Theoretical Studies on Electronic Structure and Absorption Spectrum of Prototypical Technetium-Diphosphonate Complex ^(99m)Tc-MDP

Ling Qiu,Jian-Guo Lin,Shi-Neng Luo,Xue-Dong Gong,Xue-Hai Ju 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.7

Density functional theory (DFT) and time-dependent density functional theory (TDDFT) calculations,employing the B3LYP method and the LANL2DZ, 6-31G^*(LANL2DZ for Tc), 6-31G^*(cc-pVDZ-pp for Tc)and DGDZVP basis sets, have been performed to investigate the electronic structures and absorption spectra of the technetium-99m-labeled methylenediphosphonate (^(99m)Tc-MDP) complex of the simplest diphosphonate ligand. The bonding situations and natural bond orbital compositions were studied by the Mulliken population analysis (MPA) and natural bond orbital (NBO) analysis. The results indicate that the σ and π contributions to the Tc-O bonds are strongly polarized towards the oxygen atoms and the ionic contribution to the Tc-O bonding is larger than the covalent contribution. The electronic transitions investigated by TDDFT calculations and molecular orbital analyses show that the origin of all absorption bands is ascribed to the ligand-to-metal charge transfer (LMCT) character. The solvent effect on the electronic structures and absorption spectra has also been studied by performing DFT and TDDFT calculations at the B3LYP/6-31G^*(cc-pVDZ-pp for Tc) level with the integral equation formalism polarized continuum model (IEFPCM) in different media. It is found that the absorption spectra display blue shift in different extents with the increase of solvent polarity.

Melting and crystallization behaviors of compatibilized poly(trimethylene terephthalate)/acrylonitrile–butadiene–styrene blends

Xue, Mei-Ling,Yu, Yong-Liang,Chuah, Hoe H.,Rhee, John M.,Lee, Joong Hee Wiley Subscription Services, Inc., A Wiley Company 2008 Journal of applied polymer science Vol.108 No.5

<P>The melting and crystallization behaviors of poly(trimethylene terephthalate) (PTT)/acrylonitrile–butadiene–styrene (ABS) blends were investigated with and without epoxy or styrene–butadiene–maleic anhydride copolymer (SBM) as a reactive compatibilizer. The existence of two separate composition-dependent glass-transition temperatures (T<SUB>g</SUB>'s) indicated that PTT was partially miscible with ABS over the entire composition range. The melting temperature of the PTT phase in the blends was also composition dependent and shifted to lower temperatures with increasing ABS content. Both the cold crystallization temperature and T<SUB>g</SUB> of the PTT phase moved to higher temperatures in the presence of compatibilizers, which indicated their compatibilization effects on the blends. A crystallization exotherm of the PTT phase was noticed for all of the PTT/ABS blends. The crystallization behaviors were completely different at low and high ABS contents. When ABS was 0–50 wt %, the crystallization process of PTT shifted slightly to higher temperatures as the ABS content was increased. When ABS was 60 wt % or greater, PTT showed fractionated crystallization. The effects of both the epoxy and SBM compatibilizers on the crystallization of PTT were content dependent. At a lower contents of 1–3 wt % epoxy or 1 wt % SBM, the crystallization was retarded, whereas at a higher content of 5 wt %, the crystallization was accelerated. The crystallization kinetics were analyzed with a modified Avrami equation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008</P>

Refined numerical simulation in wind resource assessment

Xue-Ling Cheng,Jun Li,Fei Hu,Jingjing Xu,Rong Zhu 한국풍공학회 2015 Wind and Structures, An International Journal (WAS Vol.20 No.1

A coupled model system for Wind Resource Assessment (WRA) was studied. Using a mesoscale meteorological model, the Weather Research and Forecasting (WRF) model, global-scale data were downscaled to the inner nested grid scale (typically a few kilometers), and then through the coupling Computational Fluid Dynamics (CFD) mode, FLUENT. High-resolution results (50 m in the horizontal direction; 10 m in the vertical direction below 150 m) of the wind speed distribution data and ultimately refined wind farm information, were obtained. The refined WRF/FLUENT system was then applied to assess the wind resource over complex terrain in the northern Poyang Lake region. The results showed that the approach is viable for the assessment of wind energy.

