1.Basic study of fabricating dental prosthesis with laser engineered net shaping (LENS) method-The mechanical properties of LENS components made from Rene95 alloy
Bo GAO ; Yanmin LI ; Jing CHEN
Journal of Practical Stomatology 2001;0(03):-
Objective: To evaluate the mechanical properties of Rene95 alloy component made by laser engineered net shaping (LENS). Methods: The component was fabricated from Rene95 alloy powder by LENS, then the mechanical properties of the component, Rene95 alloy casting and dental Ni-Cr alloy casting were studied. Results: The tensile strength(MPa), yield strength(MPa), elongations(%) and the microhardness(Hv) of Rene 95 alloy component made by LENS were 1 354.27?63.44, 1 175.29?34.32, 16.53?5.85, and 464.33?10.95, those of Rene95 alloy casting 1 430.28?55.73, 1 145.52?29.78, 10.31?4.25 and 457.56? 11.38, those of dental Ni-Cr alloy casting 612.05?18.46, 426.06?12.70, 6.21?1.21 and 260.14? 6.08, respectively.Conclusion: The mechanical properties of Rene95 alloy component made by LENS were same as those of Rene95 alloy casting, better than dental Ni-Cr alloy casting.
2.Basic study of fabricating dental prosthesis with laser engineered net shaping (LENS) method——The microstructure of LENS components made from Rene95 alloy
Bo GAO ; Yanmin LI ; Jing CHEN
Journal of Practical Stomatology 2000;0(06):-
objective: To study the effects of laser engineered net shaping(LENS) in the manufacture of dental prosthesis. Methods: An experiment LENS system, including a 5 kW continuous wave CO 2 laser, a four-axes numerical control working table and powder feeding system, was built up, by which, a rectangular LENS component was made from Rene95 alloy powder. The microstructure of the component was observed with scanning electron microscope and ESA analysis. Results: The size of the component was 120 mm?15 mm?15 mm , and the wall of the component was perpendicular to the base. The microstructure of the component was made up of fine columnar dendrite with the length of 10~20 ?m, 10 times less than that of the cast made from the same material. The main elements of the powder distributed homogeneously,the negative effect of segregation could be limited and the properties of the component could be improved.Conclusion: The microstructure of components made by LENS is much better than that of those made by casting from the same material.
3.Construction of pRluc-hNTSR1-pcDNA3.1 eukaryotic expression vectors and its expression in isolated cells
Chinese Journal of Behavioral Medicine and Brain Science 2011;20(12):1140-1142
Objective To construct expression vectors that Renilla reniformis (Rluc) fused with neurotensin type 1 receptor (NTSR1),and to investigate the interaction between NTSR1 and other receptors,as well as intercellular signal transduction mechanism mediated by neurotensinl-R.Methods The human NTSR1 gene was amplified by PCR using the plasmid pcDNA3.1-hNTSR1 as template.The PCR product was digested,ligased with the plasmid pRluc and then be transformed into the competent cell Top10.The construct was identified by DNA sequencing.The recombinant plasmid was transiently transfected into human embryonic kidney 293 ( HEK293 )cells,and the expression of pRluc-hNTSR1-pcDNA3.1 was detected by confocal microscopy and Western blot.Results The fragment of 1257 bp was amplified by PCR,and the DNA sequences were identical with the gene in GenBank ( NM_002531 ).Western blot showed a band about 90kDa.Confocal microscopy showed that NTSR1 was expressed on the plasma membrane.Conclusion The pRluc-hNTSR1-pcDNA3.1 eukaryotic expression vector is successfully constructed,and the expression vector can be used to investigate the interaction between NTSR1 and other receptors,as well as intercellular signal transduction mechanism mediated by neurotensinl-R,which will provide new target for drug development.
4.Corrosion behavior of Ti-Zr alloy formed by laser solid forming technology
Bo GAO ; Xiaodong YAN ; Jing CHEN
Journal of Practical Stomatology 2001;0(03):-
Objective:To evaluate the anti-corrosion property of Ti-Zr alloy fabricated by laser solid forming technic in artificial saliva.Method:The corrosive behavior of Ti-Zr alloy fabricated by laser solid forming was studied by potentiadynamic polarization technique in artificial saliva at 37 ℃(pH=6.8).Ti-Zr alloy formed by casting was applied as the control.With the polarization curves given by the electrochemical corrosive measure system and the picture of corrosive plane given by SEM, the corrosive property of the Ti-Zr alloy were analyzed.Results:Ti-Zr alloy fabricated by laser solid forming showed more relatively positive corrosion potential, smaller corrosion current density and lower passive potential, and did not show any evidence of corrosive phenomena.Conclusion:Ti-Zr alloy fabricated by laser solid forming has good corrosive resistance in oral circumstances.
