in the field of marketing. With the different of marketing situation and research groups the content and structure characteristics of psychological contract will be differences. Rural tourism market as a complex and large whole is composed by different tourism consumer and groups. This paper defines the concept of rural tourism consumer's psychological contract combining the marketing situation of rural tourism. On the base of the analyzing internal mechanism about psychological contract and customer behaviour of rural tourism consumer this paper puts forward the whole management ideas of psychological contract of rural tourism consumer behaviour including creating management of psychological contract of rural tourism consumer behaviour dynamic management of psychological contract of rural tourism consumer behavior and breach management of psychological contract of rural tourism consumer behaviour. 随着心理契约理论的成熟和发展 营销学领域心理契约行为的研究开始受到关注.由于营销情境 和消费群体的不同 心理契约的内容和结构特点也会有所差异.乡村旅游作为一个复杂而庞大的整体 由不同的旅游消费者和群体组成.本文对乡村旅游消费的心理契约概念进行界定 在分析乡村旅游消费 的心理契约与消费行为的内在机制的基础上 提出乡村旅游消费行为心理契约全程管理的理念 包括乡村旅游消费行为心理契约的创建管理, 乡村旅游消费行为心理契约的动态管理以及乡村旅游消费行为心理契约的违背管理.