Effects of Temperature, Illumination, and Sodium Ascorbate on Browning of Green Tea Infusion

Qian Ye,Hao Chen,Lin Bin Zhang,Jian Hui Ye,Jian Liang Lu,Yue Rong Liang 한국식품과학회 2009 Food Science and Biotechnology Vol.18 No.4

Browning of tea infusion is an obstructive factor influencing shelf life of ready-to-drink green tea. Effects of temperature and illumination on the browning of green tea infusion were investigated. It was shown that both elevated temperature and illumination led to the browning of green tea infusion, but temperature had greater effect on infusion color and level of catechins than illumination. The levels of unoxidized catechins such as (-)-epigallocatechin gallate (EGCg), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECg), (-)-epicatechin (EC), and total catechins remaining in the tea infusion were significantly correlated to color parameters of the tea infusion. Sodium ascorbate inhibited the infusion browning by suppressing the oxidation of tea catechins and it is considered to be a more suitable preservative for prolonging shelf life of ready-to-drink green tea than ascorbic acid because it has less effect on tea taste. The effects of temperature and illumination on the epimerization of catechins were also discussed.

Tristetraprolin Overexpression in Gastric Cancer Cells Suppresses PD-L1 Expression and Inhibits Tumor Progression by Enhancing Antitumor Immunity

Jian Guo,Huiheng Qu,Ting Shan,Yigang Chen,Ye Chen,Jiazeng Xia 한국분자세포생물학회 2018 Molecules and cells Vol.41 No.7

The RNA-binding protein tristetraprolin (TTP) binds to adenosine- uridine AU-rich elements in the 3’-untranslated region of messenger RNAs and facilitates rapid degradation of the target mRNAs. Therefore, it regulates the expression of multiple cancer and immunity-associated transcripts. Furthermore, a lack of TTP in cancer cells influences cancer progression and predicts poor survival. Although the functions of TTP on cancer cells have previously been researched, the mechanism of TTP on the interaction between cancer cells with their microenvironment remains undiscovered. In this study, we admed to determine the role of cancer cell TTP during the interaction between tumor and immune cells, specifically regulatory T cells (Tregs). We evaluate the capability of TTP to modulate the antitumor immunity of GC and explored the underlying mechanism. The overexpression of TTP in GC cells dramatically increased peripheral blood mononuclear lymphocyte (PBML) -mediated cytotoxicity against GC cells. Increased cytotoxicity against TTP-overexpressed GC cells by PBMLs was determined by Treg development and infiltration. Surprisingly, we found the stabilization of programmed death-ligand 1 (PD-L1) mRNA was declining while TTP was elevated. The PDL1 protein level was reduced in TTP-abundant GC cells. PD-L1 gas been found to play a pivotal role in Treg development and functional maintenance in immune system. Taken together, our results suggest the overexpression of TTP in GC cells not only affects cell survival and apoptosis but also increases PBMLs -mediated cytotoxicity against GC cells to decelerate tumor progression. Moreover, we identified PD-L1 as a critical TTP-regulated factor that contributes to inhibiting antitumor immunity.

Microbial Subversion of Heparan Sulfate Proteoglycans

Ye Chen,Martin Götte,Jian Liu,Pyong Woo Park 한국분자세포생물학회 2008 Molecules and cells Vol.26 No.5

The interactions between the host and microbial pathogen largely dictate the onset, progression, and outcome of infectious diseases. Pathogens subvert host components to promote their pathogenesis and, among these, cell surface heparan sulfate proteoglycans are exploited by many pathogens for their initial attachment and subsequent cellular entry. The ability to interact with heparan sulfate proteoglycans is widespread among viruses, bacteria, and parasites. Certain pathogens also use heparan sulfate proteoglycans to evade host defense mechanisms. These findings suggest that heparan sulfate proteoglycans are critical in microbial pathogenesis, and that heparan sulfate proteoglycan-pathogen interactions are potential targets for novel prophylactic and therapeutic approaches.

Surfactant Effect on Formation of CaWO₄:Eu³⁺ Crystals with Distinguished Morphologies in Hydrothermal Ambient

Chen, Ye-Qing,Yang, Guo-Tao,Luo, Jian-Yi,Yang, Ying-Shu,Zeng, Qing-Guang,Jeong, Jung Hyun American Scientific Publishers 2016 Journal of nanoscience and nanotechnology Vol.16 No.4

