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Characteristics of photosynthesis in rice plants transformed with an antisense Rubisco activase gene
JIN Song-heng, JIANG De-an, LI Xue-qin, SUN Jun-wei
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2004, 5(8): 897-899.
https://doi.org/10.1631/jzus.2004.0897
Transgenic rice plants with an antisense gene inserted via Agrobacterium tumefaciens were used to explore the impact of the reduction of Rubisco activase (RCA) on Rubisco and photosynthesis. In this study, transformants containing 15% to 35% wild type Rubisco activase were selected, which could survive in ambient CO2 concentration but grew slowly compared with wild type controls. Gas exchange measurements indicated that the rate of photosynthesis decreased significantly, while stomatal conductance and transpiration rate did not change; and that the intercellular CO2 concentration even increased. Rubisco determination showed that these plants had approximately twice as much Rubisco as the wild types, although they showed 70% lower rate of photosynthesis, which was likely an acclimation response to the reduction in Rubsico activase and/or the reduction in carbamylation.
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Charge dynamic characteristics in corona-charged polytetrafluoroethylene film electrets
CHEN Gang-jin, XIAO Hui-ming, ZHU Chun-feng
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2004, 5(8): 923-927.
https://doi.org/10.1631/jzus.2004.0923
In this work, the charge dynamics characteristics of injection, transport and decay in porous and non-porous polytetrafluoroethylene (PTFE) film electrets were investigated by means of corona charging, isothermal and thermal stimulating surface-potential decay measurements. The results showed that the initial surface potential, whether positively or negatively charging, is much higher in non-porous PTFE than in porous PTFE. For porous film the value of initial surface potentials increases with increase of film thickness. Higher charging temperature can remarkably improve charge stability. The charge dynamics are correlated to materials microstructure according to their scanning electron micrographs. For non-porous PTFE films, polarizability change of C-F bonds is the main origin of electret charges; but for porous PTFE film a large number of bulk and interface type traps are expected because of the greater area of interface and higher crystallinity.
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Water-dispersed bone morphogenetic protein nanospheres prepared by co-precipitation method
JIANG Bing-bing, GAO Chang-you, HU Ling, SHEN Jia-cong
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2004, 5(8): 936-940.
https://doi.org/10.1631/jzus.2004.0936
A modified complex coacervation-co-precipitation method was used to prepare bone morphogenetic protein (BMP)-loaded nanospheres. Three natural polymers were used as packing materials to obtain nanoscale delivery device for BMP, in the presence of phosphatidylcholine functioning as stabilizer. Positively charged polysaccharide, N,N-diethylaminoethyl dextran (DEAE-dextran) tended to form stable, uniform and smaller size particles carrying BMP. Negatively charged bovine serum al-bumin (BSA) induced precipitation of the produced BMP particles due to its weak interaction with BMP molecules, although it produced nanosized BMP spheres. While collagen, a weakly positively charged protein shaped larger particles due to the strong interaction among themselves. A mechanism of co-precipitation process was also deduced to depict the formation of stable nanospheres.
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Study of CNG/diesel dual fuel engine\'s emissions by means of RBF neural network
LIU Zhen-tao, FEI Shao-mei
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2004, 5(8): 960-965.
https://doi.org/10.1631/jzus.2004.0960
Great efforts have been made to resolve the serious environmental pollution and inevitable declining of energy resources. A review of Chinese fuel reserves and engine technology showed that compressed natural gas (CNG)/diesel dual fuel engine (DFE) was one of the best solutions for the above problems at present. In order to study and improve the emission per-formance of CNG/diesel DFE, an emission model for DFE based on radial basis function (RBF) neural network was developed which was a black-box input-output training data model not require priori knowledge. The RBF centers and the connected weights could be selected automatically according to the distribution of the training data in input-output space and the given approximating error. Studies showed that the predicted results accorded well with the experimental data over a large range of operating conditions from low load to high load. The developed emissions model based on the RBF neural network could be used to successfully predict and optimize the emissions performance of DFE. And the effect of the DFE main performance parameters, such as rotation speed, load, pilot quantity and injection timing, were also predicted by means of this model. In resumé, an emission prediction model for CNG/diesel DFE based on RBF neural network was built for analyzing the effect of the main performance parameters on the CO, NOx emissions of DFE. The predicted results agreed quite well with the traditional emissions model, which indicated that the model had certain application value, although it still has some limitations, because of its high dependence on the quantity of the experimental sample data.
