Properties of a CdZnO/ZnO Multiple Quantum-Well Light-Emitting Diode

Zhan-Hui Liu,Li-Li Zhang,Qing-Fang Li,Rong Zhang,Zi-Li Xie,Xiang-Qian Xiu,Bin Liu 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.69 No.7

A CdZnO/ZnO multiple quantum-well light-emitting diode (LED) structure was successfully grown by using plasma-assisted molecular beam epitaxy on a p-GaN template that had been grown by using metal-organic chemical-vapor deposition on a c-sapphire substrate. The properties of the sample were characterized by using high-resolution X-ray diffraction, transmission electron microscopy, and temperature-dependent photoluminescence measurements. The light output performance of the CdZnO/ZnO QW LED device was also investigated in detail by using I-V and electroluminescence spectral measurements. The characterization showed that our CdZnO/ZnO QW LED structure had good crystalline quality and weaker carrier localization. Owing to the heterojunction structure, the I-V curve indicated that the LED device had a higher turn-on voltage and series resistance. The EL measurement demonstrated that for our LED device’s optoelectronic characteristic, the carrier-screening effect played the dominant role in the emission-energy blue-shift mechanism, and the broadening of the emission energy width was mainly ascribed to the band-filling effect. Without a special heat sinking, the L-I curve exhibited slight efficiency droop after 30 mA.

Growth Inhibition and Apoptosis Induction of Human Umbilical Vein Endothelial Cells by Apogossypolone

Zhan, Yong-Hua,Huang, Xiao-Feng,Hu, Xing-Bin,An, Qun-Xing,Liu, Zhi-Xin,Zhang, Xian-Qing Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.3

Aims and Background: Prostate cancer is one of the most common malignant tumors in the male reproductive system, which causes the second most cancer deaths of males, and control of angiogenesis in prostate lesions is of obvious importance. This study assessed the effect of apogossypolone (ApoG2) on proliferation and apoptosis of human umbilical vein endothelial cells (HUVECs). Subjects and Methods: HUVECs were treated with different concentrations of ApoG2. The survival rate of HUVECs were determined by MTT assay. Utrastructural changes of HUVECs were assessed with transmission electron microscopy. Apoptosis in HUVECs was analyzed by flow cytometry and cell migration by Boyden chamber assay. Matrigel assays were used to quantify the development of tube-like networks. Results: ApoG2 significantly inhibited HUVEC growth even at 24 h (P<0.05). The inhibitory effect of ApoG2 is more obvious as the concentration and the culture time increased (P<0.05). These results indicate that ApoG2 inhibits the proliferation of HUVECs in a time- and concentration-dependent manner with increase of the apoptosis rate. Besides, ApoG2 reduced the formation of total pseudotubule length and network branches of HUVECs. Conclusions: The results suggest that ApoG2 inhibits angiogenesis of HUVECs by growth inhibition and apoptosis induction.

Performance of Hepatitis B Core-Related Antigen Versus Hepatitis B Surface Antigen and Hepatitis B Virus DNA in Predicting HBeAg-positive and HBeAg-negative Chronic Hepatitis

Zhan-qing Zhang,Yan-bing Wang,,Wei Lu,,Dan-ping Liu,,Bi-sheng Shi,,Xiao-nan Zhang,,Dan Huang,,Xiu-fen Li,,Xin-lan Zhou,,Rong-rong Ding, 대한진단검사의학회 2019 Annals of Laboratory Medicine Vol.39 No.1

Background: We examined changes in hepatitis B core-related antigen (HBcrAg) during the four sequential phases of chronic hepatitis B virus (HBV) infection: hepatitis B e antigen (HBeAg)-positive chronic infection (EPCI) and hepatitis (EPCH), followed by HBeAg-negative chronic infection (ENCI) and hepatitis (ENCH). We compared the performance of serum HBcrAg, hepatitis B surface antigen (HBsAg), and HBV DNA in predicting EPCH and ENCH.

Gamma and X-ray irradiation as a phytosanitary treatment against various stages of Planococcus lilacinus (Hemiptera: Pseudococcidae)

Ma Chen,Liu Hui,Liu Bo,Zhao Ju-Peng,Zhao Qing-Ying,Song Zi-Jiao,Han Xin,Zhan Guo-Ping 한국응용곤충학회 2022 Journal of Asia-Pacific Entomology Vol.25 No.4

