Catalytic enantioselective synthesis of α-chiral azides

Ding, Pei-Gang,Hu, Xiao-Si,Zhou, Feng,Zhou, Jian The Royal Society of Chemistry 2018 ORGANIC CHEMISTRY FRONTIERS Vol.5 No.9

<P>α-Chiral azides represent a special subclass of chiral amines, which not only widely exist in bioactive compounds but also play a significant role as a building block in a variety of value-added chiral products. The catalytic asymmetric synthesis of α-chiral azides is of current interest and three synthetic strategies have been developed. This review summarizes the recent progress in this research area, discusses the advantages and limitations of each strategy, and outlines synthetic opportunities for future research.</P>

Flexural Decoupling Analysis Method of Composite Box Girder with Corrugated Steel Webs

Zhou Mao-Ding,Zhang Yuan-Hai,Ji Wei 한국강구조학회 2024 International Journal of Steel Structures Vol.24 No.1

The existing flexural analysis methods of corrugated steel web composite box girders are either inaccurate due to thoughtlessness of the influencing factors, or complicated due to excessive consideration of the influencing factors. In this study, a flexural displacement model of composite box girder considering both the accordion effect and shear deformation of web and the shear lag effect of flange is proposed. According to the internal force balance condition, the complex flexural models of a composite box girder are decoupled into three independent simple flexural states: Euler–Bernoulli beam flexure satisfying the quasi-plane assumption, flexure of equivalent web deformation, and flexure of shear lag of flange. Based on the flexural theory of the thin-walled beam, the generalized internal force system and beam-type finite element model was established corresponding to each flexural state. The results of numerical examples show that the proposed method has high solution accuracy and can directly obtain the displacement and internal force of each flexure deformation. The moment results show that the generalized moment has a peak value at the point of shear discontinuity, and increases or decays rapidly near it.

Fixed-time Output Feedback Consensus of Second-order Multi-agent Systems with Settling Time Estimation

Ding Zhou,An Zhang,Pan Yang 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.8

This study discusses fixed-time consensus problem of second-order multi-agent systems with unmeasurable velocity and uncertain disturbance. The proposed control scheme includes two parts: one part is a fixed-time convergent state observer to estimate the unknown velocity while the other part is a fixed-time consensus algorithm based on integral sliding mode. Mathematical proof is given and some stability conditions are derived. Moreover, the settling time depends on the parameters of state observer and consensus algorithm, which can be theoretically estimated offline regardless of initial states. Finally, the proposed control scheme is employed to coordinated control of single-link robotic manipulators and the simulation examples verify the efficiency of the results.

Effect of fermented blueberry on the oxidative stability and volatile molecule profiles of emulsion-type sausage during refrigerated storage

Zhou, Hengyue,Zhuang, Xinbo,Zhou, Changyu,Ding, Daming,Li, Chunbao,Bai, Yun,Zhou, Guanghong Asian Australasian Association of Animal Productio 2020 Animal Bioscience Vol.33 No.5

Objective: The aim of this work was to assess the effect of fermented blueberry (FB; 2%, 4%, and 6%) on the oxidative stability and volatile molecule profiles of emulsion-type sausage stored at 4℃ for 28 days. Methods: The antioxidant activity of FB was determined through radical-scavenging activity against 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radicals. Four formulations of sausage treatments with different FB levels (0%, 2%, 4%, 6%) were prepared, then peroxide value (POVs), thiobarbituric acid-reactive substances (TBARS) values, protein carbonyls and thiol groups were measured. The aroma profiles of sausages for each treatment was also determined. Results: The half maximal inhibitory concentration indicated that FB had greater scavenging ability than ascorbic acid against DPPH and hydroxyl radicals. Sausages with FB significantly retarded increases in POVs and TBARS, as well as in the content of protein carbonyls during all storage days (p<0.05). Particularly, 4% and 6% FB-treated sausages had better oxidation inhibition effects. However, FB accelerated the reduction in thiol groups (p<0.05). Additionally, FB inhibits the excessive formation of aldehyde compounds; for example, hexanal, which may cause rancid flavors, decreased from 58.25% to 19.41%. FB also created 6 alcohols (i.e., 2-methyl-1-propanol, 3-methyl-1-butanol, and phenylethyl alcohol), 5 ester compounds (i.e., ethyl acetate, ethyl lactate, and ethyl hexanoate) and 3-hydroxy-2-butanone in the sausages that contribute to sausage flavors. The principal component analysis showed that the aroma profiles of sausages with and without FB are easily identified. Conclusion: The addition of FB could significantly reduce the lipid and protein oxidation and improve oxidative stability for storage. Also, adding FB could inhibit rancid flavors and contribute to sausage flavors.

