Structural and nanomechanical properties of a-plane ZnO thin films deposited under different oxygen partial pressures

Sheng-Rui Jian,Hou-Guang Chen,Guo-Ju Chen,Jason S.C. Jang,Jenh-Yih Juang 한국물리학회 2012 Current Applied Physics Vol.12 No.3

The effects of O2 partial pressure during RF magnetron sputtering on the structural and nanomechanical properties of a-plane ZnO thin films were investigated by using X-ray diffraction (XRD) and nanoindentation techniques. The XRD and the transmission electron microscopy (TEM) selected area diffraction results indicate that the epitaxial relationship between ZnO thin films and Al2O3 substrates is ZnO ð1120Þ//Al2O3 ð1102Þ. The average values of the hardness and Young’s modulus of the a-plane ZnO films were found to decrease with increasing oxygen partial pressure. The cross-sectional TEM revealing the localized plastic deformation of ZnO thin films beneath the Berkovich indenter, indicating the prominent role played by the threading dislocations in the film deformation behavior. At higher indentation loadings, the sapphire substrate exhibits extensive deformation with narrow slip bands appearing on {0001} plane. However, no evidence of pressure-induced phase transformation, as well as cracking and/or delamination phenomena at the filmesubstrate interface was observed.

Detoxification, antioxidant, and digestive enzyme activities and gene expression analysis of Lymantria dispar larvae under carvacrol

Chen Yun-ze,Zhang Bo-wen,Yang Jing,Zou Chuan-shan,Li Tao,Zhang Guo-cai,Chen Guang-sheng 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.1

Carvacrol is a terpene compound with various biological activities. However, few studies have specifically focused on its insecticidal activity and mechanism of carvacrol. The larvae of Lymantria dispar are seriously harmful herbivorous insect. This study measured the antifeedant, growth-inhibitory, and toxic effects of carvacrol on L. dispar larvae. To further clarify the insecticidal mechanism of carvacrol, the effects of carvacrol on detoxifying enzymes, antioxidative enzymes, digestive enzyme activities, and the mRNA expression of the abovementioned enzyme genes were investigated. The results of the study showed that the median lethal concentration (LC 50 ) and the sublethal concentration (LC 20 ) of carvacrol were 1.120 mg/mL and 0.297 mg/mL, respectively, at 72 h. After LC 20 treatment of L. dispar larvae for 72 h, food intake and weight gain were significantly lower compared with the control. Enzyme activity assays showed that carvacrol significantly inhibited the activities of carboxylesterase (CarE), glutathione S-transferase (GST), and acetylcholinesterase (AchE), and the inhibition rate of AchE activity was highest (66.51%). Carvacrol also activated the activities of superoxide dismutase (SOD) and catalase (CAT), while it inhibited the activities of lipase (LIP) and amylase (AMS), and first inhibited and then activated protease. In addition, qRT-PCR tests showed that carvacrol affected the mRNA expression levels of CarE, GST, AchE, SOD, CAT, LIP, AMS, and protease. This study helps to clarify the insecticidal mechanism of carvacrol on L. dispar larvae.

Determination of Thermal Equilibrium in a Sealed Cell Based on Optical Depth

Sheng Zou,Hong Zhang,Xi-Yuan Chen,Guang-cun Shan,Wei Quan 한국물리학회 2017 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.70 No.2

An effective method based on optical depth (OD) is presented to measure thermal equilibrium in a cell. First, the principle of determining the temperature distribution in the cell by using the OD is demonstrated. Subsequently, relevant experiments are carried out. Original experimental results showed that some gradients of OD distributions in the cell at different wavelengths and variations of the OD increased slowly along the direction of motion of the beam at a fixed wavelength. At a wavelength of 766.6839 nm, which is about 7 GHz blue shifted with respect to the potassium resonance, the average value of the OD was about 0.764 and the maximal and the minimum inhomogeneity biases among all location points were about 6.07% and 0.56%, respectively. As for the corresponding wavelengths of 766.67785 nm and 766.73004 nm, some deviations from previous results, which were caused by different absorptions of the alkali-metal atoms at different frequencies of the laser beam, were observed. The nonuniform OD values along the direction of motion of the beam reflected an inhomogeneous distribution of the temperature in the cell, which may have been caused by layout of the oven. When the layout of the oven was modified, comparative experiments comparable to these with the previous layout of the oven demonstrated that the uniformity of the temperature distribution in the cell was improved and that thermal equilibrium time was shorter by about 10 minutes. This method played an important role in determining the thermal equilibrium time in the cell.