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Neogene coupling between Kuqa Basin and Southern Tien Shan Orogen, Northwestern China
HE Guang-yu, CHEN Han-lin
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2004, 5(8): 970-975.
https://doi.org/10.1631/jzus.2004.0970
Based on the sedimentary and subsiding features of Kuqa foreland basin, this paper presents the following characteristics of Neogene coupling relationship between Kuqa Basin and Southern Tien Shan Orogen, Northwestern China: (1) The Southern Tien Shan Orogen underwent Neogene uplifting of 4 km in height and the Kuqa Basin underwent Neogene subsidence of 4-6 km in depth accordingly beginning in 25 Ma; (2) The Southern Tien Shan Orogen moved continuously toward the Kuqa Basin, with largest structural shortening rate of greater than 53.7%, and the north boundary of the Kuqa Basin retreated continuously southward accordingly since the Miocene; (3) There are two subsidence centers with high subsiding rates and large subsiding extent, located in the eastern and western Kuqa Basin respectively, with the subsiding maximizing in the deposition period of Kuqa Formation.
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Hydrocarbon charging histories of the Ordovician reservoir in the Tahe oil field, Tarim Basin, China
LI Chun-quan, CHEN Hong-han, LI Si-tian, ZHANG Xi-ming, CHEN Han-lin
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2004, 5(8): 976-978.
https://doi.org/10.1631/jzus.2004.0976
The Ordovician reservoir of the Tahe oil field went through many tectonic reconstructions, and was characterized by multiple hydrocarbon chargings. The aim of this study was to unravel the complex charging histories. Systematic analysis of fluid inclusions was employed to complete the investigation. Fluorescence observation of oil inclusions under UV light, and microthermometry of both oil and aqueous inclusions in 105 core samples taken from the Ordovician reservoir indicated that the Ordovician reservoir underwent four oil chargings and a gas charging. The hydrocarbon chargings occurred at the late Hercynian, the Indo-Sinian and Yanshan, the early Himalaya, the middle Himalaya, and the late Himalaya, respectively. The critical hydrocarbon charging time was at the late Hercynian.
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Petrology, geochemistry and geodynamics of basic granulite from the Altay area, North Xinjiang, China
LI Zi-long, CHEN Han-lin, YANG Shu-feng, DONG Chuan-wan, XIAO Wen-jiao
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2004, 5(8): 979-984.
https://doi.org/10.1631/jzus.2004.0979
The basic granulite of the Altay orogenic belt occurs as tectonic lens in the Devonian medium- to lower-grade metamorphic beds through fault contact. The Altay granulite (AG) is an amphibole plagioclase two-pyroxene granulite and is mainly composed of two pyroxenes, plagioclase, amphibole and biotite. Its melano-minerals are rich in Mg/(Mg+Fe2+), and its amphibole and biotite are rich in TiO2. The AG is rich in Mg/(Mg+Fe2+), Al2O3 and depletion of U, Th and Rb contents. The AG has moderate ∑REE and LREE-enriched with weak positive Eu anomaly. The AG shows island-arc pattern with negative Nb, P and Ti anomalies, reflecting that formation of the AG may be associated with subduction. Geochemical and mineral composition data reflect that the protolith of the AG is calc-alkaline basalt and formed by granulite facies metamorphism having peak P-T conditions of 750 °C-780 °C and 0.6-0.7 Gpa. The AG formation underwent two stages was suggested. In the early stage of oceanic crustal subduction, calc-alkaline basalt with island-arc environment underwent granulite facies metamorphism to form the AG in deep crust, and in the late stage, the AG was thrust into the upper crust.
