Electroless plating of Co―Zn―P thin film onto nanodiamond cores

Zhi Xiang Zheng,Rui Wang,Chun Ming Wang 한국물리학회 2011 Current Applied Physics Vol.11 No.2

The purpose of this article is to introduce the Co―Zn―P film coated on the nanodiamond cores by electroless deposition. The surface morphology, composition and magnetic performance of the coatings are studied with the help of transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), an energy dispersive X-ray detector (EDX) and the vibrating sample magnetometer (VSM). The results showed that the change of film composition and magnetic characteristics were dependant on the content of Cobalt, Zinc and Phosphorus. Evidently the coercive force was affected by the atomic composition of alloy film While the best proportion (the optimal composition mass ratio of Cobalt and Zinc was 1:4) in alloy film, the alloy film has good electromagnetic properties, even though the Phosphorus wt.%≥3%.

The Phytotoxic Effects of Selenium–Mercury Interactions on Root Growth in Brassica rapa (LvLing)

Zhi-Wei Bian,Jian Chen,Hui Li,Dan-Dan Liu,Li-Fei Yang,Yue-Lin Zhu,Wen-Li Zhu,Wei Liu,Zheng-Zheng Ying 한국원예학회 2016 Horticulture, Environment, and Biotechnology Vol.57 No.3

Rapid industrial and agricultural development has dramatically increased the emission of selenium (Se) and mercury (Hg) into the environment. Combined soil pollution by Se and Hg poses a potential threat to crop production. However, no toxic effects of Hg–Se interactions on plants have been reported previously. In this study, we investigated the effects of Hg–Se interactions on biochemical and physiological indices in the roots of Brassica rapa (LvLing). Seedlings were treated hydroponically with solutions of mercury chloride (1 μM), sodium selenite (4 μM), or a combination of the two. Combined Hg+Se treatment significantly inhibited root growth, reduced root biomass, and enhanced reactive oxygen species (ROS) and malondialdehyde accumulation and led to a loss of plasma membrane integrity. The combined treatment increased glutathione peroxidase, glutathione S-transferase, and peroxidase activity, reduced superoxide dismutase activity, and had no effect on catalase activity. In addition, we detected increased glutathione concentrations in root tips and reduced ascorbic acid concentrations in the presence of Hg+Se relative to individual treatments with these elements. Thus, Hg–Se interactions enhanced oxidative injury, cell death, and phytotoxicity in B. rapa roots.

In vitro permeability, pharmacokinetics and brain uptake of WAY-100635 and FCWAY in rats using liquid chromatography electrospray ionization tandem mass spectrometry

Zhi Zheng,안소희,이병회,서혜원,배명애,안성훈 대한약학회 2015 Archives of Pharmacal Research Vol.38 No.6

Positron emission tomography (PET) is a sensitivenon-invasive imaging technique. To reduce imagingmeasurements of defects, there is a demand for proper LC–ESI–MS/MS method to carry out with its specificity andsensitivity. This study describes a rapid and simple liquidchromatography electrospray ionization tandem-MS/MS(LC–ESI–MS/MS) method for determination of both PETtracers: N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridyl)cyclohexanecarboxamide (WAY-100635)and 4-fluoro-N-[2-[4-(2-methoxylphenyl)-1-piperazino]ethyl]-N-(2-pyridyl)cyclohexanecarboxamide (FCWAY). Bothtarget compounds were prepared by one-step protein precipitationwith acetonitrile and methanol (1:1, v/v), andanalyzed using a C18 column. This simple method has anexcellent linearity, selectivity and sensitivity. Precision andaccuracy values for the intra-day and inter-day validationwere below 12 %. The limit of quantification (LOQ) forboth target compounds was defined as 1 ng/mL in plasmaand 5 ng/mL in brain homogenate. The stability of bothcompounds is considered stable under a various experimentalconditions. The in vitro MDR-MDCK cell permeabilityshowed the both compounds have high permeability(Papp, A?B C 20 9 10-6 cm/s) and low efflux ratio (B2.0). Brain to blood (AUCbrain/AUCblood) distribution ratios inrats were 3.15 ± 0.42 for WAY-100635 and 2.20 ± 0.34for FCWAY, respectively, and these results suggest thatLC–ESI–MS/MS method might be a supplementary wayfor the identifying and understanding of radiopharmaceuticals.