Detection of PCB77 by Indirect Competitive Enzyme-linked Immunosorbent Assay in Sea Sediment Samples

Chen, Han-Yu,Zhuang, Hui-Sheng,Yang, Guang-Xin Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.3

3,3',4,4'-Tetrachlorobiphenyl (IUPAC PCB77) is one of seven indicative polychlorinated biphenyls (PCBs) in the surface sediments. The current study presents a novel polyclonal antibody for the determination of the PCB77 using indirect competitive enzyme-linked immunosorbent assay. Under optimum conditions, PCB77 was determined within the concentration range of 0.01-100 ${\mu}g\;L^{-1}$, with a detection limit of 0.057 ${\mu}g\;L^{-1}$. The assays were tested for their cross-reactivity profiles using 3 selected congeners and 4 Aroclor products. The assays were highly specific for coplanar PCB congeners, but less specific for Aroclor1248. The spiked recoveries from five sediment samples were 86%-114% for PCB77 from ELISA, which were satisfactory. The current study demonstrated that the developed antiserum and immunoassay procedure can be used to detect PCB77 in environmental samples. The results of the sediment analysis were confirmed by conventional GC/ECD.

Expression and Prognostic Role of MEKK3 and pERK in Patients with Renal Clear Cell Carcinoma

Chen, Qi,Lu, Hong-sheng,Gan, Mei-fu,Chen, Lan-xi,He, Kai,Fan, Guang-min,Cao, Xue-quan Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.6

Mitogen-activated protein kinase/extracellular signal-regulated kinase kinase kinase 3 (MEKK3) is an important serine/threonine protein kinase and a member of the MAPK family. MEKK3 can effectively activate the MEK/ERK signaling pathway and promote an autocrine growth loop critical for tumor genesis, cell proliferation, terminal differentiation, apoptosis and survival. To explore the relationship between MEKK3 and cell apoptosis, clinicopathology and prognosis, we characterize the expression of MEKK3, pERK and FoxP3 in the renal clear cell carcinoma (RCCC). Protein expression was detected by tissue microarray and immunochemistry in 46 cases of RCCC and 28 control cases. Expression levels of CD3+,CD3+CD4+,CD3+CD8+,CD4+CD25+, CD4+CD25+ FoxP3+ were assessed by flow cytometry and analyzed for their association with pathological factors, correlation and prognosis in RCCC. Expression of MEKK3, pERK and FoxP3 was significantly up-regulated in RCCC as compared to control levels (p<0.01), associated with pathological grade (p<0.05)and clinical stage (p<0.05). CD4+CD25+ Foxp3+ Treg cells were also significantly increased in RCCC patients (p<0.05). Cox multivariate regression analysis showed that MEKK3, pERK expression and patholigical stage were independent prognostic factors in patients with RCCC (p<0.05). MEKK3 can be used as an important marker of early diagnosis and prognostic evaluation in RCCC. It may be associated with imbalance of anti-tumor immunity and overexpression of pERK. Expression of MEKK3 and pERK are significantly increased in RCCC, with protein expression and clinical stage acting as independent prognostic factors.

Growth of Human Colon Cancer Cells in Nude Mice is Delayed by Ketogenic Diet With or Without Omega-3 Fatty Acids and Medium-chain Triglycerides

Hao, Guang-Wei,Chen, Yu-Sheng,He, De-Ming,Wang, Hai-Yu,Wu, Guo-Hao,Zhang, Bo Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.5

Background: Tumors are largely unable to metabolize ketone bodies for energy due to various deficiencies in one or both of the key mitochondrial enzymes, which may provide a rationale for therapeutic strategies that inhibit tumor growth by administration of a ketogenic diet with average protein but low in carbohydrates and high in fat. Materials and Methods: Thirty-six male BALB/C nude mice were injected subcutaneously with tumor cells of the colon cancer cell line HCT116. The animals were then randomly split into three feeding groups and fed either a ketogenic diet rich in omega-3 fatty acids and MCT (MKD group; n=12) or lard only (LKD group; n=12) or a standard diet (SD group; n=12) ad libitum. Experiments were ended upon attainment of the target tumor volume of $600mm^3$ to $700mm^3$. The three diets were compared for tumor growth and survival time (interval between tumor cell injection and attainment of target tumor volume). Results: The tumor growth in the MKD and LKD groups was significantly delayed compared to that in the SD group. Conclusions: Application of an unrestricted ketogenic diet delayed tumor growth in a mouse xenograft model. Further studies are needed to address the mechanism of this diet intervention and the impact on other tumor-relevant parameters such as invasion and metastasis.

