ISSN 0253-2778

CN 34-1054/N

2016 Vol. 46, No. 10

Display Method:
Labelling cell organelles with dual orthogonal click reaction pairs
LUO Yufeng, LIANG Gaolin
2016, 46(10): 797-802. doi: 10.3969/j.issn.0253-2778.2016.10.001
While single click reactions for cell imaging are widely applied, employing multiple orthogonal click reactions tracking multiple complex intracellular systems within one cell remains challenging. Our research combined two click reactions with different reaction mechanisms: tetrazine- alkene [4+2] inverse electron demand Diels-Alder cycloaddition, and CBT-Cys condensation reaction. Orthogonality between these two reactions was studied and the two reactions were applied for simultaneous labeling mitochondria and outer cell membrane of HepG2 cells. The results indicate that it is possible to use two (or n) orthogonal click reactions to track multiple organelles within one cell.
Codopants (Cu, Li, Cr) mediating distribution of magnetic Co ions in Co-doped ZnO
CHEN Lin, HU Fengchun, TAN Hao, DUAN Hengli, SUN Zhihu, YAN Wensheng
2016, 46(10): 803-808. doi: 10.3969/j.issn.0253-2778.2016.10.002
X-ray absorption fine structure (XAFS) and X-ray photoelectron spectroscopy (XPS) were combined to study the effect of (Cr, Cu, Li) codopants on the distribution of magnetic Co atoms in Co-doped ZnO thin films. For the single-doping of Co in ZnO, there are two occupation sites of Co in ZnO: the substitutional sites for Zn and metallic Co clusters. After Cr doping, the metallic Co clusters vanish and all the Co atoms occupy the substitutional sites. On the contrary, Cu(Li)-codoping further increases the content of metallic Co clusters. In-depth analysis suggests that the distinct roles of Cr and Cu(Li) codopants for mediating the distribution of Co atoms in ZnO are intimately related to the occupation sites of codopants.
Ag(Ⅰ) catalyzed intramolecular hydroamination-Michael addition cascade reaction
WU Peiyu, HAN Zhiyong
2016, 46(10): 809-813. doi: 10.3969/j.issn.0253-2778.2016.10.003
Starting from amino alkynes derived from glycine esters, silver(Ⅰ) catalyst was employed for a tandem intramolecular hydroamination/Michael addition process under mild conditions. This reaction provides an efficient approach to substituted 3,4-dihydro-2H-pyrroles
Analysis of essential oil of Dendranthema morifolium cv. Chuju by GC×GC-TOF/MS with supercritical CO2 extraction
HUANG Guifeng, XU Zhiqiang, GE Shaolin, HUANG Lan, TIAN Zhenfeng, ZOU Peng, YANG Jun
2016, 46(10): 814-820. doi: 10.3969/j.issn.0253-2778.2016.10.004
The chemical compounds of essential oil from the flowers of Dendranthema morifolium cv. Chuju were studied by comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-TOF/MS) combined with supercritical carbon dioxide extraction (SFE). The effects of SFE different parameters including extraction pressure, co-solvent content, extraction time, extraction temperature and CO2 flow rate on the essential oil yield was investigated using orthogonal array design. The results indicate that the optimal extraction conditions are as follow: pressure 35 MPa, co-solvent content 16%, temperature 55 ℃, extraction time 3 h and CO2 flow rate 50 kg/h. Under the optimal extraction conditions, the essential oil yield is 640%. By searching TOF/MS spectral library and comparing the GC×GC retention indices with database values, 92 compounds are identified. The major constituents in the essential oil are terpenoids which make up 6674% of the identified volatile compounds. In addition, three important floral aroma components, 3,4-didehydro-β-ionone, β-Ionon-5,6-epoxide, 3-Hydroxy-5,6-epoxy-β-ionone are rudimentarily found in Dendranthema morifolium.
Microfluidic paper-based analytical device for colorimetric screening prior to mass spectrometry analysis
LIU Mengmeng, HUANG Guangming
2016, 46(10): 821-831. doi: 10.3969/j.issn.0253-2778.2016.10.005
In order to improve the efficiency of mass spectrometry(MS) instrument, a microfluidic paper-based analytical device (μPAD) was designed for sample loading and pre-screening. Samples loaded on μPAD can be split into two separated detection zones. Colorimetric detection with the naked eye can be viewed as fast screening. Samples with significantly lower or higher colorimetric response than threshold may be ignored. For suspicious samples, final detection with much higher sensitivity would be carried out with MS. Using the present method, quantifications of Ang II in raw serum with both colorimetry and MS were achieved. For colorimetric detection, the resulting linear range of 200~1 000 μmol/L was established, and the visual detection limit was in the range of 150~200 μmol/L. For MS detection, the linear dynamic range for Ang II was 5~500 μmol/L. The limit of detection (LOD) was measured to be 19 μmol/L using bradykinin as the internal standard. The result indicates that this protocol would enable easy sample transportation, rapid screening and sensitive MS measurement with a single μPAD device.
Expression of an Azurin mutant and its interaction with a prodrug of cisplatin
LIU Xiaoxuan, WANG Zhen, LIANG Gaolin, ZHAO Linhong
2016, 46(10): 832-837. doi: 10.3969/j.issn.0253-2778.2016.10.006
Azurin is a copper protein and possesses antitumor activity. The H117G mutant of Azurin (Az-H117G) was prepared, which is capable to bind exogenous imidazole or histidine. The interaction of Az-H117G with imidazole-based derivatives was investigated using UV-vis spectroscopy. Results show that the protein mutant can bind imidazole, histidine and Pt-His complex, a Pt(IV) prodrug of cisplatin. Based on this information, the protein/drug conjugate was prepared and the anti-proliferation of tumor cells was studied. The result indicates that this protein/drug conjugate might be potentially applicable to antitumor drug design.
