Objective In kinesin-3,the neck coil correlates with the following segments to form an extended neck that contains a characteristic hinge diverse from a proline in KIF13B to a long flexible linker in KIF1A.The functio...Objective In kinesin-3,the neck coil correlates with the following segments to form an extended neck that contains a characteristic hinge diverse from a proline in KIF13B to a long flexible linker in KIF1A.The function of this neck hinge for controlling processive movement,however,remains unclear.Methods We made a series of modifications to the neck hinges of KIF13B and KIF1A and tested their movement using a single-molecule motility assay.Results In KIF13B,the insertion of flexible residues before or after the proline differentially impacts the processivity or velocity,while the removal of this proline increases the both.In KIF1A,the deletion of entire flexible neck hinge merely enhances the processivity.The engineering of these hinge-truncated necks of kinesin-3 into kinesin-1 similarly boosts the processive movement of kinesin-1.Conclusion The neck hinge in kinesin-3 controls its processive movement and proper modifications tune the motor motility,which provides a novel strategy to reshape the processive movement of kinesin motors.展开更多
[Objective]The aim was to examine the anti heptocarcinoma effects of human interleukin-12（hIL-12） from transgenic potatoes.[Method]Human heptocarcinoma cell line HepG22.2.15 was cocultured with human peripherial blo...[Objective]The aim was to examine the anti heptocarcinoma effects of human interleukin-12（hIL-12） from transgenic potatoes.[Method]Human heptocarcinoma cell line HepG22.2.15 was cocultured with human peripherial blood monocyte（PBMC）.Human IL-12 extracted from its transgenic patatoes was introduced to this coculture system.MTT method and laser confocal microscope were then employed to evaluate its survival rates and morphological changes of HepG22.2.15 cell line.[Result]The HepG22.2.15 survival rate of the plant produced hIL-12 treated group was significantly lower than that of the wild type control,while similar to that of commercial purified recombinant hIL-12 group.As indicated by AnnexinV/PI double staining laser confocal microscope,cocultured heptocarcinoma cells showed the typical early and final phase apoptotic morphological characteristics 48 hours after 2 × 10-4 mg/L potato secreted hIL-12 treatment.[Conclusion] These results demonstrated that Heptocarcinoma HepG22.2.15 cell growth could be actively inhibited by the transgenic potato expressed hIL-12 in vitro.展开更多
[Objective] This study aimed to investigate the dynamic changes of vegetation cover and its prediction method. [Method] The NDVl was used as data source to perform the spatial overlay analysis on the vegetation covera...[Objective] This study aimed to investigate the dynamic changes of vegetation cover and its prediction method. [Method] The NDVl was used as data source to perform the spatial overlay analysis on the vegetation coverage changes of the study area in different time period under the GIS platform, with the aim to reveal the spatial distribution rules of the vegetation cover in Eastern Jilin Province during the recent 10 years. The Markov Model and Grey System G （1, 1） theory model were used to predict the vegetation cover change trend in Eastern Jilin Province. [Result] The vegetation cover increased a little, but staying stable in general. The regions with great changes were mainly around the lake and river. The prediction results of Markov Model and Grey System G （1, 1） theory model were consistent with the observed measurement. [Conclusion] This study provided referential basis for the effective protection of the vegetation coverage in mountainous forest, and important reference value for the scientific decision-making on the forest construction planning in Jilin Province as well as in China and sustainable development of social economy.展开更多
[Objective] This research aimed to solve the problems of growth and differentiation inhibition of transgenic potato plants caused by antibiotics used for bacteriostasis. [Method] Microtubers were induced using transge...[Objective] This research aimed to solve the problems of growth and differentiation inhibition of transgenic potato plants caused by antibiotics used for bacteriostasis. [Method] Microtubers were induced using transgenic potato plants, which had generated shoots and formed transgenic bacteria-free plants. [Result] Among the three transgenic potato varieties, the optimal induction medium for SⅠ and SⅡ were MS＋ 0.5 mg/L of 6-BA ＋ 0.1 mg/L of GA3＋ 150 mg/L of cef, and the optimal induction medium for NT were MS＋ 0.5 mg/L of ZT ＋ 0.1 mg/L of GA3 ＋ 150 mg/L of cef; the optimal differentiation medium for tubers were MS＋ 0.5 mg/L of ZT ＋ 0.1 mg/L of NAA, and the tubers with diameters ranging from 0.5 to 0.7 cm had generated the most shoots. The transgenic bacteria-free plants were cultivated in propagation medium without antibiotics for 30 d with a contamination rate of 0, and the stems of bacteria-free plants were stout with no branching. [Conclusion] This method is simple and could be easily applied for the removal of bacteria, which had cleared away obstacles for the selection and growth of transgenic individuals.展开更多