Determination of 2-(3-benzoyl)-4-hydroxy-1,1-dioxo-2H-1,2-benzothiazine-2-yl-1-phenylethanone by liquid chromatography-tandem mass spectrometry.

Zheng, Zhi,Song, Jin Sook,Lee, Byung Hoi,Ahn, Sung-Hoon,Ahn, Jin-Hee,Woo, JaeChun,Park, Ji-Young,Yoo, Dae Seok,Bae, Myung Ae 3M Company 2014 Journal of Chromatographic Science Vol.52 No.5

<P>2-(3-Benzoyl)-4-hydroxy-1,1-dioxo-2H-1,2-benzothiazine-2-yl-1-phenylethanone (KR-66344), a 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) inhibitor, is newly developed for the control of type 2 diabetes mellitus (T2DM) and metabolic syndrome. A method for the determination of KR-66344 in rat plasma was developed by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS-MS) to evaluate the pharmacokinetics of KR-66344. Plasma samples were processed by a liquid-liquid extraction method with ethyl acetate and introduced onto the LC-MS-MS system. The analyte and imipramine (internal standard) were analyzed by multiple reaction monitoring based on transitions at m/z 420.1 105.0 and 282.2 86.0, respectively. The calibration curve was linear (r = 0.9993) over the concentration range of 1.0-1,000 ng/mL. The mean recovery values for KR-66344 and imipramine were 83.8 and 86.2%, respectively. The mean inter-day and intra-day assay precision values were 3.9 and 2.4%, respectively. KR-66344 was stable under various handling and storage conditions. This developed method was applied to a pharmacokinetic study after the oral administration of KR-66344 in rats. The concentration of KR-66344 was readily measurable in rat plasma up to 24 h post-dose after an oral administration, suggesting that current assay is applicable to pharmacokinetic studies for KR-66344.</P>

Improvement of hEGF Production with Enhanced Cell Division Ability Using Dissolved Oxygen Responses to Pulse Addition of Tryptone

Zhi-Yong Zheng,Xiaobei Zhan,Chi Chung Lin,Shan-Jing Yao 한국생물공학회 2009 Biotechnology and Bioprocess Engineering Vol.14 No.1

Tryptone has multiple and complex effects on cell physiology and process performance in pulse fed-batch cultivation of recombinant Escherichia coli. By applying feedback control of dissolved oxygen signal responding to pulse in the feed rate, the production of acetate was avoided and the optimization of production of recombinant human epidermal growth factor (hEGF) was successfully achieved. With the addition of an optimum amount of tryptone along with glucose in the pulse fed-batch cultivation of E. coli, the ability of the cell to divide and the stability of the plasmid within the bacteria were improved. Consequently, segregation of the cells into a viable but non-culturable physiological state was alleviated. Addition of tryptone also enhanced cell respiration before and after hEGF expression and thus further benefited the production of recombinant hEGF. Excessive addition of tryptone resulted in low sensitivity of the oscillation of dissolved oxygen signal and poor operability of pulse fed-batch cultivation as this led to an accumulation of acetate, which weakened the dissolved oxygen signal responses. Consequently, the production of recombinant protein was considerably reduced. By combining the process performance and the positive effect of complex media pulse addition on bacterial metabolism, the optimal production conditions of hEGF were successfully determined. A high cell density of 91 g/L dry cell weight was obtained under these optimal production conditions. Furthermore, a high level of 0.24 g/L hEGF was attained leading to a 32.6% increase in product yield as compared to the controls.