Analysis of porcelain unearthed from Liu Zi Canal Ruins — A case study of a white glazed cup with carved lotus petals and a greenish white glazed bowl
HU Jun, CHEN Chao, QIN Ying, GONG Decai
2016, 46(10): 838-844. doi: 10.3969/j.issn.0253-2778.2016.10.007
Two porcelains which waited for repairing were studied by several instruments, such as polarized light microscopy, X-ray fluorescence spectrometry and dilatometer. The results show that the sample (inside the white glazed cup with carved lotus petals) contains a lot of angular quartz grains and dark iron minerals, and the main filler in the carved pattern is iron minerals. While in another sample (inside the body of the greenish white glazed bowl) more grinded clinker particles are found. It is concluded that the vessels may have been made in Xiao kiln and Jingdezhen kiln. The pollutants on the surface of the porcelains are soil rust and iron rust.
Effects of PCM on thermal control performance of a thermal control system subjected to periodic ambient conditions
YE Hong, WANG Zijun, WANG Liwei, WEI Xuezhong
2016, 46(10): 845-852. doi: 10.3969/j.issn.0253-2778.2016.10.008
Thermal control systems operating under periodic outdoor ambient conditions have numerous important applications in the industrial fields, and reducing system energy consumption and enhancing temperature control effects are key to their performance improvement. Therefore, the influences of phase change material (PCM) in the envelope of a thermal control system on thermal control effects were studied by means of experiment and simulation. The results of the typical meteorological day show that, compared with polystyrene, PCM can significantly reduce system energy consumption (by 754%), surface temperature fluctuation (by 761%) and axial temperature difference (by 569%) of the object in Guangzhou. In Nanjing and Turpan, the surface temperature fluctuation can be reduced by 413% and 306% respectively, no improvement is observed in system energy consumption and axial temperature difference. The results of the typical meteorological year indicate that PCM also exhibits the advantages of thermal control in Guangzhou, but thermal control effects are strongly dependent on the temperature control setpoint, phase change range and the fluctuation of the ambient temperature. When the phase change range of the selected PCM covers the setpoint and the fluctuation range of the ambient temperature, PCM can maximize thermal control effects.
Numerical study on the near wake of a circular disk in shear flows
QIAN Wanyi, YANG Jianzhi, GU Hailin, YAO Mengyun, ZHAO Pu, LIU Minghou
2016, 46(10): 853-859. doi: 10.3969/j.issn.0253-2778.2016.10.009
Numerical investigations on the near wake of a circular disk in a shear flow at low Reynolds numbers were performed using DNS, with focus on the effect of shear rate on the wake structures. The Reynolds numbers considered were 140, 160 and 300, and the non-dimensional shear rate k of inlet flow was varied from 0 to 01. At Re=140 and 160, the wake changes to the unsteady state with planar-symmetry, indicating that the critical Re of this mode decreases in the uniform shear flow. The head of the hairpin vortex loop is always much larger on the high-velocity side within the shear flow, and at Re=160 the planar symmetry gradually moves to the xoy plane with the increase of the shear rate k. At Re=300, no obvious changes of the wake structures are observed, and the wake is still in the weakly-chaotic state. It is also found that, for low values of k (k<01), the non-dimensional vortex shedding frequency of the shear flow is nearly the same as that of uniform flow.
Studies on lignin depolymerization by CeO2 and La2O3 in alkaline systems
DU Zhijie, LI Wenzhi, MA Qiaozhi, WANG Jingdong
2016, 46(10): 860-866. doi: 10.3969/j.issn.0253-2778.2016.10.010
Insomnia discriminant analysis based on real-world clinical data
ZHU Wei, YAN Shixing, ZHANG Lei, LI Guozheng
2016, 46(10): 867-873. doi: 10.3969/j.issn.0253-2778.2016.10.011
A new data preprocessing method based on the real-world medical database was proposed, which can change unstructured data into structured data. Supervised algorithms and semi-supervised algorithms were utilized to verify the effectiveness of the clinical features which were obtained through our data preprocessing method. From the experimental results on the real world dataset, it is found that both supervised classification and semi-supervised algorithms can get a better result based on the clinical symptom features trained from our data preprocessing method. And it is found that the label propagation algorithm not only achieves a great stability on the real Chinese medicine database when compared with classical classification algorithm, but also obtains good results when the ratio is low.
Sentiment analysis based on grid clustering
MIAO Yuqing, GAO Han, LIU Tonglai, WEN Yimin
2016, 46(10): 874-882. doi: 10.3969/j.issn.0253-2778.2016.10.012
To expand a lexicon, the methods of point mutual information (PMI), setting the threshold parameter, etc. were used to automatically identify, extract and classification the words which are not included in the HowNet but have a certain emotional tendency. On that basis, a feature vector model based on commodity comments was established, and the SCG (sentiment classification based on grid clustering) algorithm was presented. Next, the grid-based clustering algorithm was used to build up a classification model. The amount of calculation decreased after the dynamic attenuation factors were introduced and sparse grids were periodically removed in the grid-based clustering process. Experimental results indicate that the classification accuracy and field adaptability of SCG is higher, compared with other algorithms such as Naive Bayes, SMO (sequential minimal optimization).