The germination of pollen grain in vitro and the growth of pollen tube in the pistil of rice were observed with a microscope. The stigma was removed at different time points after pollination to study its effect on se...The germination of pollen grain in vitro and the growth of pollen tube in the pistil of rice were observed with a microscope. The stigma was removed at different time points after pollination to study its effect on seed setting rate. The rice pollen grain started to germinate at 2 min after pollination and the pollen tube penetrated stigma into style in 5-10 min, 30 min later the end of pollen tube reached the bottom of ovary, and only some pollen tubes arrived at embryo sac at 40 min after pollination. Meanwhile, a small amount of callose began to deposit in the pollen tubes, a great deal of callose was observed at 50 min after pollination, whereas the pollen grain began to shrink. The growing rates of pollen tube in the rice stigma, style and ovary were 1500, 5000, and 5400 μm/h, respectively. The seed setting rate was quite low when the stigma was removed at about 10-15 min after pollination, gradually increased when it removed at 20 min to 50 min after pollination, and over 60% when it removed at 50 min after pollination and finally tended to be stable.展开更多
In this article, the functions of D-myo-inositol-1,4,5-trisphosphate (Ins [1,4,5] P3) in regulating pollen tube polar growth were investigated by application of caged version of the phosphoinositides. To increase the ...In this article, the functions of D-myo-inositol-1,4,5-trisphosphate (Ins [1,4,5] P3) in regulating pollen tube polar growth were investigated by application of caged version of the phosphoinositides. To increase the intracellular Ins(1,4,5)P3 concentration at the apical region of pollen tube, the caged Ins(1,4,5)P3 loaded by osmotic shock was activated by 10 s 360 nm UV flash at this domain (10 μm from the tip). More than 70% pollen tubes were induced swelling at apex and/or growth axis reorientation, accompanying temporarily growth arrest, by localized increase of Ins(1,4,5)P3 concentration (n=21). While, pollen tubes without being loaded with caged Ins(1,4,5)P3 had not response to the same dosage UV flash. With FM 1-43 fluorescent staining, it was found that growth perturbation by UV activated caged Ins(1,4,5)P3 had tight link with membrane trafficking at the apical zone of pollen tubes. Upon UV pulse, the apical V-shaped bright area where was full of secretory vesicles spread to a much broader region, which implied that actin filaments at the apical region were remodeled. It was also observed that the FM 1-43 fluorescence intensity at tip remarkably increased than that before UV flash, which demonstrated that more secretory vesicles were accumulated at this region. To estimate the role of Ins(1,4,5)P3 in modulating intracellular calcium concentration and distribution, dextran conjugated fluorescent dye Calcium Green-1 and Rhodamine B were microinjected into pollen tubes together with caged Ins(1,4,5)P3. The results showed that calcium concentration at the subapical region increased upon UV released Ins(1,4,5)P3. Consequently, the tip-focused calcium gradient under the apical dome of pollen tube was disturbed. Simultaneously, the pollen tube bulged at the apical region and its growth rate decreased. As the tip-focused calcium gradient was reestablished, the pollen tube morphology and growth recovered to the normal level. Therefore, Ins(1,4,5)P3 can modulate pollen tube growth rate and direction through mobilizing intracellular calcium and regulating vesicle trafficking during pollen tube finding its way to the ovary.展开更多
[Objective] This study aimed to investigate the influence of different plant growth regulators on apricot pollen germination and pollen tube growth. [Method] Pollens of six kinds of Xinjiang apricots were cultured in ...[Objective] This study aimed to investigate the influence of different plant growth regulators on apricot pollen germination and pollen tube growth. [Method] Pollens of six kinds of Xinjiang apricots were cultured in solid media supplemented with five plant growth regulators (GA3 , NAA, 2, 4-D, 6-BA, IAA). Then the rate of pollen germination and the length of pollen tube were respectively measured. [Result] In a certain concentration range, GA3 most significantly promoted the pollen germination and the pollen tube growth of Shushanggan, Kalayulvke, Dayoujia, Yiliakeyulvke and Kabakehuanna; NNA had the strongest improvement function on Kumaiti’s pollen germination and pollen tube growth. [Conclusion] All the five plant growth regulators promoted the pollen germination and the pollen tube growth of apricots at low concentration but inhibited them at high concentration.展开更多
