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Hui Ding

Publications and source records attributed to Hui Ding.

28 records · Page 2Linked to original sources
PubMed2005

[Algorithm for recognizing the markers in human motion detection].

An algorithm for recognizing the markers in human motion detection is proposed in this paper. It includes three parts as follows: (1) an improved template matching method is used to acuminate the peak of the matching result. (2) The weighted average of the cross correlation between target image and template is given in order to make the resolution increase to sub-pixel level. (3) Forecasting the motion of marker and overcoming the hiding of marker are realized basing on the continuity of human motion. The result of experiments shows that the algorithm can recognize the positions of the markers at a relatively higher accuracy and speed. A gait analysis system based on this algorithm has come into use.

Algorithms↗
PubMed2005

Metal bioaccumulation in plant leaves from an industrious area and the botanical garden in Beijing.

The concentrations of Fe, Mn, Al, Zn, Pb, Ni, Cr, and As were measured in soils and leaves from 21 plant species growing on hills near the Beijing Steel Factory (BSF) and 17 plant species in the Beijing Botanical Garden (BBG). The results showed that soils from BSF were Zn contaminated according to the threshold of natural background of China. There was a metal contamination of the soils by Ni, and Cr in BSF comparing with those in BBG. The comparison between concentrations of metals in leaves from both sites indicated that, in general, accumulation of metals in the leaves of the same species was significantly different between the two sites. Even within the same locality each species accumulation of metals was significantly variable. The study aimed to screen landscape plants for the capacity to clean-up toxic metals in soils, and developed an overall metal accumulation index (MAI) for leaves and then categorized the MAI that can be applied broadly in the selection of species in polluted areas. To do this, the spectrum of MAI values were divided into four classes: strongly accumulated (SA or grade I), moderately accumulated (MA or grade II), intermediately accumulated (IA or grade III), and weakly accumulated (WA or grade IV). The results showed that elemental association between Fe, Al, Ni, and As was generally highly correlated with each other in the sampling sites. This may suggest their common biochemical characteristics. Generally, those species containing strong and moderate accumulation in both sites are considered including Vitex negundo, Broussonetia papyrifera, Ulmus pumila, and Rubia cordifolia. At BSF and other industrial sites with a similar ecosystem, strong and moderate accumulation species include Sophora japonica, Ampelopsis aconitifolia var. glabra, Platycladus orientalis, Wikstroemia chamaedaphne, Cleistogenes squarrosa, Grewia biloba, and in BBG, in addition Setaria viridis, Cotinus coggygria, Lespedeza floribunda, Rhamnus parvifolia, Lespedeza tomentosa.

China↗
PubMed2005

Persistent organochlorine residues in sediments of Haihe River and Dagu Drainage River in Tianjin, China.

Persistent organochlorine compounds were analyzed by means of GC-ECD in surface sediment samples from two selected rivers in Tianjin, Haihe River and Dagu Drainage River. A total of 16 surface sediment sites were selected along the both rivers. The frequency of detection of T-HCH and T-DDT in sediment samples both was up to 100%, which illustrated that the contamination of HCH and DDT was widespread in Haihe and Dagu Drainage Rivers. Results indicated that the concentrations of various pesticides in sediments from Haihe River were in the range of 3.30-75.96 ng/g dw for T-HCH and 1.57-211.57 ng/g dw for T-DDT. Compared with Haihe River, Dagu Drainage River was contaminated by HCHs and DDTs along the all locations and the values of T-HCH and T-DDT residues in sediments ranged from 2.30 to 124.61 ng/g dw and from 11.28 to 237.30 ng/g dw, respectively. The possible pollution sources were analyzed through monitoring results of organochlorine pesticides(OCPs) residues in sediments from the two rivers. The investigation also indicated that HCH was still used as pesticide in Tianjin partial area.

China↗
PubMed2004

Trifluoroacetyl-activated nitrogen-nitrogen bond cleavage of hydrazines by samarium(II) iodide.

