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.

Characterizations on Knee Movement Estimation from Surface EMG Using Composited Approaches

Hui-Bin Li,Zhong Li,Xiao-Rong Guan 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.1

This paper focuses on the relationship between surface electromyography (sEMG) signals and knee joint movement which would be applied in the extra assistant robotic legs (EARL). The characterizations of the sEMG data group for movement estimation were analyzed depending on the composited approaches, which were analyzed in situations of diferent sample sizes, diferent muscle groups, diferent time-domain features, and diferent algorithms. According to the analysis of knee movement estimation, it can be found that (1) Increasing the sample size, and the estimation accuracy becomes better. (2) The vastus lateralis and gastrocnemius lateralis have larger activation than the vastus medialis and gastrocnemius medialis, but the estimation accuracy is worse. (3) The estimation accuracy of time-domain features is related to the complexity of the feature group, the range of average AR2 is 0.86 to 0.92. (4) The composited algorithms are better than a single back propagation neural network (BPNN), and principal component analysis is ftter than independent component analysis in conjunction with BPNN for estimation. This study reveals the hind factors that people cannot square up while extracting and processing the sEMG signals. This study’s results can help build new training data to improve the estimation accuracy of knee movement for sEMG.

Microstructural Evolution and Dynamic Recrystallization Behavior of the Homogenized 2195 Al–Li Alloy During Hot Deformation

Rong Fu,Yuanchun Huang,Yu Liu,Hui Li 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.9

The thermal deformation behavior in homogenized 2195 Al–Li alloy was studied at different deformation temperatures(370–520 °C and strain rates (0.001–1 s−1). The flow stress decreases with decreasing strain rate or increasing temperature. The significant decrease in flow stress from 370 to 420 °C is related to the fact that movements of dislocations and (sub)grain boundaries at low temperatures are hindered by the dynamic precipitation of numerous fine secondary phases (mainlyAl2CuLi(T1) phases). Meanwhile, it was found that flow localization regions appear in the microstructure at 370 °C/1 s−1. Besides, DRX and DRV increase with decreasing lnZ (Zener–Hollomon parameter) values, particularly for lnZ values lessthan 26.32 (520 °C/0.1 s−1). The DRX mechanism was discussed for different lnZ based on the variation of misorientationangle and the characteristics of different DRXs. The DDRX is dominant when lnZ ≥ 30.70; CDRX and DDRX dominate at30.70 > lnZ > 26.32; CDRX mainly occurs at lnZ ≤ 26.32; when lnZ value decreases to 21.72, DRX grains with the characteristicsof CDRX and GDRX appear.

Crocetin Induces Cytotoxicity in Colon Cancer Cells Via p53-independent Mechanisms

Li, Cai-Yan,Huang, Wen-Feng,Wang, Qun-Li,Wang, Fan,Cai, E.,Hu, Bing,Du, Jia-Cheng,Wang, Jing,Chen, Rong,Cai, Xiao-Jing,Feng, Jing,Li, Hui-Hui Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.8

Objective: Crocin has been proposed as a promising candidate for cancer chemoprevention. The purpose of this investigation was to investigate the chemopreventive action and the possible mechanisms of crocin against human colon cancer cells in vitro. Methods: Cell proliferation was examined using MTT assay and the cell cycle distribution fractions were analyzed using fow cytometric analysis after propidium iodide staining. Apoptosis was detected using theTUNEL Apoptosis Detection Kit with laser scanning confocal microscope. DNA damage was assessed using the alkaline single-cell gel electrophoresis assay, while expression levels of p53, cdk2, cyclinA and P21 were examined by Western blot analysis. Results: Treatment of SW480 cells with crocetin (0.2, 0.4, 0.8 mmol/L) for 48 h signifcantly inhibited their proliferation in a concentration-dependent manner. Crocetin (0.8 mmol/L) signifcantly induced cell cycle arrest through p53-independent mechanisms accompanied by P21 induction. Crocetin (0.8 mmol/L) caused cytotoxicity in the SW480 cells by enhancing apoptosis and decreasing DNA repair capacity in a time-dependent manner. Conclusions: This report provides evidence that crocetin is a potential anticancer agent, which may be used as a chemotherapeutic drug.