[Objective] This study aimed to investigate the salt-tolerance mechanism of sweet potato.[Method]Two sweet potato varieties of Xu 25-2(salt-tolerant cultivar)and Triumph 100(salt-sensitive cultivar)were treated by sod...[Objective] This study aimed to investigate the salt-tolerance mechanism of sweet potato.[Method]Two sweet potato varieties of Xu 25-2(salt-tolerant cultivar)and Triumph 100(salt-sensitive cultivar)were treated by sodium chloride with the concentration of 0 mmol/L and 100 mmol/L.After 20 days,Na+ content and Na+/K+ ratio in the roots,shoots and leave were determined by the flame photometer,while dry weight and fresh weight of roots,shoots and leave in different varieties were also studied.[Result]The growth of two sweet potato varieties was inhibited under salt stress,so the plant became shorter,leaf and root became fewer,dry weight of roots and leave decreased,but seedlings of Xu 25-2 were inhibited slightly.Furthermore,Na+ content and Na+/K+ ratio in roots,shoots and leaves of two sweet potato varieties increased.Na+ content of salt-tolerant Xu 25-2 was low in roots,shoots and leaves,while Na+ content of salt-sensitive Triumph 100 was high in shoots and leave of seedlings,but the change range of Xu 25-2 was less than that of Triumph 100.[Conclusion]The lower Na+ content and Na+/K+ ratio in leaves under salt stress were the most important characteristics for salt-tolerance of sweet potato varieties.展开更多
This paper applies techniques of containerless processing, drop tube and glass fluxing, to undercool and solidify Ni77P23 alloys. Different diameter spheres were collected at the bottom of a 52-m long drop tube. Both ...This paper applies techniques of containerless processing, drop tube and glass fluxing, to undercool and solidify Ni77P23 alloys. Different diameter spheres were collected at the bottom of a 52-m long drop tube. Both crystalline and amorphous phase were formed in various size specimens due to the different cooling rate. The variation of partial undercooling with bulk undercooling is calculated for the Ni77P23 alloys. The deep undercooling and rapid solidification behaviour of Ni77P23 melts has been analysed with respect to microstructure formation and transition during fluxing and 52-m drop process of undercooled melts.展开更多
Background: A new rapid Immunochromatographic test (ICT) kit (MPT64 TB Ag Kit) for detection of MPT64 Antigen in M. tuberculosis (MTB) isolates used for rapid identification of MTB isolates developed by SD (Standard D...Background: A new rapid Immunochromatographic test (ICT) kit (MPT64 TB Ag Kit) for detection of MPT64 Antigen in M. tuberculosis (MTB) isolates used for rapid identification of MTB isolates developed by SD (Standard Diagnostics) Bio line, South Korea was evaluated. The ICT is a rapid, reliable and cheaper method that can be used instead of conventional biochemical tests for confirming MTB in culture isolates in resource limited laboratories. The study also evaluated the ability of ICT to detect MPT64-Antigen before the micro MGIT could signal positive. Material/Methods: A total of 450 sputum samples of individual patients were used for the study. 152 isolates of Mycobacteria were recovered from solid and liquid media. These strains were tested for the detection of MPT64-antigen. H37Rv strain was served as the positive reference control and also used for early detection of Antigen experiment. Findings: The development of bands on both test and sample region when H37Rv strain was tested were seen (MPT64 antigen positive). When 138 MTB isolates were tested, it showed a similar banding pattern indicating 100% sensitivity. MPT64 band formation was not detected in any of the 14 isolates indicating 100% specificity. Both PPV & NPV were 100%. All the isolates negative for MPT64 Ag were confirmed as MOTT by conventional bio-chemical PNBA. The H37Rv strain showed a faint band from the 2nd day onwards from inoculation till 3rd day in the earlier Antigen detection experiment. Conclusion: Rapid identification of MTB culture isolate is a pressing need for diagnosis and proceeding to perform drug susceptibility testing. MPT64 TB Ag detection ICT kit is a rapid, reliable method, good substitute for molecular identification methods, and conventional biochemical test which is time-consuming and technically demanding. The early detection of Antigen can be used as an effective tool in diagnosis.展开更多