5.Analysis on the Utilization of Cardiovascular and Cerebrovascular Drugs in a Military Sanatorium During 2007~2009
Jing LING ; Fangfang LU ; Bo CHEN
China Pharmacy 2001;0(12):-
OBJECTIVE: To analyze the use situation and trend of cardiovascular and cerebrovascular drugs during 2007~2009 in a military sanatorium, and provide reference for the rational use of cardiovascular and cerebrovascular drugs and its essential medicines. METHODS: Cardiovascular and cerebrovascular drugs in the rehabilitation center during 2007~2009 were analyzed statistically in the respect of category, consumption sum and DDDs. RESULTS: The consumption sum and DDDs of cardiovascular and cerebrovascular drugs were increasing in the past three years. And its essential drugs account for 94.8%.The most widely used drugs were cerebrovascular drug, brain metabolism drug, nootropics and antihypertensive drugs. Oxiracetam and Xueshuantong were widely used cerebrovascular drug, brain metabolism drug and nootropics. Amlodipine were widely used antihypertensive drugs in the clinic. CONCLUSION: Cardiovascular and cerebrovascular drugs and its essential drugs were characterized with complex classification, numerous categories, extensive application and potential market demand, which require rational use of drug should be strengthened.
6.Up-regulation of Nrf2 pathway and intervention of intracellular redox homeostasis in shikonin-induced A549 cell apoptosis
Chen XIE ; Hanying CHEN ; Jing ZHONG ; Xiaoqin WANG ; Bo ZHANG
Chinese Pharmacological Bulletin 2014;(10):1445-1451
Aim To investigate the roles of intracellu-lar reactive oxygen species ( ROS ) and Nrf2 pathway in shikonin-induced A549 cell apoptosis. Methods The cytotoxicity was analyzed by MTT assay. The ap-optosis of A549 cells was analyzed by both cellular morphological and biochemical methods. The relative changes of the redox marks ( ROS/GSH) were studied by fluorescence assay in the shikonin-treated A549 cells in accompany with the changes of the intracellular redox homeostasis by GSH/GSSG ratio. ROS inhibitor was also employed in the treatment to find the role of ROS in shikonin-induced A549 cell apoptosis. Real-time PCR analysis and ELISA assay were performed as well to determine the role of Nrf2 pathway in the shiko-nin-induced A549 cell apoptosis. Results The IC50 of shikonin on A549 cells was 3. 2 mg·L-1 . The cellu-lar redox homeostasis shifted toward oxidation signifi-cantly in shikonin treatment in a time-dependent man-ner. The expression of the Nrf2 pathway related genes was up-regulated by shikonin ( 3 . 2 mg · L-1 , 8 h ) . The expression of the anti-apoptotic genes was down-regulated , and proapoptotic genes were up-regulated by shikonin (3. 2 mg·L-1, 24h). Futhermore, the inhi-bition of intracellular ROS alleviated the cytotoxicity of shikonin in A549 cells. Conclusion The critical role of shikonin-induced redox imblance in A549 cell, coped with the secondary produced ROS and Nrf2 path-way antioxidants, result in A549 cell apoptosis.
7.Expression of MIP-3? gene regulated by irradiation via Egr-1 promotor in Lewis lung cancer
Lan ZOU ; Bo ZHU ; Jing CHEN ; Jianping DU ; Zhengtan CHEN
Journal of Third Military Medical University 2003;0(24):-
Objective To construct the expression vector of early growth response-1 promoter-macrophage inflammatory protein 3? (pEgr-1-MIP-3?, pEM) to study MIP-3? expression in transfected Lewis lung cancer cells. Methods MIP-3? cDNA was inserted into plasmid with Egr-1 promoter by directional cloning. The vectors were transfected into Lewis lung cancer cells with liposomes. The expression of MIP-3? in transfected Lewis lung cancer cells induced by electron ray irradiation at different doses were confirmed by RT-PCR and Western blotting. Results The recombinant vector was sequenced, and the result indicated the correct insertion in the expression vector. After electron ray irradiation at different doses, MIP-3? expression in the transfected Lewis lung cancer cells increased significantly. Conclusion Electron ray can enhance the expression of MIP-3? in Lewis lung cancer cells. This has laid the experimental foundation for the studies of pEM for radio-genetic therapy in vivo.