[reaction: see text] Trifluoroacetyl derivatives of hydrazines undergo clean and efficient reductive cleavage of the N-N bond with SmI(2) in the presence of MeOH. After N-trifluoroacetylation, acyl-, aryl-, and alkyl-substituted hydrazines are reductively cleaved by this method to afford trifluoroacetamides in yields ranging from 70 to 96%. These conditions accommodate alkene functionality, avoid racemization, and furnish chiral amines bearing a readily removable TFA protecting group.

Hydrazines↗
PubMed2004

[Epidemiological study on rotavirus-borne diarrhea in infants and children in different areas].

OBJECTIVE: To analyze and compare the epidemiological features of rotavirus diarrhea among infants in the different areas so as to provide data for rotavirus vaccine research. METHODS: From Sep. 2001 through Sep. 2003, sentinel sites were set up in Suzhou Children's Hospital and Maanshan Hospital. Fecal samples from children (< 5 years) with acute diarrheal were collected and enzyme linked immunosorbent assay was used to detect rotavirus antigen. Reverse transcription-polymerase chain reaction was used to determine the G serotypes and P genotypes of rotavirus strains. The features of strains in the two places and other areas of China were analyzed and compared. RESULTS: (1) Rotavirus infection appeared in autumn and winter, but the peaks varied. In Suzhou the peaks were from December to next February in 2001, and November to next January in 2002. But in Maanshan, it was November to next January for both two years. (2) Rate of rotavirus infection in Suzhou was much higher than that in Maanshan, infective rates of Inpatient Department and Outpatient Department are 47.28%, 28.39% and 30.38%, 14.77% respectively in the two hospitals. (3) Rates of infection in two hospitals showed age difference but the highest group was in 6 - 35 month-olds. No gender difference was found. (4) Secular distribution of G-typing and P-typing of rotavirus strain was different in Suzhou and Maanshan. G3 was mainly found in Suzhou and G1 in Maanshan. From 2002-2003 on, G3 became dominant in Maanshan. CONCLUSION: Rotavirus caused diarrhea among infant and children were different in terms of areas, period and types, suggesting that the introduction of rotavirus vaccine should be adjusted according to different strains with specific types and optimal timeline.

Child, Preschool↗
PubMed2003

[Measurement and statistical analysis of the vertical force in normal young people's gait].

OBJECTIVE: To find a method for evaluating the relationship between mechanical data and gait efficiently. METHOD: Gait mechanical data of 27 young men (20-22 years) without history of the kinetic diseases were collected using a force-measuring system. The data were transformed into characteristic two-peak curves in vertical direction (z-axis). Seven characteristic parameters were distilled. The coefficient of variation (CV) and the absolute symmetry index (ASI) of the parameters between left foot and right foot were analyzed. RESULT: It was found that CV of the first temporal parameter of gait (T(Z1)) is equal to 14.49%, which corresponds to larger dispersion. The values of ASI are all lower than 12.5%, which means the symmetry between left and right feet meets general requirement. But the P value (result of t-test) of F(Z2) is 0.0368 (lower than 0.05), which means that there is obvious differentia between F(Z2) of left and right feet, while no such differentiae were found for the other six characteristic parameters. t-test was also used to analyze the differentia between the gait of male and female. It is still found that p value of F(Z2) is lower than 0.01, which corresponds to a great differentia on F(Z2) between male and female. CONCLUSION: Some significant conclusions of the repetition, dispersion, symmetry and differentia of gait data have been obtained by the analysis.

Adult↗
PubMed2002

[A gait analysis system based on digital video and digital image processing].

OBJECTIVE: To provide a gait analysis system. METHOD: The system is composed of general video devices and personal computer hardware. The techniques of digital video and digital image processing such as template matching, sub-pixel and motion estimate etc were employed to identify and trace the markers. RESULT: A gait result of a cerebral palsy object, which consists of bar-figure, data, and video was provided. CONCLUSION: The gait analysis system based on digital video and digital image processing is easy to use, and can provide visual result, which is easy to understand.

Cerebral Palsy↗
PubMed1999

Self-Assembling Calix[4]arene [2]Catenanes. Preorganization, Conformation, Selectivity, and Efficiency.