Objective:To characterize mycobaclerium isolates from pulmomary tuberculosis suspected cases visiting National Tuberculosis Reference Laboratory at Ethiopian Health and Nutrition Research Institute,for diagnosis of pu...Objective:To characterize mycobaclerium isolates from pulmomary tuberculosis suspected cases visiting National Tuberculosis Reference Laboratory at Ethiopian Health and Nutrition Research Institute,for diagnosis of pulmonary tuberculosis from January 4 to February 22.2010 with total samples of 263.Methods:Sputum specimens were collected and processed:the deposits were cultured.Por culturing Lowenstein Jensen medium(LJ) and Mycobacteria Growth Indicator Tube(BACTEC MGIT 960) were used.Capilia Neo was used for detecting NTM isolates from isolates of BACTEC MGIT960.In Armauer Hansen Research Institute,Addis Ababa Ethiopia,Deletion typing PCR method for species identification(from confirmed Mycobacterium tuberculosis complex(MTBC) isolates by Capilia Neo) uas done.Results:Out of 263 enrolled in the study.124 and 117 ol them were positive for mycobaeterium growth by BACTEC MGIT 960 and 1.1 culture method,respectively.From BACTEC MGIT 960 positive media of 124 isolates.117 were randomly taken to perform Capilia TB Neo lest.From these 7(6%) of them were found to be NTM and 110(94%) were MTBC.From these 110 MTBC isolates,81 of them were randomly taken and run by the deletion typing RD9 PCR method of molecular technique.Out of these 78(96.3%) were found to be species of Mycobacterium tuberculosis and 3(3.7%) were found to be not in the MTBC.Regarding the types of methods of culture media.Mycobacteria Growth Indicator Tube(BACTEC MGIT 960) method was found to have excellent agreement(with kappa value ol 0.78) with the routine method of LJ.Conclusions:Pulmonary tuberculosis suspected cases visiting the National Tuberculosis Reference Laboratory at EHNR1 that were confirmed to be pulmonary tuberculosis are caused by the species of Mycobacterium tuberculosis.hence treatment regimen including pyrazinamide can be applied to the patients as the first choice in the study area in Addis Ababa.Ethiopia.There is indication of the presence of NTM in patients visiting the tuberculosis reference laboratory and this is important because NTM is known lo cause pulmonary disease similar with sign and symptom ol pulmonary tuberculosis but different in treatment.BACTEC MGIT 960 has excellent agreement with LJ media but it has high tendency of having high contamination rale unless a better decontamination method is designed.展开更多
It is showed after the furnace tubes serviced for 8-10 years that the density of damage in the HAZ (heat affected zone) of the weld has higher than in parent metals, though the depth of damage is not equal to. By the ...It is showed after the furnace tubes serviced for 8-10 years that the density of damage in the HAZ (heat affected zone) of the weld has higher than in parent metals, though the depth of damage is not equal to. By the test of creep crack growth, it is also acquired that under same mechanic parameter C* (t), the rate of creep crack growth in the HAZ is more than twice as fast as in parent metals. Two mechanisms (overheating and thermal shock) of failure occurred in an accident are presented. The stress of thermal shock is analyzed, in which the change of the elasticity modulus with the radius ET = /(r) is considered. Based on it, the safety region of the thermal shock is obtained. Finally, two sets of curves for the safe life are suggested which can facilitate to estimate the remaining life of HK-40 or HP-Nb tubes by their creep rupture data.展开更多
