Search

By the methods of chamber-based and eddy covariance measurements, the CO2 exchange of dominant tree species Pometia tomentosa and Gironniera subaequalis at leaf and canopy levels in the tropical seasonal rain forest of Xishuangbanna was measured in different seasons of 2004. The results showed that for the two tree species, the maximum net photosynthesis (P(max A)) of canopy based on chamber-based measurement ranked in the order of rainy season (RS) > end of rainy season (ERS) > foggy-cool season (FS) > dry-hot season (DS), and the dark respiration rate (Rd) of leaf was RS > ERS > DS > FS. The P(max B) based on eddy covariance measurement was in the same order as that based on chamber-based measurement, while the canopy respiration rate (Re) was RS > DS > FS > ERS. The maximum net photosynthetic rate of canopy in different seasons measured by the two methods had a comparatively small difference, ranging from 0.9 to 2.0 micromol m(-2) s(-1).

Based on the measurement of carbon flux by the methods of eddy covariance and static chamber/gas chromatogram, a comparison was made between the two methods in evaluating ecosystem respiration over winter wheat (Triticum aestivum)--summer maize (Zea mays) double cropland and Kobresia humilis alpine meadow. The results showed that under the conditions of obtained data having good quality, nighttime ecosystem respiration from eddy covariance measurement was significantly agreed with that from static chamber/gas chromatogram measurement, with the correlation coefficients ranging from 0.95 to 0.98, and the daytime ecosystem respiration from these two measurements also had a good consistency though the static chamber/gas chromatogram measurement often produced higher values. The daily mean value of ecosystem respiration was significantly different between these two measurements, but the seasonal pattern was similar. For winter wheat-summer maize double cropland, the difference of mean air temperature inside and outside the chamber was 1.8 degrees C, and the daily mean value of ecosystem respiration across the whole study period was 30.3% lower in eddy covariance measurement than in static chamber/gas chromatogram measurement; while for alpine meadow, the difference of the mean air temperature was 1.9 degrees C, and the daily mean value of ecosystem respiration was 31.4% lower in eddy covariance measurement than in static chamber/gas chromatogram measurement. The variance between the daily mean values of ecosystem respiration obtained from the two measurements was higher in growing season than in dormant season.

Objective: To identify the binding site on glycophorin A (GPA) for EBA-175 to provide clue for developing short peptide vaccine and therapeutic agents against Plasmodium falciparum., Methods: With the recombinant protein of EBA-175 as the target molecule, the mimetic peptides of GPA were screened from a 12-mer random peptide library. Three rounds of biopanning were carried out, and enzyme-linked immunosorbent assay (ELISA), competitive ELISA, Dot-ELISA and Western blotting used to evaluate the binding between the phage-borne peptides and EBA-175. The insert DNA sequences of positive clones were determined and their amino acid sequences deduced., Results: Thirty clones from the third round were randomly selected, of which 27 were found positive by sandwich ELISA. Competitive ELISA proved that most of the phage-borne peptides could competitively inhibit the binding of antibody (EBA-175 Ab) with EBA-175. Analysis of DNA and amino acid sequences indicated that 24 positive phage clones contained the conservative sequence of IRR, which was highly homologous with the 114-116 amino acids of GPA., Conclusion: These phage-displayed peptides can bind with EBA-175, and the amino acid sequence IRR might play an important role in the binding between EBA-175 and GPA.

The measurement of CO2 turbulent exchange in a broadleaved Korean pine forest in Changbai Mountains by an open-path eddy covariance system showed that with near neutral atmospheric stratification, the CO2 and vertical wind components over canopy in inertial subrange followed the expected -2/3 power law, and the dominant vertical eddy scale was about 40 m. The frequency ranges of eddy contributions to CO2 fluxes were mostly within 0.01-2.0 Hz, and the eddy translated by low frequency over canopy contributed more of CO2 fluxes. The open-path eddy covariance system could satisfy the estimation of turbulent fluxes over canopy, but the CO2 fluxes between forest and atmosphere were generally underestimated at night because the increment of non turbulent processes, suggesting that the CO2 fluxes estimated under weak turbulence needed to revise correspondingly.