Original Article: Food Science/Microbiology : Antioxidant and Antimicrobial Activities of Camellia Oleifera Seed Oils

( Qing Fen Zhou ),( Xue Jing Jia ),( Qian Qian Li ),( Rui Wu Yang ),( Li Zhang ),( Yong Hong Zhou ),( Chun Bang Ding ) 한국응용생명화학회(구 한국농화학회) 2014 Journal of Applied Biological Chemistry (J. Appl. Vol.57 No.2

The antioxidant and antimicrobial activities of Camellia oleifera seed oil were studied. Four kinds of seed oil samples were prepared, crude oil and refined oil, extracted by cold pressing method (CPC, CPR), and organic solvent extraction (OSC, OSR). Antioxidant activity analysis was measured in 2,2-azinobis (3- ethylbenzothiazoline-6-sulfonic acid)-diammonium salt, ferric reducing Ability of Plasma, and 2,2-diphenyl-1-picrylhydrazyl assays. Besides, the percentage of inhibition of red blood cells hemolysis induced by 2,2´-azobis(2-amidnopropane) dihydrochlorid, the lag time of LDL conjugated dienes formation in vitro, and the inhibitors of loss in tryptophan fluorescence were all used to estimate the antioxidant activity of the samples. The total phenolic contents (TPC) were detemined by Folin-Ciocalteu method. The TPC of the C. oleifera seed oils can be arranged in descending order: CPC (1.9172 μg/mL) > OSC (1.5218 μg/mL) > CPR (1.0611 μg/mL) > OSR (0.6782 μg/mL). And the oils were investigated for activity against Escherichia coli, Bacillus subtilis, Saccharomyces cerevisiae and Aspergillus niger. The results showed the antioxidant activity of crude oil by cold pressing method was stronger than others, and all oils did inhibit activity of the top three bacteria expert A. niger. The further significance of the study contributes to measure the antioxidant and antimicrobial activity of the potential health benefits by the different methods of preparation and the oil of C. oleifera seeds acting as free radical scavenger, pharmaceuticals and preservatives may offer some information in medicine and cosmetic not just in food field.

Human Intersectin 2 (ITSN2) binds to Eps8 protein and enhances its degradation

( Xiao Feng Ding ),( Zijian Yang ),( Fang Liang Zhou ),( Xiang Huchang ),( Zhou Chang Luo ),( Zhi Cheng He ),( Qian Liu ),( Hong Li ),( Feng Yan ),( Fang Mei Wang ),( Shuang Lin Xiang ),( Jian Zhang ) 생화학분자생물학회 (구 한국생화학분자생물학회) 2012 BMB Reports Vol.45 No.3

Participates in actin remodeling through Rac and receptor endocytosis via Rab5. Here, we used yeast two-hybrid system with Eps8 as bait to screen a human brain cDNA library. ITSN2 was identified as the novel binding factor of Eps8. The interaction between ITSN2 and Eps8 was demonstrated by the in vivo co-immunoprecipitation and colocalization assays and the in vitro GST pull-down assays. Furthermore, we mapped the interaction domains to the region between amino acids 260-306 of Eps8 and the coiled-coil domain of ITSN2. In addition, protein stability assays and immunofluorescence analysis showed ITSN2 overexpression induced the degradation of Eps8 proteins, which was markedly alleviated with the lysosome inhibitor NH4Cl treatment. Taken together, our results suggested ITSN2 interacts with Eps8 and stimulates the degradation of Eps8 proteins. [BMB reports 2012; 45(3): 183-188]

Statistical characteristics of sustained wind environment for a long-span bridge based on long-term field measurement data

Ding, Youliang,Zhou, Guangdong,Li, Aiqun,Deng, Yang Techno-Press 2013 Wind and Structures, An International Journal (WAS Vol.17 No.1