A novel class of preorganized U-shape calix[4]arene clefts, dicationic salts 3a,c,e.2Cl, 3b.2PF(6)(), and 3f.2Br, consisting of one cone calix[4]arene and two bipyridine residues being linked by an aliphatic chain, have been designed and synthesized as precursors for self-assembly of calix[4]arene [2]catenanes by utilizing pi-stacking interactions between the hydroquinone and bipyridinium units. Conformationally flexible 6.2PF(6)() and cone 10.2Cl, whose conformation is fixed by two propyloxy groups on the lower rim, were also prepared in order to explore the effects of conformation and hydrogen bonding of the calix[4]arene moiety on self-assembly. For all reactions, bis-p-phenylene-34-crown ether-10 (11) was employed as the donor component. Alternate cone [2]catenane 13.4Cl is obtained in 8% yield from reaction of ethylene-incorporating 3a.2Cl and 1,4-bis(bromomethyl)benzene (12a). Three cone and one conformationally flexible [2]catenanes were obtained in moderate to good yields from reactions of propylene-incorporating 3b.PF(6)() and 3c.2Cl with 12a, 1,3-bis(bromomethyl)benzene (12b) or 4,4'-(bromomethyl)biphenyl (12c). Both cone and partial cone [2]catenanes were generated in moderate yields from butylene-incorporating 3c.2Cl with four tert-butyl groups on the calix[4]arene moiety and with 12a. In contrast, only cone [2]catenane was obtained from similar tert-butyl-free cleft 3d.2Cl. Cone and conformationally flexible [2]catenanes were obtained in moderate yields, respectively, from the reactions of 3d.2Cl and 3e.2Cl with 12c. No catenanes were isolated from reaction of phenylene-incorporating 3f.2Br or 6.2Cl, whereas reaction of 10.2Cl afforded cone [2]catenane in low yield. It was demonstrated that hydrogen bonding, which may be destroyed after catenation, within the calix[4]arene moiety is crucial for efficient self-assembly of the [2]catenanes. The dynamic (1)H NMR and absorption spectra and luminescent properties of the [2]catenanes were investigated, which reveal that incorporation of calix[4]arene into the tetracationic cyclophane reduces pi-stacking interactions between the donor and acceptor units and catenation has substantial influence on conformational distributions of the calix[4]arene moiety. The results demonstrate the versatility of calix[4]arene derivatives as building blocks in the construction of supramolecular structures.

Journal Article↗
PubMedDate not supplied

Identification of CD21-binding peptides with phage display and investigation of binding properties of HPMA copolymer-peptide conjugates.

Cancer targeting with peptides has become promising with the emergence of combinatorial peptide techniques such as phage display. Using phage display under stringent screening conditions, we selected five distinct peptides that specifically recognized the CD21 receptor, a cell surface marker of malignant B cell lymphoma. Two highly hydrophobic sequences were excluded (RLAYWCFSGLFLLVC and PVAAVSFVPYLVKTY). The binding affinity toward CD21 of the other three selected peptides (RMWPSSTVNLSAGRR, PNLDFSPTCSFRFGC, and GRVPSMFGGHFFFSR) was analyzed with fluorescence quenching. Their dissociation constants were determined to be within the micromolar range. On the basis of the results of phage ELISA, competitive phage ELISA, and fluorescence quenching, the binding sites of the three selected peptides were found to reside within the first four short consensus repeats of CD21 (SCR1-4). The peptide RMWPSSTVNLSAGRR (P1) was bound to the N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer, a potential drug carrier for chemotherapeutic agents, and the surface binding properties of HPMA copolymer-P1 conjugates were investigated. Specific interactions were observed between HPMA copolymer-P1 conjugates and surface-bound receptor. Binding of HPMA copolymer-P1 conjugates was directly related to the amount of surface (MaxiSorp plate) bound receptor, and the binding of the conjugates could be inhibited by the application of a 3-4 orders-of-magnitude excess of free peptide over the peptide concentration in conjugates. The enhanced binding of polymer-bound peptide was ascribed to multivalent interactions between the HPMA copolymer-P1 conjugate and the surface-bound CD21 receptor.

Amino Acid Sequence↗