Study on Soil Eco-hydrological Function during the Degradation Process of Mountain Meadow

Zhang Xue-Ling,Guo Xiao-Min,Niu De-Kui,Zhang Wen-Yuan,Li Zhi 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

The high Curie temperature and long-range ferromagnetism in Mn-doped 3C-SiC: a study using first-principles calculation

Lin Xue-ling,Zhang He-xiang,Yang Wei-xia,Chen Huan-ming,Pan Feng-chun 한국물리학회 2021 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.79 No.6

Magnetic semiconductors with high Curie temper (TC) and inherent ferromagnetism, which not only provide a data-processing function via semiconductors’ properties, but also offer a data-storage function through intrinsic ferromagnetism, have become key materials in the field of spintronics. We studied the electronic structures and magnetic properties of Mn-doped cubic (3C) SiC using first-principles calculation. The calculated results revealed that MnSi and MnC substitutions can introduce 3 μB and 1 μB magnetic moments into SiC, respectively, which are both localized and extended. The extended tails of the moments indicate a significant spatial extension of the spin-polarized electron states. The interaction between the long tails, which can mediate long-range ferromagnetic (FM) coupling up to 8.55 Å, and is very different from common exchange, in which the ferromagnetism decreases sharply with increasing distance between the moments, and is hard to maintain to the next-neighbor order due to the limited spatial spin-electrons distribution. The distributions of magnetic moments become more and more localized or extended as compressive or tensile strains are increased, but FM interactions under compressive and tensile strains are weaker than those in undeformed structure. The FM coupling mechanism is explained and discussed in detail using p–d electron exchange. These results can provide a routine for engineering FM semiconductor of 3C-SiC.

Refined numerical simulation in wind resource assessment

Cheng, Xue-Ling,Li, Jun,Hu, Fei,Xu, Jingjing,Zhu, Rong Techno-Press 2015 Wind and Structures, An International Journal (WAS Vol.20 No.1

A coupled model system for Wind Resource Assessment (WRA) was studied. Using a mesoscale meteorological model, the Weather Research and Forecasting (WRF) model, global-scale data were downscaled to the inner nested grid scale (typically a few kilometers), and then through the coupling Computational Fluid Dynamics (CFD) mode, FLUENT. High-resolution results (50 m in the horizontal direction; 10 m in the vertical direction below 150 m) of the wind speed distribution data and ultimately refined wind farm information, were obtained. The refined WRF/FLUENT system was then applied to assess the wind resource over complex terrain in the northern Poyang Lake region. The results showed that the approach is viable for the assessment of wind energy.

Identification of a Novel Streptomyces chattanoogensis L10 and Enhancing Its Natamycin Production by Overexpressing Positive Regulator ScnRII

Yi-Ling Du,Shi-Fei Chen,Liang-Ying Cheng,Xue-Ling Shen,Yuan Tian,Yong-Quan Li 한국미생물학회 2009 The journal of microbiology Vol.47 No.4

A novel Streptomyces strain, L10, which is capable of producing natamycin, was isolated from a soil sample collected from Zhejiang province, China. On the basis of phylogenetic analysis of rpoB gene and 16S rDNA sequences, as well as phenotypic comparison, strain L10 (CGMCC 2644) is proposed to be a previously uncharacterized strain of S. chattanoogensis. By screening a cosmid library of strain L10 and primer walking, a partial sequence of scnRI and the entire sequence of scnRII were obtained, which are orthologues to the pathway-specific positive regulator genes of natamycin biosynthesis in S. natalensis. The engineered S. chattanoogensis D1, generated by inserting an additional copy of scnRII into the chromosome of strain L10, increased its natamycin production by 3.3 fold in YSG medium and 4.6 fold in YEME medium without sucrose.

Neurotrophic Artemin Promotes Motility and Invasiveness of MIA PaCa-2 Pancreatic Cancer Cells

Meng, Ling-Xin,Chi, Yu-Hua,Wang, Xiang-Xu,Ding, Zhao-Jun,Fei, Li-Cong,Zhang, Hong,Mou, Ling,Cui, Wen,Xue, Ying-Jie Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.5

Objective: To analyze the capacity of neurotrophic artemin to promote the motility and invasiveness of MIA PaCa-2 pancreatic cancer cells. Methods: MIA PaCa-2 was cultured in vitro and studied using transwell chambers for motility and invasiveness on treatment with different concentrations of aArtemin or its receptor $GFR{\alpha}3$ were also determined. Expression of matrix metalloproteinase-2 (MMP-2) and epithelial cadherin (E-cadherin) was quantified using RT-PCR and Western blotting. Results: MIA PaCa-2 pancreatic cancer cell motility and invasiveness was significantly increased with artemin and its receptor $GFR{\alpha}3$ with dose dependence (P<0.01). MMP-2 production was also significantly increased (t = 6.35, t = 7.32), while E-cadherin was significantly lowered (t = 4.27, t = 5.61) (P <0.01). Conclusion: Artemin and its receptor $GFR{\alpha}3$ can promote pancreatic cancer cell motility and invasiveness and contribute to aggressive behavior. The mechanism may be related to increased expression of MMP-2 molecule and down-regulation of E-cadherin expression.