Heat treatment of Ti-50.9%Ni （mole fraction） alloy was studied by differential scanning calorimetry, X-ray diffraction, scanning electron microscopey and energy dispersive X-ray analysis to investigate the influence...Heat treatment of Ti-50.9%Ni （mole fraction） alloy was studied by differential scanning calorimetry, X-ray diffraction, scanning electron microscopey and energy dispersive X-ray analysis to investigate the influence of cooling rate on transformation behavior and microstructures of NiTi shape memory alloy. The experimental results show that three-stage phase transformation can be induced at a very low cooling rate such as cooling in furnace. The cooling rate also has a great influence on the phase transformation temperatures. Both martensitic start transformation temperature （Ms） and martensitic finish transformation temperature （Mf） decrease with the decrease of the cooling rate, and decreasing the cooling rate contributes to enhancing the M→A austenite transformation temperature. The phase transformation hysteresis （Af-Mf） increases with the decrease of the cooling rate. Heat treatment is unable to eliminate the textures formed in hot working of NiTi sample, but can weaken the intensity of them. The cooling rate has little influence on the grain size.展开更多
The effect of recovery heating rate on shape memory effect of the up-quenched Cu-8.88Al-10.27Mn（mass fraction, %） alloy was investigated by optical microscopy, electron transmission microscopy（TEM） and electrical ...The effect of recovery heating rate on shape memory effect of the up-quenched Cu-8.88Al-10.27Mn（mass fraction, %） alloy was investigated by optical microscopy, electron transmission microscopy（TEM） and electrical resistivity measurement. It is found that the shape recovery rate decreases as the heating rate decreases. It can reach 75% when the heating rate is 20 ℃/min, while it is only 8% when the heating rate is 1 ℃/min. In situ microstructure observation indicates that the dependence of shape memory effect on recovery heating rate is caused by the stabilization of twinned martensite induced by deformation. The analysis of electrical resistivity shows that the stabilization of twinned martensite may be ascribed to formation of compound defects of vacancies and dislocations at the boundaries of twinned martensite during the slow heating. The compound defects prevent the reverse transformation of twinned martensite.展开更多
文摘Objective In kinesin-3,the neck coil correlates with the following segments to form an extended neck that contains a characteristic hinge diverse from a proline in KIF13B to a long flexible linker in KIF1A.The function of this neck hinge for controlling processive movement,however,remains unclear.Methods We made a series of modifications to the neck hinges of KIF13B and KIF1A and tested their movement using a single-molecule motility assay.Results In KIF13B,the insertion of flexible residues before or after the proline differentially impacts the processivity or velocity,while the removal of this proline increases the both.In KIF1A,the deletion of entire flexible neck hinge merely enhances the processivity.The engineering of these hinge-truncated necks of kinesin-3 into kinesin-1 similarly boosts the processive movement of kinesin-1.Conclusion The neck hinge in kinesin-3 controls its processive movement and proper modifications tune the motor motility,which provides a novel strategy to reshape the processive movement of kinesin motors.
基金Supported by the Key Project of Education Department of Guizhou Province "Establishment of Human Interleukin-12 Plant Expression System" (2004118)~~
文摘[Objective]The aim was to examine the anti heptocarcinoma effects of human interleukin-12（hIL-12） from transgenic potatoes.[Method]Human heptocarcinoma cell line HepG22.2.15 was cocultured with human peripherial blood monocyte（PBMC）.Human IL-12 extracted from its transgenic patatoes was introduced to this coculture system.MTT method and laser confocal microscope were then employed to evaluate its survival rates and morphological changes of HepG22.2.15 cell line.[Result]The HepG22.2.15 survival rate of the plant produced hIL-12 treated group was significantly lower than that of the wild type control,while similar to that of commercial purified recombinant hIL-12 group.As indicated by AnnexinV/PI double staining laser confocal microscope,cocultured heptocarcinoma cells showed the typical early and final phase apoptotic morphological characteristics 48 hours after 2 × 10-4 mg/L potato secreted hIL-12 treatment.[Conclusion] These results demonstrated that Heptocarcinoma HepG22.2.15 cell growth could be actively inhibited by the transgenic potato expressed hIL-12 in vitro.