<P>Metal tungstates, expressed by the general formula of MWO4, have important properties and applications in photoluminescence, microwave applications, optical fibers, scintillator materials, humidity sensors, magnetic properties, and catalysts. In this paper, we report a successful synthesis of CaWO4: Eu3+ crystals with various morphologies in mild hydrothermal conditions with surfacntant including sodium citrate, CTAB, PEG and citrate acid (CA). The formation of the crystals are strongly dependent on the employment of surfactant. The surfactant concentration has been found significant influence in the resulting morphologies due to different properties of each one. Extensive characterization have been performed by using X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM) in search of the formation mechanism of multi-morphological CaWO4: Eu3+ crystals. The growth mechanism of monodispersed CaWO4: Eu3+ crystal are proposed. And the photoluminescence properties were investigated.</P>

Progressive collapse of steel-framed gravity buildings under parametric fires

Jian Jiang,Wenyu Cai,Guo-Qiang Li,Wei Chen,Jihong Ye 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.36 No.4

This paper investigates the progressive collapse behavior of 3D steel-framed gravity buildings under fires with a cooling phase. The effect of fire protections and bracing systems on whether, how, and when a gravity building collapses is studied. It is found that whether a building collapses or not depends on the duration of the heating phase, and it may withstand a “short-hot” fire, but collapses under a mild fire or a “long-cool” fire. The collapse time can be conservatively determined by the time when the temperature of steel columns reaches a critical temperature of 550 °C. It is also found that the application of a higher level of fire protection may prevent the collapse of a building, but may also lead to its collapse in the cooling phase due to the delayed temperature increment in the heated members. The tensile membrane action in a heated slab can be resisted by a tensile ring around its perimeter or by tensile yielding lines extended to the edge of the frame. It is recommended for practical design that hat bracing systems should be arranged on the whole top floor, and a combination of perimeter and internal vertical bracing systems be used to mitigate the fire-induced collapse of gravity buildings. It is also suggested that beam-to-column connections should be designed to resist high tensile forces (up to yielding force) during the cooling phase of a fire.

Single-Handed Helical Poly-(α,β- unsaturated ketone) Synthesized via Anionic Polymerization of (S)-2'-Methyloxy- 2-Acrylyl-1,1'-Binaphthyl

Ye-Hui Chen,Li-Wen Yang,Nian-Fa Yang,Jian Zhang 한국고분자학회 2014 Macromolecular Research Vol.22 No.3

Review on Quantitative Measures of Robustness for Building Structures Against Disproportionate Collapse

Jiang, Jian,Zhang, Qijie,Li, Liulian,Chen, Wei,Ye, Jihong,Li, Guo-Qiang Council on Tall Building and Urban Habitat Korea 2020 International journal of high-rise buildings Vol.9 No.2

Disproportionate collapse triggered by local structural failure may cause huge casualties and economic losses, being one of the most critical civil engineering incidents. It is generally recognized that ensuring robustness of a structure, defined as its insensitivity to local failure, is the most acceptable and effective method to arrest disproportionate collapse. To date, the concept of robustness in its definition and quantification is still an issue of controversy. This paper presents a detailed review on about 50 quantitative measures of robustness for building structures, being classified into structural attribute-based and structural performance-based measures (deterministic and probabilistic). The definition of robustness is first described and distinguished from that of collapse resistance, vulnerability and redundancy. The review shows that deterministic measures predominate in quantifying structural robustness by comparing the structural responses of an intact and damaged structure. The attribute-based measures based on structural topology and stiffness are only applicable to elastic state of simple structural forms while the probabilistic measures receive growing interest by accounting for uncertainties in abnormal events, local failure, structural system and failure-induced consequences, which can be used for decision-making tools. There is still a lack of generalized quantifications of robustness, which should be derived based on the definition and design objectives and on the response of a structure to local damage as well as the associated consequences of collapse. Critical issues and recommendations for future design and research on quantification of robustness are provided from the views of column removal scenarios, types of structures, regularity of structural layouts, collapse modes, numerical methods, multiple hazards, degrees of robustness, partial damage of components, acceptable design criteria.

Tristetraprolin Overexpression in Gastric Cancer Cells Suppresses PD-L1 Expression and Inhibits Tumor Progression by Enhancing Antitumor Immunity

Guo, Jian,Qu, Huiheng,Shan, Ting,Chen, Yigang,Chen, Ye,Xia, Jiazeng Korean Society for Molecular and Cellular Biology 2018 Molecules and cells Vol.41 No.7