Objective:To investigate the effect and mechanism of miRNA-24 on the proliferation,migration and tube formation of vascular endothelial cells.Methods:Human umbilical vein endothelial cells(HUVECs)were assigned into co...Objective:To investigate the effect and mechanism of miRNA-24 on the proliferation,migration and tube formation of vascular endothelial cells.Methods:Human umbilical vein endothelial cells(HUVECs)were assigned into control,microRNA(miR)-24 overexpression and anti-miR-24 groups.The proliferation and migration abilities of HUVECs were detected by methyl thiazolyl tetrazolium(MTT)assay and scratch wound healing assay,respectively.The ability of HUVECs to form tubular structures was evaluated by a tube formation assay.The mRNA and protein expressions of vascular endothelial growth factor(VEGF)and transcription factor Sp1 were determined by RT-PCR,immunocytochemistry and western blotting,respectively.Results:The miR-24 overexpression group exhibited decreased cell proliferation and migration,and expressions of VEGF and Sp1 compared with the control group(P <0.01).No tube-like network structure was formed in the miR-24 overexpression group.However,inhibition of miR-24 in HUVECs markedly increased cell proliferation and migration,enhanced tube formation and expressions of VEGF and Sp1(P<0.05 or P<0.01).Conclusion:MiR-24 suppressed the proliferation,migration and tube formation of HUVECs,and the mechanism might be related to the down-regulation of VEGF expression.Sp1 might participate in this regulation process.展开更多
A capillary-enforced template-based method has been applied to fabricate calcium copper titanate (CaCu3Ti4O12, CCTO) nanotubes (diameter ~200 nm) by filling sol-gel CCTO precursor solution into the nanochannels of por...A capillary-enforced template-based method has been applied to fabricate calcium copper titanate (CaCu3Ti4O12, CCTO) nanotubes (diameter ~200 nm) by filling sol-gel CCTO precursor solution into the nanochannels of porous anodic aluminum oxide (AAO) templates, subsequent heating for phase formation and fi- nally the removal of nano-channel templates by applying basic solution. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) equipped with Energy-dispersive X-ray spectroscopy (EDX) have been employed to characterize the morphology, structure, and composition of as-prepared nanotubes. XRD and selected-area electron diffraction (SAED) in-vestigations demonstrated that postannealed (750○C for 1 h) CCTO nanotubes were poly-crystalline with a cubic pseudo-perovskite cry- stal structure. The FE-SEM and TEM results showed that CCTO nanotubes were of uniform diameter (~200 nm) throughout their length. High resolution TEM (HRTEM) analysis confirm- ed that the obtained CCTO nanotubes are made of randomly aligned nano-particles 5-10 nm in size. EDX analysis demonstrated that stoichi- ometric CaCu3Ti4O12 was formed. The possible formation mechanism of CCTO nanotubes in the AAO template is discussed.展开更多
A design for an air-cooled test tube, with a series of modular and movable rings (cylindrical “crystallization comb”), installed in a laboratory crucible furnace is presented. The setup allows easy regulation simult...A design for an air-cooled test tube, with a series of modular and movable rings (cylindrical “crystallization comb”), installed in a laboratory crucible furnace is presented. The setup allows easy regulation simultaneous crystallization tests of a series of different crystallization rates in several columns (matrix) of test tubes, enabling fast studies of obtaining crystals. This low-budget, portable device (i.e. adjustable airstream with more simple control options), can also be applied in tube and chamber furnaces. The relations between the crystallization rate and parameters of air-cooled test tube are given and numerically analyzed.展开更多
AIMTo determine whether small interfering RNA (siRNA) of PGC-1α could inhibit vascular endothelial growth factor (VEGF) expression and tube formation in human retinal vascular endothelial cells (hRVECs).ME...AIMTo determine whether small interfering RNA (siRNA) of PGC-1α could inhibit vascular endothelial growth factor (VEGF) expression and tube formation in human retinal vascular endothelial cells (hRVECs).METHODShRVECs transfected with peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) siRNA were incubated for 24h and then placed into a normoxic (20%, O<sub>2</sub>) or hypoxic (1%, O<sub>2</sub>) environment for another 16h. PGC-1α mRNA and protein levels were detected by real-time PCR and Western blot. VEGF mRNA and protein levels