基金Supported by the Project of China Geological Survey(1212010911084)~~
文摘[Objective] This study aimed to investigate the dynamic changes of vegetation cover and its prediction method. [Method] The NDVl was used as data source to perform the spatial overlay analysis on the vegetation coverage changes of the study area in different time period under the GIS platform, with the aim to reveal the spatial distribution rules of the vegetation cover in Eastern Jilin Province during the recent 10 years. The Markov Model and Grey System G （1, 1） theory model were used to predict the vegetation cover change trend in Eastern Jilin Province. [Result] The vegetation cover increased a little, but staying stable in general. The regions with great changes were mainly around the lake and river. The prediction results of Markov Model and Grey System G （1, 1） theory model were consistent with the observed measurement. [Conclusion] This study provided referential basis for the effective protection of the vegetation coverage in mountainous forest, and important reference value for the scientific decision-making on the forest construction planning in Jilin Province as well as in China and sustainable development of social economy.
基金Supported by the Open Project of National Engineering Laboratory for Tree Breeding of Beijing Forestry University~~
文摘[Objective] This research aimed to solve the problems of growth and differentiation inhibition of transgenic potato plants caused by antibiotics used for bacteriostasis. [Method] Microtubers were induced using transgenic potato plants, which had generated shoots and formed transgenic bacteria-free plants. [Result] Among the three transgenic potato varieties, the optimal induction medium for SⅠ and SⅡ were MS＋ 0.5 mg/L of 6-BA ＋ 0.1 mg/L of GA3＋ 150 mg/L of cef, and the optimal induction medium for NT were MS＋ 0.5 mg/L of ZT ＋ 0.1 mg/L of GA3 ＋ 150 mg/L of cef; the optimal differentiation medium for tubers were MS＋ 0.5 mg/L of ZT ＋ 0.1 mg/L of NAA, and the tubers with diameters ranging from 0.5 to 0.7 cm had generated the most shoots. The transgenic bacteria-free plants were cultivated in propagation medium without antibiotics for 30 d with a contamination rate of 0, and the stems of bacteria-free plants were stout with no branching. [Conclusion] This method is simple and could be easily applied for the removal of bacteria, which had cleared away obstacles for the selection and growth of transgenic individuals.
基金Project (51071056) supported by the National Natural Science Foundation of ChinaProjects (HEUCFR1132, HEUCF121712) supported by the Fundamental Research Funds for the Central Universities of China
文摘Heat treatment of Ti-50.9%Ni （mole fraction） alloy was studied by differential scanning calorimetry, X-ray diffraction, scanning electron microscopey and energy dispersive X-ray analysis to investigate the influence of cooling rate on transformation behavior and microstructures of NiTi shape memory alloy. The experimental results show that three-stage phase transformation can be induced at a very low cooling rate such as cooling in furnace. The cooling rate also has a great influence on the phase transformation temperatures. Both martensitic start transformation temperature （Ms） and martensitic finish transformation temperature （Mf） decrease with the decrease of the cooling rate, and decreasing the cooling rate contributes to enhancing the M→A austenite transformation temperature. The phase transformation hysteresis （Af-Mf） increases with the decrease of the cooling rate. Heat treatment is unable to eliminate the textures formed in hot working of NiTi sample, but can weaken the intensity of them. The cooling rate has little influence on the grain size.
文摘The effect of recovery heating rate on shape memory effect of the up-quenched Cu-8.88Al-10.27Mn（mass fraction, %） alloy was investigated by optical microscopy, electron transmission microscopy（TEM） and electrical resistivity measurement. It is found that the shape recovery rate decreases as the heating rate decreases. It can reach 75% when the heating rate is 20 ℃/min, while it is only 8% when the heating rate is 1 ℃/min. In situ microstructure observation indicates that the dependence of shape memory effect on recovery heating rate is caused by the stabilization of twinned martensite induced by deformation. The analysis of electrical resistivity shows that the stabilization of twinned martensite may be ascribed to formation of compound defects of vacancies and dislocations at the boundaries of twinned martensite during the slow heating. The compound defects prevent the reverse transformation of twinned martensite.