The Risk of Gastrointestinal Cancer on Daily Intake of Low-Dose BaP in C57BL/6 for 60 Days

Zheng Zhi,Park Jung Kuk,Kwon Oh Wook,Ahn Sung Hoon,Kwon Young Joo,Jiang Linjuan,Zhu Shaohui,Park Byoung Hee 대한의학회 2022 Journal of Korean medical science Vol.37 No.30

Background: Benzo(a)pyrene (BaP) is a carcinogenic compound in contaminated foodstuffs. The effect of oral intake of the environmental carcinogen BaP under low doses and frequent exposure on a digestive system has not been thoroughly verified. Methods: In this regard, this study was conducted to prove the toxicity effects of BaP on the stomach and colon tissue after exposure to C57BL/6 mouse (3 and 6 µg/kg) following daily oral administration for 60 days. This study investigated acute gastric mucosal injury, severe gastric edema, cell infiltration, and mononuclear cells, multifocal cells, and tumoral inflammatory cells. Results: The results of ELISA showed that the expression of serum interleukin (IL)-6 and tumor necrosis factor-α in the BaP exposure group were significantly increased, and a high level of DNA adduct distribution in their stomach and colon. Moreover, this study has confirmed the expression of early carcinogenesis markers: nuclear factor (NF)-κB, p53, IL-6, superoxide dismutase 1 (SOD1), mucin (MUC1 and MUC2), and β-catenin in the stomach and colon, and showed that there was a significant increase in IL-6, NF-κB, SOD1, β-catenin, and MUC1 (P < 0.05). At the same time, there was a significant decrease in MUC2 and p53 (P < 0.05). Thus, even in low doses, oral intake of BaP can induce DNA damage, increasing the potential risk of gastrointestinal cancer. Conclusion: This study will provide a scientific basis for researching environmental contaminated food and intestinal health following daily oral administration of BaP.

The optimum steel fiber reinforcement for prestressed concrete containment under internal pressure

Zhi Zheng,Ye Sun,Xiaolan Pan,Chunyang Su,Jingchang Kong 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.6

This paper investigates the optimum fiber reinforcement for prestressed concrete containment vessels(PCCVs) under internal pressure. To achieve this aim, steel fiber, which is the most widely used fiber typein current engineering applications, is adopted to constitute steel fiber-reinforced concrete (SFRC) tosubstitute the conventional concrete in the PCCV. The effects of characteristic parameters, lsf , of the steelfiber affecting significantly the mechanical behavior of the concrete are first taken into account. Partial orcomplete concrete regions of the PCCV are also considered to be replaced by SFRC to balance theeconomy and safety. By adopting the ABAQUS software, the ultimate bearing capacity and performancefor the fiber-reinforced PCCV are scientifically studied and quantified, and the recommendations for theoptimum way of fiber reinforcement are presented.

Effect of Metabolic Structures and Energy Requirements on Curdlan Production by Alcaligenes faecalis

Zheng, Zhi-Yong,Lee, Jin-Woo,Zhan, Xiao Bei,Shi, Zhongping,Wang, Lei,Zhu, Li,Wu, Jian-Rong,Lin, Chi Chung Korean Society for Biotechnology and Bioengineerin 2007 Biotechnology and Bioprocess Engineering Vol.12 No.4

A comprehensive metabolic network was proposed for Alcaligenes faecalis and employed in a stoichiometrically based flux balance model for curdlan production optimization. The maximal yield of curdlan was evaluated for curdlan batch production. Various metabolic structures and metabolic pathway distributions related with the curdlan maximal yield was evaluated. The results showed that the energy efficiency rather than the substrate supply was the major constraint for the enhancement of curdlan production. The increase in specific rate of glucose uptake could enhance curdlan production yield due to the decrease of the ratio of metabolic maintenance to substrate consumption. However, some of the energy loss and nutrient limitation associated with the increase of metabolic maintenance would adversely affect the conversion efficiency of the substrate.