The cacao mealybug, Planococcus lilacinus Cock, is an important quarantine pest. Infested commodity should be subject to appropriate phytosanitary treatment, while irradiation is recommended for the cacao mealybug. Radio-tolerance comparison tests were conducted on the crawler, nymphs, and adult females of P. lilacinus at the X-ray radiation doses of 40, 80, and 120 Gy, respectively. The results showed that irradiation had a strong effect on preventing of development and reproduction; the adult female stage was identified as the most tolerant. During the following dose–response tests, among young and late females X-ray-irradiation (20–100 Gy), the late females were most tolerant when preventing F 1 generation 2nd instars emergence was used as the evaluation criterion. Minimum absorbed dose and its 95 % fiducial limits to provide probit 9 efficacy at 95 % confidence level (100 % mortality/inhibition in an estimated population of 93,616 individuals) were 131.5 Gy (122.5, 142.6 Gy) and 144.4 Gy (132.7, 159.4 Gy), estimating from the probit analysis on dose-mortality data of 1–30 and 1–10-day-old neonates laid by late females, respectively. In the large-scale confirmatory tests, a total of estimating 97,384 late females of P. lilacinus rearing on the pumpkins fruits were irradiated with gamma-ray at the target dose of 135 or 145 Gy (measured doses 126.1–163.0 Gy), which resulted in no F 1 generation 2nd nymphs developing during a 6-week post-treatment period. The treatment efficacy calculated is 99.9969 % at the 95 % confidence level. Therefore, a minimum absorbed dose of 163.0 Gy is recommended for phytosanitary treatment of P. lilacinus in infested commodity.

Combination of FDG PET/CT and Contrast-Enhanced MSCT in Detecting Lymph Node Metastasis of Esophageal Cancer

Tan, Ru,Yao, Shu-Zhan,Huang, Zhao-Qin,Li, Jun,Li, Xin,Tan, Hai-Hua,Liu, Qing-Wei Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.18

Background: Lymph node metastasis is believed to be a dependent negative prognostic factor of esophageal cancer. To explore detection methods with high sensitivity and accuracy for metastases to regional and distant lymph nodes in the clinic is of great significance. This study focused on clinical application of FDG PET/CT and contrast-enhanced multiple-slice helical computed tomography (MSCT) in lymph node staging of esophageal cancer. Materials and Methods: One hundred and fifteen cases were examined with enhanced 64-slice-MSCT scan, and FDG PET/CT imaging was conducted for neck, chest and upper abdomen within one week. The primary lesion, location and numbers of metastatic lymph nodes were observed. Surgery was performed within one week after FDG PET/CT detection. All resected lesions were confirmed histopathologically as the gold standard. Comparative analysis of the sensitivity, specificity, and accuracy based on FDG PET/CT and MSCT was conducted. Results: There were 946 lymph node groups resected during surgery from 115 patients, and 221 were confirmed to have metastasis pathologically. The sensitivity, specificity, accuracy of FDG PET/CT in detecting lymph node metastasis were 74.7%, 97.2% and 92.0%, while with MSCT they were 64.7%, 96.4%, and 89.0%, respectively. A significance difference was observed in sensitivity (p=0.030), but not the others (p>0.05). The accuracy of FDG PET/CT in detecting regional lymph node with or without metastasis were 91.9%, as compared to 89.4% for MSCT, while FDG PET/CT and MSCT values for detecting distant lymph node with or without metastasis were 94.4% and 94.7%. No significant difference was observed for either regional or distant lymph node metastasis. Additionally, for detecting para-esophageal lymph nodes metastasis, the sensitivity of FDG PET/CT was 72%, compared with 54.7% for MSCT (p=0.029). Conclusions: FDG PET/CT is more sensitive than MSCT in detecting lymph node metastasis, especially for para-esophageal lymph nodes in esophageal cancer cases, although no significant difference was observed between FDG PET/CT and MSCT in detecting both regional and distant lymph node metastasis. However, enhanced MSCT was found to be of great value in distinguishing false negative metastatic lymph nodes from FDG PET/CT. The combination of FDG PET/CT with MSCT should improve the accuracy in lymph node metastasis staging of esophageal cancer.

Interspecies Transfer and Regulation of Pseudomonas stutzeri A1501 Nitrogen Fixation Island in Escherichia coli

( Yunlei Han ),( Na Lu ),( Qing Hua Chen ),( Yu Hua Zhan ),( Wei Liu ),( Wei Lu ),( Bao Li Zhu ),( Min Lin ),( Zhi Rong Yang ),( Yong Liang Yan ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.8

Until now, considerable effort has been made to engineer novel nitrogen-fixing organisms through the transfer of nif genes from various diazotrophs to non-nitrogen fixers; however, regulatory coupling of the heterologous nif genes with the regulatory system of the new host is still not well understood. In this work, a 49 kb nitrogen fixation island from P. stutzeri A1501 was transferred into E. coli using a novel and efficient transformation strategy, and a series of recombinant nitrogen-fixing E. coli strains were obtained. We found that the nitrogenase activity of the recombinant E. coli strain EN-01, similar to the parent strain P. stutzeri A1501, was dependent on external ammonia concentration, oxygen tension, and temperature. We further found that there existed a regulatory coupling between the E. coli general nitrogen regulatory system and the heterologous P. stutzeri nif island in the recombinant E. coli strain. We also provided evidence that the E. coli general nitrogen regulator GlnG protein was involved in the activation of the nif-specific regulator NifA via a direct interaction with the NifA promoter. To the best of our knowledge, this work plays a groundbreaking role in increasing understanding of the regulatory coupling of the heterologous nitrogen fixation system with the regulatory system of the recipient host. Furthermore, it will shed light on the structure and functional integrity of the nif island and will be useful for the construction of novel and more robust nitrogen-fixing organisms through biosynthetic engineering.