8.Engineering of the xylose metabolic pathway for microbial production of bio-based chemicals.
Weixi LIU ; Jing FU ; Bo ZHANG ; Tao CHEN
Chinese Journal of Biotechnology 2013;29(8):1161-1172
As the rapid development of economy necessitates a large number of oil, the contradiction between energy supply and demand is further exacerbated by the dwindling reserves of petroleum resource. Therefore, the research of the renewable cellulosic biomass resources is gaining unprecedented momentum. Because xylose is the second most abundant monosaccharide after glucose in lignocellulose hydrolyzes, high-efficiency bioconversion of xylose becomes one of the vital factors that affect the industrial prospects of lignocellulose application. According to the research progresses in recent years, this review summarized the advances in bioconversion of xylose, which included identification and redesign of the xylose metabolic pathway, engineering the xylose transport pathway and bio-based chemicals production. In order to solve the energy crisis and environmental pollution issues, the development of advanced bio-fuel technology, especially engineering the microbe able to metabolize xylose and produce ethanol by synthetic biology, is environmentally benign and sustainable.
Bacteria
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genetics
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metabolism
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Escherichia coli
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genetics
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metabolism
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Ethanol
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metabolism
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Fermentation
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Fungi
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genetics
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metabolism
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Industrial Microbiology
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methods
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Metabolic Engineering
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Metabolic Networks and Pathways
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genetics
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Saccharomyces cerevisiae
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genetics
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metabolism
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Xylose
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metabolism
9.Effect of electroacupuncture on brain cells apoptosis and nerve function recovery after focal cerebral ischemia-reperfusion in rats
Haiying WANG ; Qiuling ZHANG ; Jinguo LI ; Jing CHEN ; Bo BAI
Chinese Journal of Behavioral Medicine and Brain Science 2010;19(6):510-512
Objective To investigate the influence of acpuncture on free calcium in rat brain cells after focal cerebral ischemia reperfusion.Methods 145 adult male SD rats were randomly divided into control group,simple ischemia reperfusion group and acupuncture with ischemia reperfusion group.The middle cerebral artery occlusion/reperfusion (MCAO/R) rat model was established by the modified Longa occlusion method. ①The part of free calcium in rat brain cells,focal cevebral ischemia model of rats were made by thread locking up the blood vessel for 15 min.30 min later after reperfusion, the Baihui and Shuigou Point in Du meridian were acupunctured electrically 30 min.After 3h, 6h and 12h, the rat was killed and its brain cells were made into single cell suspension,marked by Fluo-3/AM.The fluorescence optical density was recorded by laser confocal microscopy.②The part of nerve functional reconstruction, focal cevebral ischemia model of rats were made by thread locking up the blood vessel for 12 hours.30 min later after reperfusion, the Baihui and Shuigou Point in Du meridian were acupunctured electrically 30 min.After 7 d, 14 d,30 d,60 d and 90 d, the rat was forced to detect it's strength of the dog.Results ①Free calcium in rats of acupuncture therapy group(6h:10.96±1.18;2h:20.9±4.37) was significantly less than that in control group in 6 h and 12 h after reperfusion (6 h: 16.87 ± 3.56,12 h: 34.10 ±1.06)(P<0.05).②The dog in rats of acupuncture therapy group was significantly more than that in control group in 7 d, 14 d after reperfusion (P< 0.05 ).No difference of the dog was detected in 30 d ,60 d and 90 d after reperfusion between the two groups.Conclusion Acupunture could decreases the concentration of free calcium and the expression of Caspase-3 mRNA in rat brain cells after focal cerebral ischemia reperfusion, and it can facilitate the recovery of nerve function.
10.Bifidobacterium: Re-evaluation from Microecological Point of View
Yihong CHEN ; Jing ZHANG ; Di WU ; Bo WANG ; Xuemei QU
Chinese Journal of Nosocomiology 2006;0(06):-
OBJECTIVE To re-evaluate Bifidobacterium from microecological point of view. METHODS With the development of microecology,it is paid more and more attention to the medical field.The genesis and development of diseases were closely related with microbe imbalance.As a kind of common microbial population in intestinal tract,Bifidobacterium are one of the most important sources for the exploitation of microecological preparation.Bifidobacterium were re-evaluated by the reference review method. RESULTS This review is focused on the current situation,bioactivity,clinical application,and prospective of Bifidobacterium. CONCLUSIONS Bifidobacterium have good application prospects.