Dynamic mechanism of HIV replication inhibitor peptide encapsulated into carbon nanotubes

Bao-Dong Chen,Chuan-Lu Yang,Jun-Sheng Yang,Mei-Shan Wang,Xiao-Guang Ma 한국물리학회 2013 Current Applied Physics Vol.13 No.6

Biomolecules encapsulated in carbon nanotubes (CNTs) have attracted much interest and facilitated exciting opportunities for biological and biomedical applications of CNTs. Understanding the fundamental interaction and change in biomolecules during encapsulation is indispensable but remains a challenge for both theoretical and experimental investigations. This paper focuses on the interaction between HIV replication inhibitor peptide (HRIP) and CNTs in a neutral solution with molecular dynamics simulation. We observed that HRIP spontaneously inserts into the CNTs and oscillates around the center of the tube, where the non-covalent interaction is minimum. The effects of the diameters of the CNTs on HRIP were investigated. The optimal diameter of the CNT that can provide the most effective encapsulation and causes minimum conformational change in HRIP was found. The present results provide valuable insights in the understanding of nanoscale drug delivery using CNT-based devices.

Percutaneous ablation of liver metastases from colorectal cancer: a comparison between the outcomes of ultrasound guidance and CT guidance using propensity score matching

Ma Luo,Sheng Peng,Guang Yang,Letao Lin,Ligong Lu,Jiawen Chen,Fujun Zhang,Fei Gao 대한초음파의학회 2023 ULTRASONOGRAPHY Vol.42 No.1

Purpose: The aim of this study was to compare the effectiveness and outcomes of percutaneous ablation guided by ultrasonography (US) and computed tomography (CT) in colorectal liver oligometastases (CLOM). Methods: This study included patients with CLOM treated with percutaneous ablation from January 2008 to January 2021 in this observational study. Only lesions visualized on both CT and US images were further analyzed according to whether patients’ initial ablation treatments utilized US guidance or CT guidance. The Kaplan-Meier method was used to estimate local tumor progression (LTP)–free survival after propensity score matching (PSM). The LTP-free survival and treatment-related outcomes were compared between these two groups. Results: PSM identified 116 patients from each group, with 269 and 238 lesions in the USguided and CT-guided groups, respectively. US-guided ablation had a shorter average procedure time and lower cost than CT-guided ablation (27.54±12.06 minutes vs. 32.70±13.88 minutes, P=0.003; $2,175.13±618.17 vs. $2,455.49±710.25, P=0.002). For patients >60 years of age, the cumulative LTP rate at 1 year was lower in the US-guided group than in the CT-guided group (17.8% vs. 25.1%, P=0.038). For patients with perivascular liver lesions, the cumulative LTP rate at 1 year was lower in the US-guided group (14.4% vs. 28.2%, P=0.040). Conclusion: For patients whose age is >60 years or who have perivascular liver lesions, USguided ablation is better than CT-guided ablation, with a shorter treatment time and lower costs when both ablation methods are feasible for patients.

Detection of PCB77 by Indirect Competitive Enzyme-linked Immunosorbent Assay in Sea Sediment Samples

Han-Yu Chen,Hui-Sheng Zhuang,Guang-Xin Yang 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.3

3,3',4,4'-Tetrachlorobiphenyl (IUPAC PCB77) is one of seven indicative polychlorinated biphenyls (PCBs) in the surface sediments. The current study presents a novel polyclonal antibody for the determination of the PCB77 using indirect competitive enzyme-linked immunosorbent assay. Under optimum conditions, PCB77 was determined within the concentration range of 0.01-100 μg L–1, with a detection limit of 0.057 μg L–1. The assays were tested for their cross-reactivity profiles using 3 selected congeners and 4 Aroclor products. The assays were highly specific for coplanar PCB congeners, but less specific for Aroclor1248. The spiked recoveries from five sediment samples were 86%-114% for PCB77 from ELISA, which were satisfactory. The current study demonstrated that the developed antiserum and immunoassay procedure can be used to detect PCB77 in environmental samples. The results of the sediment analysis were confirmed by conventional GC/ ECD.

Investigation of polymeric amphiphilic nanoparticles as antitumor drug carriers

Zhang, Jing,Chen, Xi Guang,Liu, Cheng Sheng,Park, Hyun Jin Springer-Verlag 2009 Journal of materials science, Materials in medicin Vol.20 No.4