were detected by real-time PCR and ELISA. Cell proliferation was evaluated by BrdU incorporation assay. Forty-eight hours after siRNA transfection, hRVECs were planted into Matrigel-coated plates and cultured under normoxic (20%, O<sub>2</sub>) or hypoxic (1%, O<sub>2</sub>) conditions for another 48h. The tube formation of hRVECs was observed under an optical microscope and quantified by counting the number of branch points and calculating the total tube length.RESULTSPGC-1α mRNA and protein levels were significantly reduced by PGC-1α siRNA, and VEGF mRNA and protein levels also decreased significantly. The percentage of BrdU-labeled cells in siPGC-1α groups were significantly decreased compared with control siRNA groups under normoxia and hypoxia in cell proliferation assay. In the tube formation assay, PGC-1α siRNA treated cells formed significantly fewer tubes.CONCLUSIONBlocking PGC-1α expression can inhibit VEGF expression in hRVECs and inhibit their ability to form tubes under both normoxic and hypoxic conditions.展开更多
基金the National Natural Science Foundation of China (Grants Nos. 30070454 and 30471045)
文摘The germination of pollen grain in vitro and the growth of pollen tube in the pistil of rice were observed with a microscope. The stigma was removed at different time points after pollination to study its effect on seed setting rate. The rice pollen grain started to germinate at 2 min after pollination and the pollen tube penetrated stigma into style in 5-10 min, 30 min later the end of pollen tube reached the bottom of ovary, and only some pollen tubes arrived at embryo sac at 40 min after pollination. Meanwhile, a small amount of callose began to deposit in the pollen tubes, a great deal of callose was observed at 50 min after pollination, whereas the pollen grain began to shrink. The growing rates of pollen tube in the rice stigma, style and ovary were 1500, 5000, and 5400 μm/h, respectively. The seed setting rate was quite low when the stigma was removed at about 10-15 min after pollination, gradually increased when it removed at 20 min to 50 min after pollination, and over 60% when it removed at 50 min after pollination and finally tended to be stable.
文摘In this article, the functions of D-myo-inositol-1,4,5-trisphosphate (Ins [1,4,5] P3) in regulating pollen tube polar growth were investigated by application of caged version of the phosphoinositides. To increase the intracellular Ins(1,4,5)P3 concentration at the apical region of pollen tube, the caged Ins(1,4,5)P3 loaded by osmotic shock was activated by 10 s 360 nm UV flash at this domain (10 μm from the tip). More than 70% pollen tubes were induced swelling at apex and/or growth axis reorientation, accompanying temporarily growth arrest, by localized increase of Ins(1,4,5)P3 concentration (n=21). While, pollen tubes without being loaded with caged Ins(1,4,5)P3 had not response to the same dosage UV flash. With FM 1-43 fluorescent staining, it was found that growth perturbation by UV activated caged Ins(1,4,5)P3 had tight link with membrane trafficking at the apical zone of pollen tubes. Upon UV pulse, the apical V-shaped bright area where was full of secretory vesicles spread to a much broader region, which implied that actin filaments at the apical region were remodeled. It was also observed that the FM 1-43 fluorescence intensity at tip remarkably increased than that before UV flash, which demonstrated that more secretory vesicles were accumulated at this region. To estimate the role of Ins(1,4,5)P3 in modulating intracellular calcium concentration and distribution, dextran conjugated fluorescent dye Calcium Green-1 and Rhodamine B were microinjected into pollen tubes together with caged Ins(1,4,5)P3. The results showed that calcium concentration at the subapical region increased upon UV released Ins(1,4,5)P3. Consequently, the tip-focused calcium gradient under the apical dome of pollen tube was disturbed. Simultaneously, the pollen tube bulged at the apical region and its growth rate decreased. As the tip-focused calcium gradient was reestablished, the pollen tube morphology and growth recovered to the normal level. Therefore, Ins(1,4,5)P3 can modulate pollen tube growth rate and direction through mobilizing intracellular calcium and regulating vesicle trafficking during pollen tube finding its way to the ovary.