Objective: To explore the clinical manifestation of subhealth status in teachers and medical staff., Methods: An on-the-spot investigation was conducted in 891 personnel of a medical college using a self-designed subhealth questionnaire. The diagnostic criteria for subhealth status were formulated on the basis of literature review and expert counseling. The results were analyzed by frequency analysis and multiple-factor logistic analyses., Results: The total subhealth incidence was 57.2 %, and the clinical manifestations included many symptoms of the body, psychology and society. Multiple-factor logistic analysis revealed the most common clinical manifestations of subhealth status including ademonia, weariness, insomnia, waist and back pain, frequent sighs, eye dryness, inattention, irritability, foot and hand coldness, vulnerability to common cold etc., Conclusion: The clinical manifestations of sub-health status complex.

Objective: To prepare and characterize the monoclonal antibodies (mAbs) against erythrocyte-binding antigen 175 of Plasmodium falciparum (EBA-175)., Methods: BALB/ c mice were immunized with purified recombinant EBA-175 and mAbs against EBA-175 were prepared by means of hybridoma technique. Enzyme-linked immunosorbent assay (ELISA) and Western blotting were employed for characterization of the mAbs., Results: Six McAbs against EBA-175 antigen were obtained, 5 of which were identified as IgG1 and one as IgG2a. The titer of these aAbs was 1:12,800 to 1:25,600 in the ascites and 1:256 to 1:512 in supernatant, and ELISA demonstrated specific binding of the 4 mAbs (1F3, 2H5, 4A1 and 4H9)with Plasmodium falciparum. Three of these mAbs recognized the protein of EBA-175 as shown by Western blotting., Conclusion: Six hybridoma cell lines secreting the mAbs against EBA175 with high specificity are successfully established.

Background & Objective: Cytological examination, despite of its high specificity, has been found to have a low sensitivity in the diagnosis of malignant ascites due to the high percentage of false negative results. So it is indispensable to seek appropriate cancerous markers in ascites. The aim of this study was to determine vascular endothelial growth factor (VEGF), CD44v6 levels and matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9) activities in ascites so as to provide scientific basis for clinical diagnosis and treatment of malignant ascites., Methods: A total of 67 samples were collected, including cirrhotic ascites (36), tuberculosis ascites (8), and malignant ascites (23). VEGF and CD44v6 levels were determined using enzyme-linked immunosorbent assay (ELASA). MMP-2 and MMP-9 activities were determined by gelatin zymography., Results: VEGF and CD44v6 levels in malignant ascites were 640.74+/-264.81 ng/L and 89.22+/-38.20 microg/L, respectively, which were significantly higher than those in cirrhotic ascites (67.05+/-51.91 ng/L, 44.79+/-18.02 microg/L) and tuberculosis ascites (88.25+/-24.12 ng/L, 50.25+/-12.57 microg/L) (P< 0.01, respectively). The activities of MMP-2 and MMP-9 could not be detected in cirrhotic ascites and tuberculosis ascites but could be detected in 20 and 18 out of 23 malignant ascites respectively., Conclusion: VEGF, CD44v6 levels increase significantly and MMP-2, MMP-9 activities are obvious in cancerous ascites. The detection of VEGF, CD44v6 levels and MMP-2, MMP-9 activities are useful in differential diagnosis of benign and malignant ascites.

Objective. To investigate the effect of eccentric strengthening (EC) exercise on muscular structure, plasma CK and biomechanical behavior under different mechanical loadings and to study the mechanical factors involved in sports muscle injury. Method. We developed an apparatus to do eccentric strength training with male SD rats under different mechanical loadings and to measure the biomechanical behavior. Result. No significant difference (P>0.05) of muscular structure, plasma CK and biomechanical behavior were found between high and low force groups. Conclusion. Skeletal muscle injury after cyclic EC with different mechanical loadings suggested that muscle damage is not simply a function of peak muscle force.