Monosaccharide as a Central Scaffold Toward the Construction of Salicylate-Based Bidentate PTP1B Inhibitors via Click Chemistry

Yan-Hui Tang,Min Hu,Xiao-Peng He,Sando Fahnbulleh,Cui Li,Li-Xin Gao,Li Sheng,Yun Tang,Jia Li,Guo-Rong Chen 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.3

The discovery of carbohydrate-based bioactive compounds has recently received considerable interest in the drug development. This paper stresses on the application of 1-methoxy-O-glucoside as the central scaffold,whereas salicylic pharmacophores were introduced with diverse spatial orientations probing into the structural preference of an enzymatic target, i.e. protein tyrosine phosphatase 1B (PTP1B). By employing regioselective protection and deprotection strategy, 2,6-, 3,4-, 4,6- and 2,3-di-O-propynyl 1-methoxy-O-glucosides were previously synthesized and then coupled with azido salicylate via click chemistry in forming the desired bidentate salicylic glucosides with high yields. The inhibitory assay of the obtained triazolyl derivatives leads to the identification of the 2,3-disubstituted salicylic 1-methoxy-O-glucoside as the structurally privileged PTP1B inhibitor among this bidentate compound series with micromole-ranged IC50 value and reasonable selectivity over other homologous PTPs tested. In addition, docking simulation was conducted to propose a plausible binding mode of this authorized inhibitor with PTP1B. This research might furnish new insight toward the construction of structurally different bioactive compounds based on the monosaccharide scaffold.

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.

A Multi-center Survey of HPV Knowledge and Attitudes Toward HPV Vaccination among Women, Government Officials, and Medical Personnel in China

Zhao, Fang-Hui,Tiggelaar, Sarah M.,Hu, Shang-Ying,Zhao, Na,Hong, Ying,Niyazi, Mayinuer,Gao, Xiao-Hong,Ju, Li-Rong,Zhang, Li-Qin,Feng, Xiang-Xian,Duan, Xian-Zhi,Song, Xiu-Ling,Wang, Jing,Yang, Yun,Li, Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.5

Objectives: To assess knowledge of HPV and attitudes towards HPV vaccination among the general female population, government officials, and healthcare providers in China to assist the development of an effective national HPV vaccination program. Methods: A cross-sectional epidemiologic survey was conducted across 21 urban and rural sites in China using a short questionnaire. 763 government officials, 760 healthcare providers, and 11,681 women aged 15-59 years were included in the final analysis. Data were analyzed using standard descriptive statistics and logistic regression. Results: Knowledge of HPV among the general female population was low; only 24% had heard of HPV. Less than 20% of healthcare providers recognized sexually na$\ddot{i}$ve women as the most appropriate population for HPV vaccination. There was high acceptance of the HPV vaccine for all categories of respondents. Only 6% of women were willing to pay more than US $300 for the vaccine. Conclusions: Aggressive education is necessary to increase knowledge of HPV and its vaccine. Further proof of vaccine safety and efficacy and government subsidies combined with increased awareness could facilitate development and implementation of HPV vaccination in China.

Monosaccharide as a Central Scaffold Toward the Construction of Salicylate-Based Bidentate PTP1B Inhibitors via Click Chemistry

Tang, Yan-Hui,Hu, Min,He, Xiao-Peng,Fahnbulleh, Sando,Li, Cui,Gao, Li-Xin,Sheng, Li,Tang, Yun,Li, Jia,Chen, Guo-Rong Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.3