基金Supported by Key Technology Integration and Demonstration of Xinjiang Characteristic Fruit Trees'High Efficiency and Safe Production,Science and Technical Plan Project of Xinjiang Uygur Autonomous Region(201130102)Key Technology Integration and Demonstration of Xinjiang Apricot Industrial Development,Science and Technical Plan Project of Xinjiang Uygur Autonomous Region(200931101)Financial Support from Xinjiang Uygur Autonomous Region Fruit Trees Key Subject~~
文摘[Objective] This study aimed to investigate the influence of different plant growth regulators on apricot pollen germination and pollen tube growth. [Method] Pollens of six kinds of Xinjiang apricots were cultured in solid media supplemented with five plant growth regulators (GA3 , NAA, 2, 4-D, 6-BA, IAA). Then the rate of pollen germination and the length of pollen tube were respectively measured. [Result] In a certain concentration range, GA3 most significantly promoted the pollen germination and the pollen tube growth of Shushanggan, Kalayulvke, Dayoujia, Yiliakeyulvke and Kabakehuanna; NNA had the strongest improvement function on Kumaiti’s pollen germination and pollen tube growth. [Conclusion] All the five plant growth regulators promoted the pollen germination and the pollen tube growth of apricots at low concentration but inhibited them at high concentration.
基金Supported by the National Natural Science Foundation(30670177)Scientific Research Foundation for the Outstanding Young Scientist of Shangdong Province(006BS06002)National Ministry of Education Doctoral Fund(20050445003)~~
文摘[Objective] This study aimed to investigate the salt-tolerance mechanism of sweet potato.[Method]Two sweet potato varieties of Xu 25-2(salt-tolerant cultivar)and Triumph 100(salt-sensitive cultivar)were treated by sodium chloride with the concentration of 0 mmol/L and 100 mmol/L.After 20 days,Na+ content and Na+/K+ ratio in the roots,shoots and leave were determined by the flame photometer,while dry weight and fresh weight of roots,shoots and leave in different varieties were also studied.[Result]The growth of two sweet potato varieties was inhibited under salt stress,so the plant became shorter,leaf and root became fewer,dry weight of roots and leave decreased,but seedlings of Xu 25-2 were inhibited slightly.Furthermore,Na+ content and Na+/K+ ratio in roots,shoots and leaves of two sweet potato varieties increased.Na+ content of salt-tolerant Xu 25-2 was low in roots,shoots and leaves,while Na+ content of salt-sensitive Triumph 100 was high in shoots and leave of seedlings,but the change range of Xu 25-2 was less than that of Triumph 100.[Conclusion]The lower Na+ content and Na+/K+ ratio in leaves under salt stress were the most important characteristics for salt-tolerance of sweet potato varieties.
基金Project supported by Hebei province Natural Science Foundation of China (Grant No A200700296)National Natural Science Foundation of China (Grant No 50731005)National Basic Research Program of China (Grant No 2007CB616915/2006CB605201)
文摘This paper applies techniques of containerless processing, drop tube and glass fluxing, to undercool and solidify Ni77P23 alloys. Different diameter spheres were collected at the bottom of a 52-m long drop tube. Both crystalline and amorphous phase were formed in various size specimens due to the different cooling rate. The variation of partial undercooling with bulk undercooling is calculated for the Ni77P23 alloys. The deep undercooling and rapid solidification behaviour of Ni77P23 melts has been analysed with respect to microstructure formation and transition during fluxing and 52-m drop process of undercooled melts.
文摘Background: A new rapid Immunochromatographic test (ICT) kit (MPT64 TB Ag Kit) for detection of MPT64 Antigen in M. tuberculosis (MTB) isolates used for rapid identification of MTB isolates developed by SD (Standard Diagnostics) Bio line, South Korea was evaluated. The ICT is a rapid, reliable and cheaper method that can be used instead of conventional biochemical tests for confirming MTB in culture isolates in resource limited laboratories. The study also evaluated the ability of ICT to detect MPT64-Antigen before the micro MGIT could signal positive. Material/Methods: A total of 450 sputum samples of individual patients were used for the study. 152 isolates of Mycobacteria were recovered from solid and liquid media. These strains were tested for the detection of MPT64-antigen. H37Rv strain was served as the positive reference control and also used for early detection of Antigen experiment. Findings: The development of bands on both test and sample region when H37Rv strain was tested were seen (MPT64 antigen positive). When 138 MTB isolates were tested, it showed a similar banding pattern indicating 100% sensitivity. MPT64 band formation was not detected in any of the 14 isolates indicating 100% specificity. Both PPV & NPV were 100%. All the isolates negative for MPT64 Ag were confirmed as MOTT by conventional bio-chemical PNBA. The H37Rv strain showed a faint band from the 2nd day onwards from inoculation till 3rd day in the earlier Antigen detection experiment. Conclusion: Rapid identification of MTB culture isolate is a pressing need for diagnosis and proceeding to perform drug susceptibility testing. MPT64 TB Ag detection ICT kit is a rapid, reliable method, good substitute for molecular identification methods, and conventional biochemical test which is time-consuming and technically demanding. The early detection of Antigen can be used as an effective tool in diagnosis.