Tri-stimuli responsive carbon nanotubes covered by mesoporous silica graft copolymer multifunctional materials for intracellular drug delivery

Rui-Qian Zhang,Zhan-Qing Liu,Yan-Ling Luo,Feng Xu,Ya-Shao Chen 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.80 No.-

To overcome premature drug leakage and instability in drug delivery systems, we designed tri-stimuliresponsive multiwalled carbon nanotubes covered by mesoporous silica graft poly(N-isopropylacryla-mide-block-poly(2-(4-formylbenzoyloxy) ethyl methacrylate) multifunctional materials via disulfidelinkages (MWCNTs@MSN-s-s-g-PNIPAM-b-PFBEMA). The multifunctional materials could covalentlybind and physically load anticancer drug doxorubicin (DOX), and exhibited pH-, temperature- andreductant-induced multi-stimuli responsiveness, significantly enhancing drug loading capacity andimproving the release dynamics of drug. The DOX-loaded multifunctional materials exhibited theoptimal release behavior in cancer environments compared with in normal cells upon simultaneouslytriggered by these stimuli. It meant that the MWCNTs@MSN-s-s-g-PNIPAM-b-PFBEMA could serve asefficient gatekeepers to control the mesopore on–off and thus to modulate drug release. Themultifunctional materials were proved to be low toxic, whereas the DOX-loaded counterparts had almostthe same toxicity as free DOX to cancer cells. Therefore, the developed multifunctional materials can beused as promising drug controlled delivery platforms for cancer therapy.

Properties of an AlGaN/AlN Distributed-Bragg-reflector Structure

Li-Li Zhang,Zhan-Hui Liu,Xiao-Gu Huang,Qing-Fang Li,Rong Zhang,Zi-Li Xie,Xiang-Qian Xiu 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.65 No.7

An AlGaN/AlN distributed-Bragg-reflector (DBR) structure with a high Al content was grown byusing plasma-assisted molecular beam epitaxy (PA-MBE). The properties of the sample were characterizedby using the transmission electron microscopy, high-resolution X-ray diffraction, atomicforce microscopy, and reflectivity spectrum measurements. The reciprocal space mapping analysisindicated that the strain in the AlGaN layers was partially relaxed. The morphology of the DBRexhibited a surface covered by grains (average size of about 130 nm), and the surface roughness wasabout 2 nm. The spectral measurements showed that the DBR structure presented a peak reflectivityof 68.8% at the center wavelength of 247 nm, which indicated that this DBR structure couldwork in the deep solar-blind UV region with acceptable reflectivity. However, the optical propertiesof the DBR structure were deteriorated by the fluctuation of the Al composition, non-uniformity ofthe layer thickness, the blurry, rough interface in the DBR structure, and so on.

Expression HpaG(Xooc) Protein in Bacillus subtilis and its Biological Functions

( Hui Jun Wu ),( Shuai Wang ),( Jun Qing Qiao ),( Jun Liu ),( Jiang Zhan ),( Xue Wen Gao ) 한국미생물 · 생명공학회 2009 Journal of microbiology and biotechnology Vol.19 No.2

Targeting EGFL7 Expression through RNA Interference Suppresses Renal Cell Carcinoma Growth by Inhibiting Angiogenesis

Xu, Han-Feng,Chen, Lei,Liu, Xian-Dong,Zhan, Yun-Hong,Zhang, Hui-Hui,Li, Qing,Wu, Bin Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.7

Renal cell carcinoma (RCC) is the most lethal of all urological cancers and tumor angiogenesis is closely related with its growth, invasion, and metastasis. Recent studies have suggested that epidermal growth factor-like domain multiple 7 (EGFL7) is overexpressed by many tumors, such as colorectal cancer and hepatocellular carcinoma; it is also correlated with progression, metastasis, and a poor prognosis. However, the role of EGFL7 in RCC is not clear. In this study, we examined how EGFL7 contributes to the growth of RCC using a co-culture system in vitro and a xenograft model in vivo. Downregulated EGFL7 expression in RCC cells affected the migration and tubule formation of HMEC-1 cells, but not their growth and apoptosis in vitro. The level of focal adhesion kinase (FAK) phosphorylation in HMEC-1 cells decreased significantly when co-cultured with 786-0/iEGFL7 cells compared with 786-0 cells. After adding rhEGFL7, the level of FAK phosphorylation in HMEC-1 cells was significantly elevated compared with phosphate-buffered saline (PBS) control. However, FAK phosphorylation was abrogated by EGFR inhibition. The average size of RCC local tumors in the 786-0/iEGFL7 group was noticeably smaller than those in the 786-0 cell group and their vascular density was also significantly decreased. These data suggest that EGFL7 has an important function in the growth of RCC by facilitating angiogenesis.