Baicalin Induces Apoptosis in Leukemia HL-60/ADR Cells via Possible Down-regulation of the PI3K/Akt Signaling Pathway

Zheng, Jing,Hu, Jian-Da,Chen, Ying-Yu,Chen, Bu-Yuan,Huang, Yi,Zheng, Zhi Hong,Liu, Ting-Bo Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.4

Background: The effect and possible mechanism of traditional Chinese medicine, baicalin, on the PI3K/Akt signaling pathway in drug-resistant human myeloid leukemia HL-60/ADR cells have been investigated in this current study. Methods: HL-60/ADR cells were treated by 20, 40, $80\;{\mu}mol/L$ baicalin followed by cell cycle analysis at 24h. The mRNA expression level of the apoptosis related gene, Bcl-2 and bad, were measured by RT-PCR on cells treated with $80\;{\mu}mol/L$ baicalin at 12, 24 and 48hr. Western blot was performed to detect the changes in the expression of the proteins related to HL-60/ADR cell apoptosis and the signaling pathway before and after baicalin treatment, including Bcl-2, PARP, Bad, Caspase 3, Akt, p-Akt, NF-${\kappa}B$, p-NF-${\kappa}B$, mTOR and p-mTOR. Results: Sub-G1 peak of HL-60/ADR cells appeared 24 h after $20\;{\mu}mol/L$ baicalin treatment, and the ratio increased as baicalin concentration increased. Cell cycle analysis showed 44.9% G0/G1 phase cells 24 h after baicalin treatment compared to 39.6% in the control group. Cells treated with $80\;{\mu}mol/L$ baicalin displayed a trend in decreasing of Bcl-2 mRNA expression over time. Expression level of the Bcl-2 and PARP proteins decreased significantly while that of the PARP, Caspase-3, and Bad proteins gradually increased. No significant difference in Akt expression was observed between treated and the control groups. However, the expression levels of p-Akt, NF-${\kappa}B$, p-NF-${\kappa}B$, mTOR and p-mTOR decreased significantly in a time-dependent manner. Conclusions: We conclude that baicalin may induce HL-60/ADR cell apoptosis through the PI3K/AKT signaling pathway.

Angelica sinensis Supercritical Fluid CO2 Extract Attenuates D-Galactose-Induced Liver and Kidney Impairment in Mice by Suppressing Oxidative Stress and Inflammation

Zhi-Zhun Mo,Zhi-Xiu Lin,ZiRen Su,Lin Zheng,Hui-Lin Li,JianHui Xie,Yan-Fang Xian,Tie-Gang Yi,Shui-Qing Huang,Jian-Ping Chen 한국식품영양과학회 2018 Journal of medicinal food Vol.21 No.9

Angelica sinensis (AS, Danggui in Chinese) is an important herbal component of various traditional formulae for the management of asthenia and its tonic effects. Although AS has been shown to ameliorate cognitive damage and nerve toxicity in D-galactose (D-gal)-elicited senescent mice brain, its effects on liver and kidney injury have not yet been explored. In this work, mice were subjected to hypodermic injection with D-gal (200 mg/kg) and orally gavaged with AS (20, 40, or 80 mg/kg) once a day for 8 successive weeks. Results revealed that AS significantly improved liver and kidney function as assessed by organ index and functional parameters. In addition, AS pretreatment effectively ameliorated the histological deterioration. AS attenuated the MDA level and markedly enhanced the activities and gene expressions of antioxidative enzymes, namely Cu, Zn-SOD, CAT, and GPx. Furthermore, AS markedly inhibited the D-gal-mediated increment of expressions of inflammatory cytokines iNOS, COX-2, IκBα, p-IκBα, and p65 and promoted the IκBα expression level in both hepatic and renal tissues. In sum, AS pretreatment could effectively guard the liver and kidney of mice from D-gal-induced injury, and the underlying mechanism was deemed to be intimately related to attenuating oxidative response and inflammatory stress.