文摘Objective:To characterize mycobaclerium isolates from pulmomary tuberculosis suspected cases visiting National Tuberculosis Reference Laboratory at Ethiopian Health and Nutrition Research Institute,for diagnosis of pulmonary tuberculosis from January 4 to February 22.2010 with total samples of 263.Methods:Sputum specimens were collected and processed:the deposits were cultured.Por culturing Lowenstein Jensen medium(LJ) and Mycobacteria Growth Indicator Tube(BACTEC MGIT 960) were used.Capilia Neo was used for detecting NTM isolates from isolates of BACTEC MGIT960.In Armauer Hansen Research Institute,Addis Ababa Ethiopia,Deletion typing PCR method for species identification(from confirmed Mycobacterium tuberculosis complex(MTBC) isolates by Capilia Neo) uas done.Results:Out of 263 enrolled in the study.124 and 117 ol them were positive for mycobaeterium growth by BACTEC MGIT 960 and 1.1 culture method,respectively.From BACTEC MGIT 960 positive media of 124 isolates.117 were randomly taken to perform Capilia TB Neo lest.From these 7(6%) of them were found to be NTM and 110(94%) were MTBC.From these 110 MTBC isolates,81 of them were randomly taken and run by the deletion typing RD9 PCR method of molecular technique.Out of these 78(96.3%) were found to be species of Mycobacterium tuberculosis and 3(3.7%) were found to be not in the MTBC.Regarding the types of methods of culture media.Mycobacteria Growth Indicator Tube(BACTEC MGIT 960) method was found to have excellent agreement(with kappa value ol 0.78) with the routine method of LJ.Conclusions:Pulmonary tuberculosis suspected cases visiting the National Tuberculosis Reference Laboratory at EHNR1 that were confirmed to be pulmonary tuberculosis are caused by the species of Mycobacterium tuberculosis.hence treatment regimen including pyrazinamide can be applied to the patients as the first choice in the study area in Addis Ababa.Ethiopia.There is indication of the presence of NTM in patients visiting the tuberculosis reference laboratory and this is important because NTM is known lo cause pulmonary disease similar with sign and symptom ol pulmonary tuberculosis but different in treatment.BACTEC MGIT 960 has excellent agreement with LJ media but it has high tendency of having high contamination rale unless a better decontamination method is designed.
文摘It is showed after the furnace tubes serviced for 8-10 years that the density of damage in the HAZ (heat affected zone) of the weld has higher than in parent metals, though the depth of damage is not equal to. By the test of creep crack growth, it is also acquired that under same mechanic parameter C* (t), the rate of creep crack growth in the HAZ is more than twice as fast as in parent metals. Two mechanisms (overheating and thermal shock) of failure occurred in an accident are presented. The stress of thermal shock is analyzed, in which the change of the elasticity modulus with the radius ET = /(r) is considered. Based on it, the safety region of the thermal shock is obtained. Finally, two sets of curves for the safe life are suggested which can facilitate to estimate the remaining life of HK-40 or HP-Nb tubes by their creep rupture data.