Theoretical Studies on Electronic Structure and Absorption Spectrum of Prototypical Technetium-Diphosphonate Complex ^99mTc-MDP

Qiu, Ling,Lin, Jian-Guo,Gong, Xue-Dong,Ju, Xue-Hai,Luo, Shi-Neng Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.7

Density functional theory (DFT) and time-dependent density functional theory (TDDFT) calculations, employing the B3LYP method and the LANL2DZ, 6-31G$^*$(LANL2DZ for Tc), 6-31G$^*$(cc-pVDZ-pp for Tc) and DGDZVP basis sets, have been performed to investigate the electronic structures and absorption spectra of the technetium-99m-labeled methylenediphosphonate ($^{99m}Tc$-MDP) complex of the simplest diphosphonate ligand. The bonding situations and natural bond orbital compositions were studied by the Mulliken population analysis (MPA) and natural bond orbital (NBO) analysis. The results indicate that the ${\sigma}$ and ${\pi}$ contributions to the Tc-O bonds are strongly polarized towards the oxygen atoms and the ionic contribution to the Tc-O bonding is larger than the covalent contribution. The electronic transitions investigated by TDDFT calculations and molecular orbital analyses show that the origin of all absorption bands is ascribed to the ligand-to-metal charge transfer (LMCT) character. The solvent effect on the electronic structures and absorption spectra has also been studied by performing DFT and TDDFT calculations at the B3LYP/6-31G$^*$(cc-pVDZ-pp for Tc) level with the integral equation formalism polarized continuum model (IEFPCM) in different media. It is found that the absorption spectra display blue shift in different extents with the increase of solvent polarity.

Traditional Chinese medicine for COVID-19 pandemic and emerging challenges: An online cross-sectional survey in China

Chun-Li Lu,Ruo-Xiang Zheng,Xue Xue,Xiao-Wen Zhang,Xue-Han Liu,Xin-Yan Jin,Feng-Lan Pu,Hui-Di Lan,Min Fang,Ling-Yao Kong,Merlin Willcox,Bertrand Graz,Joelle Houriet,Xiao-Yang Hu,Jian-ping Liu 한국한의학연구원 2021 Integrative Medicine Research Vol.10 No.-

Background We aimed to investigate use of infection control behaviours, preventative and therapeutic interventions, and outcomes among respondents to an online survey during the COVID-19 pandemic in China. Methods The survey was designed by an international team, translated and adapted to simplified Chinese, including 132 kinds of traditional Chinese medicine (TCM) preparation recommended by guidelines. It was distributed and collected from February to May 2021, with data analysed by WPS spreadsheet and wjx.cn. Descriptive statistics were used to describe demographics and clinical characteristics, diagnosis, treatments, preventative behaviours and interventions, and their associated outcomes. Results The survey was accessed 503 times with 341 (67.8%) completions covering 23 provinces and four municipalities in China. Most (282/341, 82.7%) respondents reported no symptoms during the pandemic and the majority (290/341, 85.0%) reported having a SARS-CoV-2 PCR test at some point. Forty-five (13.2%) reported having a respiratory infection, among which 19 (42.2%) took one or more categories of modern medicine, e.g. painkillers, antibiotics; 16 (35.6%) used TCM interventions(s); while seven respondents combined TCM with modern medicine. All respondents reported using at least one behavioural or medical approach to prevention, with 22.3% taking TCM and 5.3% taking modern medicines. No respondents reported having a critical condition related to COVID-19. Conclusion We found evidence of widespread use of infection control behaviours, modern medicines and TCM for treatment and prevention of COVID-19 and other respiratory symptoms. Larger scale studies are warranted, including a more representative sample exploring TCM preparations recommended in clinical guidelines. Background We aimed to investigate use of infection control behaviours, preventative and therapeutic interventions, and outcomes among respondents to an online survey during the COVID-19 pandemic in China. Methods The survey was designed by an international team, translated and adapted to simplified Chinese, including 132 kinds of traditional Chinese medicine (TCM) preparation recommended by guidelines. It was distributed and collected from February to May 2021, with data analysed by WPS spreadsheet and wjx.cn. Descriptive statistics were used to describe demographics and clinical characteristics, diagnosis, treatments, preventative behaviours and interventions, and their associated outcomes. Results The survey was accessed 503 times with 341 (67.8%) completions covering 23 provinces and four municipalities in China. Most (282/341, 82.7%) respondents reported no symptoms during the pandemic and the majority (290/341, 85.0%) reported having a SARS-CoV-2 PCR test at some point. Forty-five (13.2%) reported having a respiratory infection, among which 19 (42.2%) took one or more categories of modern medicine, e.g. painkillers, antibiotics; 16 (35.6%) used TCM interventions(s); while seven respondents combined TCM with modern medicine. All respondents reported using at least one behavioural or medical approach to prevention, with 22.3% taking TCM and 5.3% taking modern medicines. No respondents reported having a critical condition related to COVID-19. Conclusion We found evidence of widespread use of infection control behaviours, modern medicines and TCM for treatment and prevention of COVID-19 and other respiratory symptoms. Larger scale studies are warranted, including a more representative sample exploring TCM preparations recommended in clinical guidelines.