The RNA-binding protein tristetraprolin (TTP) binds to adenosine-uridine AU-rich elements in the 3'-untranslated region of messenger RNAs and facilitates rapid degradation of the target mRNAs. Therefore, it regulates the expression of multiple cancer and immunity-associated transcripts. Furthermore, a lack of TTP in cancer cells influences cancer progression and predicts poor survival. Although the functions of TTP on cancer cells have previously been researched, the mechanism of TTP on the interaction between cancer cells with their micro-environment remains undiscovered. In this study, we admed to determine the role of cancer cell TTP during the interaction between tumor and immune cells, specifically regulatory T cells (Tregs). We evaluate the capability of TTP to modulate the antitumor immunity of GC and explored the underlying mechanism. The overexpression of TTP in GC cells dramatically increased peripheral blood mononuclear lymphocyte (PBML) -mediated cytotoxicity against GC cells. Increased cytotoxicity against TTP-overexpressed GC cells by PBMLs was determined by Treg development and infiltration. Surprisingly, we found the stabilization of programmed death-ligand 1 (PD-L1) mRNA was declining while TTP was elevated. The PD-L1 protein level was reduced in TTP-abundant GC cells. PD-L1 gas been found to play a pivotal role in Treg development and functional maintenance in immune system. Taken together, our results suggest the overexpression of TTP in GC cells not only affects cell survival and apoptosis but also increases PBMLs -mediated cytotoxicity against GC cells to decelerate tumor progression. Moreover, we identified PD-L1 as a critical TTP-regulated factor that contributes to inhibiting antitumor immunity.

Characterization and utilization of a cytoplasmic male sterility line of Wucai (Brassica campestris L.)

Guohu Chen,Xinyu Ye,Fanli Zeng,Jian Wang,Lingyun Yuan,Shidong Zhu,Jinfeng Hou,Yuan Cheng,Chenggang Wang 한국원예학회 2019 Horticulture, Environment, and Biotechnology Vol.60 No.3

The novel male sterility line 12-14A of Wucai ( Brassica campestris ) was generated by backcrossing. In this study, morphological,molecular, and cytological analyses were performed to characterize this line. The phenotypes of fl ower organsof 12-14A were diff erent from those of its maintainer line 12-14B, as the fl owers of 12-14A were completely infertile. Molecular analysis confi rmed that the male sterility line 12-14A was classifi ed as the ogu CMS type. An analysis of antherdevelopment in the CMS line demonstrated that two types of abortion occur simultaneously: pollen mother cell abortionand tetrad-to-mononuclear microspore abortion. In addition, the mature anthers of 12-14A showed typical abortive features,such as appearing dry, shrunken, and scaly. A heterosis test of hybrids from CMS 12-14A and four inbred lines was carriedout, and the F 1 hybrids exhibited clear heterosis in plant weight, as well as in the protein, soluble sugar, and vitamin C content,suggesting high yields and high quality potential. These results indicate that this novel CMS line may have powerfulpotential in Wucai hybrid breeding.

Synthesis, properties, calculations and applications of small molecular host materials containing oxadiazole units with different nitrogen and oxygen atom orientations for solution-processable blue phosphorescent OLEDs

Hua Ye,Hongyu Wu,Liangyuan Chen,Songhua Ma,Kaifeng Zhou,Guobing Yan,Jiazhong Shen,Dongcheng Chen,Shi‑Jian Su 대한금속·재료학회 2018 ELECTRONIC MATERIALS LETTERS Vol.14 No.2

A series of new small molecules based on symmetric electron-acceptor of 1,3,4-oxadiazole moiety or its asymmetric isomerof 1,2,4-oxadiazole unit were successfully synthesized and applied to solution-processable blue phosphorescent organic lightemittingdiodes for the first time, and their thermal, photophysical, electrochemical properties and density functional theorycalculations were studied thoroughly. Due to the high triplet energy levels (ET, 2.82–2.85 eV), the energy from phosphorescentemitter of iridium(III) bis[(4,6-difluorophenyl)-pyridinate-N,C2′]picolinate (FIrpic) transfer to the host molecules couldbe effectively suppressed and thus assuring the emission of devices was all from FIrpic. In comparison with the para-modeconjugation in substitution of five-membered 1,3,4-oxadiazole in 134OXD, the meta-linkages of 1,2,4-isomer appending withtwo phenyl rings cause the worse conjugation degree and the electron delocalization as well as the lower electron-withdrawingability for the other 1,2,4-oxadiazole-based materials. Noting that the solution-processed device based on 134OXD containing1,3,4-oxadiazole units without extra vacuum thermal-deposited hole/exciton-blocking layer and electron-transportinglayer showed the highest maximum current efficiency (CEmax) of 8.75 cd/A due to the excellent charge transporting ability of134OXD, which far surpassed the similar devices based on other host materials containing 1,2,4-oxadiazole units. Moreover,the device based on 134OXD presented small efficiency roll-off with current efficiency (CE) of 6.26 cd/A at high brightnessup to 100 cd/m2. This work demonstrates different nitrogen and oxygen atom orientations of the oxadiazole-based hostmaterials produce major impact on the optoelectronic characteristics of the solution-processable devices.