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Corneal relaxing incision combined with phacoemulsification and IOL implantation
SHEN Ye, TONG Jian-ping, LI Yu-min
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2004, 5(8): 985-988.
https://doi.org/10.1631/jzus.2004.0985
Objective: To analyze the effectiveness and safety of corneal relaxing incisions (CRI) in correcting keratometric astigmatism during cataract surgery. Methods: A prospective study of two groups: control group and treatment group. A treatment group included 25 eyes of 25 patients who had combined clear corneal phacoemulsification, IOL implantation and CRI. A control group included 25 eyes of 25 patients who had clear corneal phacoemulsification and IOL implantation. Postoperative keratometric astigmatism was measured at 1 week, 1 month, 3 months and 6 months. Results: CRI significantly decreased keratometric astigmatism in patients with preexisting astigmatism compared with astigmatic changes in the control group. In eyes with CRI, the mean keratometric astigmatism was 0.29±0.17 D (range 0 to 0.5 D) at 1 week, 0.41±0.21 D (range 0 to 0.82 D) at 1 month, respectively reduced by 2.42 D and 2.30 D at 1 week and 1 month postoperatively (P=0.000, P=0.000), and postoperative astigmatism was stable until 6 months follow-up. The keratometric astigmatism of all patients decreased to less than 1.00 D postoperatively. Conclusions: CRI is a practical, simple, safe and effective method to reduce preexisting astigmatism during cataract surgery. A modified nomogram is proposed. The long-term effect of CRI should be investigated.
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Investigation on apoptosis of neuronal cells induced by Amyloid beta-Protein
LUO Ben-yan, XU Zeng-bin, CHEN Zhi, CHEN Feng, TANG Min
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2004, 5(8): 989-994.
https://doi.org/10.1631/jzus.2004.0989
Objective: To construct a PC12 cell strain with neuronal differentiation, and observe the apoptosis and proliferation activity effects induced these cells by Amyloid beta-Protein (Aβ-43). Methods: 1) PC12 cells in logarithmic growth phase were subcultured for 24 h. After the culture fluid was changed, the cells were treated with Rat-β-NGF and cultured for 9 days. 2) Neuronal differentiation of PC12 cells in logarithmic growth phase were divided into four groups: control group (0), experimental group (1), experimental group (2) and experimental group (3). The concentrations of Aβ in the four groups were 0 μmol/L, 1.25 μmol/L, 2.5 μmol/L and 5 μmol/L, respectively. The cells were harvested at 24, 48 and 72 h later and stained with AnnexinV-FITC/PI after centrifugation and washing. Then flow cytometry was conducted to examine the apoptosis percentage. 3) NGF-induced PC12 cells were selected and Aβ with different concentrations was added. The final concentrations of Aβ were 0 μmol/L, 1.25 μmol/L, 2.5 μmol/L and 5 μmol/L, respectively. After the cells were incubated in an atmosphere of 5% CO2 at 37 °C in an incubator for 72 h, the OD values were examined. Results: 1) Neuronal differentiated PC12 cell lines were successfully established. 2) Flow cytometric examination indicated that Aβ (1.25, 2.5, and 5.0 μmol/L) could effectively induce apoptosis of neuronal-differented cells at the 24 h, 48 h and 72 h time points. 3) Aβ (0-5.00 μmol/L) had no obvious effect on proliferation or restraining of the neuronal differentiation of the PC12 cells after a 72 h interacting process. Conclusion: This investigation revealed successful neuronal differentiation of the PC12 cell strain. The induction of apoptosis of the neurocytes by various concentrations of Aβ was observed and the influence of Aβ on induced proliferation of PC12 cells by Rat-β-NGF was revealed. This study may provide basis for future research on the molecular cure of AD and interdiction of AD evolution.
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VEGFmRNA and eNOSmRNA expression in immature rabbits with bleomycin-induced pulmonary hypertension
GONG Fang-qi, LIN You-min, TANG Hong-feng, GU Wei-zhong, WANG Wei, KANG Man-li
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2004, 5(8): 995-1000.
