Intracellular Localization and Sustained Prodrug Cell Killing Activity of TAT-HSVTK Fusion Protein in Hepatocelullar Carcinoma Cells

Limin Cao,Jin Si,Weiyu Wang,Xiaorong Zhao,Xiaomei Yuan,Huifen Zhu,Xiaolong Wu,Jianzhong Zhu,Guanxin Shen 한국분자세포생물학회 2006 Molecules and cells Vol.21 No.1

Gene therapy with nonviral vectors using the suicide gene/prodrug activating system of herpes simplex virus type-1 thymidine kinase (HSV1-TK)/ganciclovir (GCV) is inefficient in killing malignant tumor cells due to two major factors: (a) an unsatisfactory bystander effect; (b) short-lived expression of the protein. To study the capacity of the protein transduction domain (PTD) of HIV-1 TAT protein to enhance HSV1-TK/GCV cancer gene therapy, we constructed three fusion proteins TAT-TK, TK-TAT and TK. TATTK retained as much enzyme activity as TK, whereas that of TK-TAT was much lower. TAT-TK can enter HepG2 cells and much of it is translocated to the nucleus. The transduced HepG2 cells are killed by exogenously added GCV and have bystander effects on untransduced HepG2 cells. Most importantly, the introduced recombinant protein is stable and remains functional for several days at least, probably because nuclear localization protects it from the cytoplasmic degradation machinery and provides access to the nuclear transcription machinery. Our results indicate that TAT fusion proteins traffic intercellularly and have enhanced stability and prodrug cell killing activity. We conclude that TAT has potential for enhancing enzyme prodrug treatment of liver cancers.

Three-dimensional modelling of water flow due to leakage from pressurized buried pipe

Zhu, Hong,Zhang, Limin,Chen, Chen,Chan, Kit Techno-Press 2018 Geomechanics & engineering Vol.16 No.4

A three-dimensional model is constructed to simulate water infiltration in an unsaturated slope from a leaking pipe. Adaptive mesh refinement and time stepping are used, assisted by an automatic procedure for progressive steepening of the hydraulic property function for better convergence. The model is justified by comparing the simulated results with experimental data. Steady-state flow is investigated considering various pipe water pressures, locations and sizes of the opening, and soil layering. The opening size significantly affects the soaked zone around the pipe. Preferential flow dominates along the pipe longitudinal direction in the presence of a loose backfill around the pipe.

Bioactive Compounds / Food Microbiology : Purification and Characterization of a New κ-Carrageenase from the Marine Bacterium Vibrio sp. NJ-2

( Ben Wei Zhu ),( Limin Ning ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.2

The carrageenan-degrading marine bacterium Vibrio sp. strain NJ-2 was isolated from rotten red algae, and κ-carrageenase with high activity was purified from the culture supernatant. The purified enzyme with molecular mass of 33 kDa showed the maximal activity of 937 U/mg at 40°C and pH 8.0. It maintained 80% of total activity below 40°C and between pH 6.0 and 10.0. The kinetics experiment showed the K_{m} and V_{max} values were 2.54 mg/ml and 138.89 mmol/min/mg, respectively. The thin layer chromatography and ESI-MS analysis of hydrolysates indicated that the enzyme can endolytically depolymerize the κ-carrageenan into oligosaccharides with degrees of depolymerization of 2-8. Owing to its high activity, it could be a valuable tool to produce κ-carrageenan oligosaccharides with various biological activities.

Preparation and Electrochemical Performances of Rod-Like LiV3O8/Carbon Composites Using Polyaniline as Carbon Source

Xiao-Yu Cao,Limin Zhu,Hailian Wu 대한금속·재료학회 2015 ELECTRONIC MATERIALS LETTERS Vol.11 No.4