The discovery of carbohydrate-based bioactive compounds has recently received considerable interest in the drug development. This paper stresses on the application of 1-methoxy-O-glucoside as the central scaffold, whereas salicylic pharmacophores were introduced with diverse spatial orientations probing into the structural preference of an enzymatic target, i.e. protein tyrosine phosphatase 1B (PTP1B). By employing regioselective protection and deprotection strategy, 2,6-, 3,4-, 4,6- and 2,3-di-O-propynyl 1-methoxy-O-glucosides were previously synthesized and then coupled with azido salicylate via click chemistry in forming the desired bidentate salicylic glucosides with high yields. The inhibitory assay of the obtained triazolyl derivatives leads to the identification of the 2,3-disubstituted salicylic 1-methoxy-O-glucoside as the structurally privileged PTP1B inhibitor among this bidentate compound series with micromole-ranged $IC_{50}$ value and reasonable selectivity over other homologous PTPs tested. In addition, docking simulation was conducted to propose a plausible binding mode of this authorized inhibitor with PTP1B. This research might furnish new insight toward the construction of structurally different bioactive compounds based on the monosaccharide scaffold.

Clinical Efficacy of Bevacizumab Concomitant with Pemetrexed in Patients with Advanced Non-small Cell Lung Cancer

Zhang, Yu-Mei,Li, Yong-Qiang,Liu, Zhi-Hui,Liao, Xiao-Li,Liang, Rong,Lin, Yan,Yuan, Chun-Ling,Liao, Si-Na,Liang, Chao-Yong,Li, Qian,Li, Le-Qun Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.8

Objective: To observe the clinical efficacy of bevacizumab concomitant with pemetrexed in patients with advanced non-small cell lung cancer (NSCLC). Materials and Methods: A total of 72 patients were randomly divided into a combination group (pemetrexed+bevacizumab, n=36) and a pemetrexed group (n=36) and assessed for disease control (CR+PR+SD) after 4-cycles of first-line GP chemotherapy (gemcitabine+cisplatin). Clinical efficacy, progression-free survival time (PFS), overall survival time (OS), overall response rate (ORR), disease control rate (DCR) and rate of adverse responses between two groups were observed and compared. Results: ORR and DCR were 27.8% and 83.4% in combination group, and 16.7% and 69.5% in the pemetrexed group, respectively, but there were no significant differences (P>0.05). PFS in combination group and pemetrexed group were 4.6 months and 3.9 months respectively (P=0.09), whereas OS in the combination group was 14 months, evidently higher than in the pemetrexed group (11 months, P=0.004). Adverse responses in both groups included high blood pressure, bleeding, thrombocytopenia, anemia, elevated transaminase, diarrhea, vomiting and proteinuria, but there were no significant differences (P>0.05). Conclusions: Bevacizumab concomitant with pemetrexed has better clinical efficacy and safety, giving rise to prolonged survival time in patients with advanced NSCLC.

Age of Diagnosis of Breast Cancer in China: Almost 10 Years Earlier than in the United States and the European Union

Song, Qing-Kun,Li, Jing,Huang, Rong,Fan, Jin-Hu,Zheng, Rong-Shou,Zhang, Bao-Ning,Zhang, Bin,Tang, Zhong-Hua,Xie, Xiao-Ming,Yang, Hong-Jian,He, Jian-Jun,Li, Hui,Li, Jia-Yuan,Qiao, You-Lin,Chen, Wan-Qin Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.22

Background: The study aimed to describe the age distribution of breast cancer diagnosis among Chinese females for comparison with the United States and the European Union, and provide evidence for the screening target population in China. Materials and Methods: Median age was estimated from hospital databases from 7 tertiary hospitals in China. Population-based data in China, United States and European Union was extracted from the National Central Cancer Registry, SEER program and GLOBOCAN 2008, respectively. Age-standardized distribution of breast cancer at diagnosis in the 3 areas was estimated based on the World Standard Population 2000. Results: The median age of breast cancer at diagnosis was around 50 in China, nearly 10 years earlier than United States and European Union. The diagnosis age in China did not vary between subgroups of calendar year, region and pathological characteristics. With adjustment for population structure, median age of breast cancer at diagnosis was 50~54 in China, but 55~59 in United States and European Union. Conclusions: The median diagnosis age of female breast cancer is much earlier in China than in the United States and the European Union pointing to racial differences in genetics and lifestyle. Screening programs should start at an earlier age for Chinese women and age disparities between Chinese and Western women warrant further studies.