https://doi.org/10.1631/jzus.2004.0995
Objective: To investigate the evolution of pulmonary hypertension, the pathological changes of pulmonary arteries, and the expression of VEGFmRNA and eNOSmRNA of pulmonary arterial endothelial cells in immature rabbits treated with intratracheal bleomycin (BLM). Methods: Immature rabbits were divided into control and BLM group. Two and four weeks after intratracheal normal saline or BLM injection, the systolic, diastolic and mean pulmonary artery pressure (PASP, PADP, MPAP) were measured by micro-catheter; the pathological changes and the expression of VEGFmRNA and eNOSmRNA of endothelial cells in pulmonary arteries were evaluated by HE and in situ hybridization. Results: Two and four weeks after intratracheal injection of BLM, the PASP, PADP and MPAP increased 53%, 49%, 52% in 2 weeks, and 43%, 89%, 56% in 4 weeks; the wall thickness increased and the cavity in middle and small pulmonary arteries became narrow; the Thickness Index (TI) and Area Index (AI) increased 25%, 14% in 2 weeks, and 22%, 24% in 4 weeks; the level of VEGFmRNA and eNOSmRNA expression decreased 46%, 43% in 2 weeks, and 43%, 51% in 4 weeks. There was no significant difference between 2 weeks and 4 weeks BLM groups. Conclusion: The pulmonary artery pressure was elevated, the thickness of wall increased and the cavity became narrow in middle and small pulmonary arteries, and the level of VEGFmRNA and eNOSmRNA expression in pulmonary arterial endothelial cells decreased in immature rabbits after 2 weeks and 4 weeks of intratracheal 4 U/kg BLM injection.
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Effect of lead exposure on the immune function of lymphocytes and erythrocytes in preschool children
ZHAO Zheng-yan, LI Rong, SUN Li, LI Zhi-yu, YANG Ru-lai
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2004, 5(8): 1001-1004.
https://doi.org/10.1631/jzus.2004.1001
Objective: To investigate the influence of lead exposure on the immune function of lymphocytes and erythrocytes in preschool children. Materials and methods: A group of 217 children three to six years of age from a rural area were given a thorough physical examination and the concentration of lead in blood samples taken from each subject was determined. The indices of lymphocyte immunity (CD+3CD+4, CD+3CD+8, CD+4CD+8, CD-3CD+19) and erythrocyte immunity (RBC-C3b, RBC-IC, RFER, RFIR, CD35 and its average fluorescence intensity) of 40 children with blood lead levels above 0.483 μmol/L were measured and compared with a control group. Results: The blood lead levels of the 217 children ranged from 0.11 μmol/L to 2.11 μmol/L. The CD+3CD+4and CD+4CD+8 cells were lower (P<0.01) and the CD+3CD+8 cells were higher in the lead-poisoned subjects than those in the control group (P<0.05). CD+8 and CD-3CD+19 did not show significant differences. Although the RBC-C3b rosette forming rate was lower and the RBC-IC rosette forming rate was higher in the lead-poisoned group, this difference could not be shown to be statistically significant (P>0.05). RFIR was found to be lower in the lead-poisoned group (P<0.01). Compared with the control group, the positive rate of CD35 was not found to be significantly different in a group of 25 lead-poisoned children (P>0.05), while the average fluorescence intensity was lower in the lead-poisoned group (P<0.05). Conclusion: Lead exposure can result in impaired immune function of T lymphocytes and erythrocytes in preschool children.
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Off-pump coronary artery bypass grafting versus on-pump coronary artery bypass grafting: which is better in patients with chronic obstructive pulmonary disease?
ZHU Ya-bing, XU Jian-ping, LIU Zhi-yong, YANG Dan-ning, LI Xü-dong, LI Hong-yan
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2004, 5(8): 1005-1008.
https://doi.org/10.1631/jzus.2004.1005
To evaluate the clinic outcome of off-pump coronary bypass grafting (OPCABG) of patients with coronary heart disease and chronic obstructive pulmonary disease, we collected and analyzed 1998-2002 data on 28 patients with these two diseases who had received off-pump coronary bypass operation in our hospital, and compared with data on those who also had the same two diseases but received on-pump coronary artery bypass at same time. There were no operation-related death; one died of respiratory failure 14 days after operation while staying in hospital; there were more respiratory complications in the conventional coronary artery bypass grafting group (CCABG) than in the OPCABG group; and the PaO2/FiO2 in the CCABG group was higher than that in the OPCABG group during operation because of CPB, but lower than that in the OPCABG group 6-12 hours after operation. OPCABG seemed more suitable than CCABG for coronary artery disease patients with chronic obstructive pulmonary disease due to less damage to their oxygen-exchange capability and the fewer respiratory complications.
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22 articles
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