Rod-like LiV3O8/carbon composites were successfully prepared by the polymer graphitization of LiV3O8/polyaniline composites, which were synthesized through the in-situ oxidative polymerization method. The crystal phases of as-prepared samples, confirmed by X-ray diffraction, show that the interlayer spacing in LiV3O8/ carbon composites is much wider than that of the pristine LiV3O8. Compared to the bare LiV3O8, the longer and smoother rod-like LiV3O8/carbon composites, investigated by scanning electron microscope and transmission electron microscope, were covered by a continuously thin layer of fluffy carbon with a thickness of approximate 20 nm. The optimal LiV3O8/carbon composite delivered a discharge capacity of 219.37 mAh g−1 in the initial cycle, and maintained a high capacity of 263.538 mAh g−1 at the 30th cycle, which was much higher than that of the pristine LiV3O8 (227.645 mAh g−1). Cyclic voltammetry measurements disclose that, after the carbon coating treatment, the phase transition of the optimal LiV3O8/carbon composite proceeds more reversibly and smoothly during charging/discharging. The improved cyclability of the optimal LiV3O8/carbon composite should be attributed to the confinement from thin carbon layer, the structural stability, the good interfacial compatibility, and the well-preserved electrode morphology after prolonged cycles.

Characterization of Volatile Compounds in Donkey Meat by Gas Chromatography–Ion Mobility Spectrometry (GC–IMS) Combined with Chemometrics

Mengmeng Li,Mengqi Sun,Wei Ren,Limin Man,Wenqiong Chai,Guiqin Liu,Mingxia Zhu,Changfa Wang 한국축산식품학회 2024 한국축산식품학회지 Vol.44 No.1

Volatile compounds (VOCs) are an important factor affecting meat quality. However, the characteristic VOCs in different parts of donkey meat remain unknown. Accordingly, this study represents a preliminary investigation of VOCs to differentiate between different cuts of donkey meat by using headspace–gas chromatography–ion mobility spectrometry (HS–GC–IMS) combined with chemometrics analysis. The results showed that the 31 VOCs identified in donkey meat, ketones, alcohols, aldehydes, and esters were the predominant categories. A total of 10 VOCs with relative odor activity values ≥1 were found to be characteristic of donkey meat, including pentanone, hexanal, nonanal, octanal, and 3-methylbutanal. The VOC profiles in different parts of donkey meat were well differentiated using three- and two-dimensional fingerprint maps. Nine differential VOCs that represent potential markers to discriminate different parts of donkey meat were identified by chemometrics analysis. These include 2-butanone, 2- pentanone, and 2-heptanone. Thus, the VOC profiles in donkey meat and specific VOCs in different parts of donkey meat were revealed by HS–GC–IMS combined with chemometrics, whcih provided a basis and method of investigating the characteristic VOCs and quality control of donkey meat.

Ultra-Precision Diamond Turning Error Compensation via Iterative Learning from On-machine Measured Data

ZaoZao Chen,WeiWei Huang,ZhiWei Zhu,XinQuan Zhang,LiMin Zhu,XiangQian Jiang 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.24 No.12

In ultra-precision diamond turning, the reduction of machining form errors can generally be achieved through on-machine measurement and compensation. However, the efficiency of conventional compensation methods is often insufficient, particularly when high form accuracy is required or when intricate surface topography and microstructures need to be machined. Consequently, this research proposes a novel machining error compensation method based on iterative learning from on-machine measured data to enhance the machining accuracy and compensation efficiency. The on-machine measurement system and cutting path generation algorithm are introduced first. Then, the compensation method via iterative learning is presented theoretically, demonstrating a higher convergence order compared to the conventional method. Finally, machining experiments involving the cutting of cosine surfaces are conducted, followed by measurements of the processed workpieces. The experimental results indicate that after four rounds of compensation using the conventional method, the peak-to-valley (PV) value of the form error is reduced to 0.1134 μm. In contrast, employing the proposed method, a similar value of 0.1156 μmis achieved after only two rounds of compensation. This highlights the significant reduction in compensation time facilitated by the proposed method. Furthermore, the measurement results verify that the proposed compensation method maintains excellent surface quality.