基金supported by the National Natural Science Foundation of China(No.81373403)
文摘Objective:To investigate the effect and mechanism of miRNA-24 on the proliferation,migration and tube formation of vascular endothelial cells.Methods:Human umbilical vein endothelial cells(HUVECs)were assigned into control,microRNA(miR)-24 overexpression and anti-miR-24 groups.The proliferation and migration abilities of HUVECs were detected by methyl thiazolyl tetrazolium(MTT)assay and scratch wound healing assay,respectively.The ability of HUVECs to form tubular structures was evaluated by a tube formation assay.The mRNA and protein expressions of vascular endothelial growth factor(VEGF)and transcription factor Sp1 were determined by RT-PCR,immunocytochemistry and western blotting,respectively.Results:The miR-24 overexpression group exhibited decreased cell proliferation and migration,and expressions of VEGF and Sp1 compared with the control group(P <0.01).No tube-like network structure was formed in the miR-24 overexpression group.However,inhibition of miR-24 in HUVECs markedly increased cell proliferation and migration,enhanced tube formation and expressions of VEGF and Sp1(P<0.05 or P<0.01).Conclusion:MiR-24 suppressed the proliferation,migration and tube formation of HUVECs,and the mechanism might be related to the down-regulation of VEGF expression.Sp1 might participate in this regulation process.
文摘A capillary-enforced template-based method has been applied to fabricate calcium copper titanate (CaCu3Ti4O12, CCTO) nanotubes (diameter ~200 nm) by filling sol-gel CCTO precursor solution into the nanochannels of porous anodic aluminum oxide (AAO) templates, subsequent heating for phase formation and fi- nally the removal of nano-channel templates by applying basic solution. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) equipped with Energy-dispersive X-ray spectroscopy (EDX) have been employed to characterize the morphology, structure, and composition of as-prepared nanotubes. XRD and selected-area electron diffraction (SAED) in-vestigations demonstrated that postannealed (750○C for 1 h) CCTO nanotubes were poly-crystalline with a cubic pseudo-perovskite cry- stal structure. The FE-SEM and TEM results showed that CCTO nanotubes were of uniform diameter (~200 nm) throughout their length. High resolution TEM (HRTEM) analysis confirm- ed that the obtained CCTO nanotubes are made of randomly aligned nano-particles 5-10 nm in size. EDX analysis demonstrated that stoichi- ometric CaCu3Ti4O12 was formed. The possible formation mechanism of CCTO nanotubes in the AAO template is discussed.
文摘A design for an air-cooled test tube, with a series of modular and movable rings (cylindrical “crystallization comb”), installed in a laboratory crucible furnace is presented. The setup allows easy regulation simultaneous crystallization tests of a series of different crystallization rates in several columns (matrix) of test tubes, enabling fast studies of obtaining crystals. This low-budget, portable device (i.e. adjustable airstream with more simple control options), can also be applied in tube and chamber furnaces. The relations between the crystallization rate and parameters of air-cooled test tube are given and numerically analyzed.
基金Supported by National Natural Science Fundation of China(No.81000387)
文摘AIMTo determine whether small interfering RNA (siRNA) of PGC-1α could inhibit vascular endothelial growth factor (VEGF) expression and tube formation in human retinal vascular endothelial cells (hRVECs).METHODShRVECs transfected with peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) siRNA were incubated for 24h and then placed into a normoxic (20%, O<sub>2</sub>) or hypoxic (1%, O<sub>2</sub>) environment for another 16h. PGC-1α mRNA and protein levels were detected by real-time PCR and Western blot. VEGF mRNA and protein levels were detected by real-time PCR and ELISA. Cell proliferation was evaluated by BrdU incorporation assay. Forty-eight hours after siRNA transfection, hRVECs were planted into Matrigel-coated plates and cultured under normoxic (20%, O<sub>2</sub>) or hypoxic (1%, O<sub>2</sub>) conditions for another 48h. The tube formation of hRVECs was observed under an optical microscope and quantified by counting the number of branch points and calculating the total tube length.RESULTSPGC-1α mRNA and protein levels were significantly reduced by PGC-1α siRNA, and VEGF mRNA and protein levels also decreased significantly. The percentage of BrdU-labeled cells in siPGC-1α groups were significantly decreased compared with control siRNA groups under normoxia and hypoxia in cell proliferation assay. In the tube formation assay, PGC-1α siRNA treated cells formed significantly fewer tubes.CONCLUSIONBlocking PGC-1α expression can inhibit VEGF expression in hRVECs and inhibit their ability to form tubes under both normoxic and hypoxic conditions.