The fluctuating wind induced vibration is one of the most important factors which has been taken into account in the design of long-span bridge due to the low stiffness and low natural frequency. Field measurement characteristics of sustained wind on structure site can provide accurate wind load parameters for wind field simulation and structural wind resistance design. As a suspension bridge with 1490 m main span, the Runyang Suspension Bridge (RSB) has high sensitivity to fluctuating wind. The simultaneous and continuously wind environment field measurement both in mid-span and on tower top is executed from 2005 up to now by the structural health monitoring system installed on this bridge. Based on the recorded data, the wind characteristic parameters, including mean wind speed, wind direction, the turbulence intensity, the gust factors, the turbulence integral length, power spectrum and spatial correlation, are analyzed in detail and the coherence functions of those parameters are evaluated using statistical method in this paper. The results indicate that, the turbulence component of sustain wind is larger than extremely strong winds although its mean wind speed is smaller; the correlation between turbulence parameters is obvious; the power spectrum is special and not accord with the Simiu spectrum and von Karman spectrum. Results obtained in this study can be used to evaluate the long term reliability of the Runyang Suspension Bridge and provide reference values for wind resistant design of other structures in this region.

Over-expression of phosphoenolpyruvate carboxylase cDNA from C4 millet (Seteria italica) increase rice photosynthesis and yield under upland condition but not in wetland fields

Ding, Zai-Song,Huang, Su-Hua,Zhou, Bao-Yuan,Sun, Xue-Fang,Zhao, Ming 한국식물생명공학회 2013 Plant biotechnology reports Vol.7 No.2

Phosphoenolpyruvate carboxylase (PEPC) catalyzes the initial fixation of $CO_2$ in $C_4$ plants. Under the control of the rice Rubisco small subunit promoter, cDNA of a $C_4$ SiPPC gene cloned from Seteria italica was introduced into Japonica rice by Agrobacterium-mediated transformation. Integration of the gene was confirmed by PCR analysis. RT-PCR showed expression of the gene at the RNA level in transgenic plants, and enzyme activity measurements confirmed the increase in PEPC protein. The transformants showed improvements in both photosynthesis rate and yield only under upland field cultivation. The possible function of PEPC in rice stress tolerance is discussed.

As a Modulator, Multitasking Roles of SIRT1 in Respiratory Diseases

Zhou Yunxin,Zhang Fan,Ding Junying 대한면역학회 2022 Immune Network Vol.22 No.3

As far the current severe coronavirus disease 2019 (COVID-19), respiratory disease is still the biggest threat to human health. In addition, infectious respiratory diseases are particularly prominent. In addition to killing and clearing the infection pathogen directly, regulating the immune responses against the pathogens is also an important therapeutic modality. Sirtuins belong to NAD+-dependent class III histone deacetylases. Among 7 types of sirtuins, silent information regulator type-1 (SIRT1) played a multitasking role in modulating a wide range of physiological processes, including oxidative stress, inflammation, cell apoptosis, autophagy, antibacterial and antiviral functions. It showed a critical effect in regulating immune responses by deacetylation modification, especially through high-mobility group box 1 (HMGB1), a core molecule regulating the immune system. SIRT1 was associated with many respiratory diseases, including COVID-19 infection, bacterial pneumonia, tuberculosis, and so on. Here, we reviewed the latest research progress regarding the effects of SIRT1 on immune system in respiratory diseases. First, the structure and catalytic characteristics of SIRT1 were introduced. Next, the roles of SIRT1, and the mechanisms underlying the immune regulatory effect through HMGB1, as well as the specific activators/inhibitors of SIRT1, were elaborated. Finally, the multitasking roles of SIRT1 in several respiratory diseases were discussed separately. Taken together, this review implied that SIRT1 could serve as a promising specific therapeutic target for the treatment of respiratory diseases.

Analytical solutions to piezoelectric bimorphs based on improved FSDT beam model

Zhou, Yan-Guo,Chen, Yun-Min,Ding, Hao-Jiang Techno-Press 2005 Smart Structures and Systems, An International Jou Vol.1 No.3

This paper presents an efficient and accurate coupled beam model for piezoelectric bimorphs based on improved first-order shear deformation theory (FSDT). The model combines the equivalent single layer approach for the mechanical displacements and a layerwise modeling for the electric potential. General electric field function is proposed to reasonably approximate the through-the-thickness distribution of the applied and induced electric potentials. Layerwise defined shear correction factor (k) accounting for nonlinear shear strain distribution is introduced into both the shear stress resultant and the electric displacement integration. Analytical solutions for free vibrations and forced response under electromechanical loads are obtained for the simply supported piezoelectric bimorphs with series or parallel arrangement, and the numerical results for various length-to-thickness ratios are compared with the exact two-dimensional piezoelasticity solution. Excellent predictions with low error estimates of local and global responses as well as the modal frequencies are observed.