Effect of ultrahigh pressure processing (UHP) on physicochemical properties, antioxidant activity and anti-inflammatory activity of insoluble dietary fiber from Pholiota nameko

Haiping Li,Xinqi Guo,Xun Zhu,Yina Chen,Limin Zhang,Jiaqi Lu,Qiuting Qian 한국식품과학회 2024 Food Science and Biotechnology Vol.33 No.2

The aim of this study was to evaluate the effect of ultrahigh pressure processing (UHP) of 200, 300, 400, 500, 600 and 700 MPa for 20, 40 and 30 min on physicochemical and bioactive properties of the insoluble dietary fiber Pholiota nameko (PN-IDF). The results revealed that UHP were capable of decreasing the particle size of PN-IDF and binding phenolic content. Moreover, UHP technique had an improving effect on the bioaccessible phenolic content, the water-holding capacity, the oil-holding capacity and the nitrite ion adsorption capacity. Further, UHP technique presented a promoting effect on the antioxidant activity by scavenging ABTS or DPPH free radicals and increasing reducing power, and the anti-inflammatory activity by inhibiting carrageenan-induced paw edema on PN-IDF. Overall, this study well proved that UHP technology could improve the physicochemical and functional quality of PN-IDF, which could be used as a promising green technique for functional food ingredients processing.

A design of transmission-type multi-target X-ray tube based on electric field modulation

Zhao, Lei,Jia, Wenbao,Jin, Limin,Shan, Qing,Cheng, Can,Zhu, Hongkui,Hei, Daqian Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.9

Multi-target X-ray tube is a new type X-ray source, and can be applied in many fields such as sensitive X-ray fluorescence analysis and medical imaging. In this work, we report an electric field modulation multi-target X-ray tube, which contains four targets (Cr, Ni, Au, Mo) coated on a Beryllium (Be) window. A four-valve electric field deflector was developed to deflect the electron beam to bombard the corresponding targets. Particle dynamics analysis software was employed to simulate the particle tracking of electron beam. The results show that the 30 keV electron beam could get a 6.7 mm displacement on the target plane by 10⁵ V/m electric field. The focus areas are about 2 mm × 5 mm and 4 mm × 2.5 mm after deflection in two directions. Thermal behavior calculated by ANSYS shows that the designed target assembly could withstand a 10 W continuous power. The optimum target thicknesses and emission spectra were obtained by Geant4 when the thickness of Be window was 300 mm and the electron beam incident angle was 0.141 rad. The results indicate that this multi-target X-ray tube could provide different X-ray sources effectively.

Effects of zinc sources and levels of zinc amino acid complex on growth performance, hematological and biochemical parameters in weanling pigs

Zhang, Yi,Ward, Terry Lynn,Ji, Fei,Peng, Chucai,Zhu, Lin,Gong, Limin,Dong, Bing Asian Australasian Association of Animal Productio 2018 Animal Bioscience Vol.31 No.8

Objective: The objective of the study was to investigate the effects of zinc amino acid complex (ZnAA) on growth performance, hematological and biochemical parameters in weanling pigs. Methods: In Exp. 1, a total of 216 Duroc${\times}$Landrace${\times}$Large White weanling pigs were assigned randomly to 6 dietary treatments. Each treatment had 6 replicates (pens) with 6 pigs each. The diets were corn-soybean meal based with supplementation of 0, 20, 40, 80, 120 mg Zn/kg from ZnAA or 40 mg Zn/kg from feed-grade zinc sulfate. The experiment lasted 42 days. In Exp. 2, a total of 180 weanling pigs were assigned randomly to 3 dietary treatments supplemented with 0, 80, or 800 mg Zn/kg from ZnAA. Results: In Exp. 1, pigs fed 40 to 80 mg Zn/kg from ZnAA had higher (p<0.05) average daily gain (ADG) than the unsupplemented group during d 0 to 14. During d 0 to 42, the pigs fed 20 to 120 mg Zn/kg from ZnAA had increased (p<0.05) ADG. Pigs fed 20 to 120 mg/kg Zn from ZnAA had lower feed:gain (p<0.05), increased the activity of serum Cu-Zn superoxide dismutase on d 14, and increased serum Zn levels on d 42 (p<0.05). In Exp. 2, pigs fed diets with 800 mg Zn/kg had increased average daily feed intake during d 15 to 28 (p<0.05) compared to the unsupplemented group. During d 0 to 28, the pigs fed supplemental Zn had increased ADG (p<0.05). On d 14 and d 28, pigs fed supplemental Zn had higher the serum alkaline phosphatase activities (p<0.05). No significant differences were observed in the hematological parameters and organ indices. Conclusion: Supplementation with 20 to 80 mg/kg Zn from ZnAA improved the growth performance in weaned pigs. The piglets can tolerate up to 800 mg/kg Zn from ZnAA with limited potential health effects.