Leaf-derived protoplasts of Rough lemon (Citrus jambhiri Lush, 2n = 2x = 18) were electrofused with embryogenic suspension protoplasts of its relative, Microcitrus papuana Swingle (2n = 2x = 18), with an intention of ...Leaf-derived protoplasts of Rough lemon (Citrus jambhiri Lush, 2n = 2x = 18) were electrofused with embryogenic suspension protoplasts of its relative, Microcitrus papuana Swingle (2n = 2x = 18), with an intention of creating novel germplasm. Six plants were regenerated following protoplasts fusion. Cytological examination demonstrated that they were diploids with 18 chromosomes (2n = 2x = 18). RAPD (random amplified polymorphic DNA) analyses with six arbitrary 10-mer primers showed that the regenerated plants had identical band patterns to those of Rough lemon for primers OPA-07, OPAN-07, OPE-05 and OPA-08, Whereas for the other two primers, OPA-04 and OPS-13, bands specific to M. papuana could be detected in the regenerated plants. Cytological and RAPD analysis revealed that the regenerated plants were diploid somatic hybrids between M. papuana and Rough lemon. The putative hybrids were morphologically similar to Rough lemon. This is the first report on production of diploid somatic hybrid plants between citrus with its related genus via symmetric fusion.展开更多
Protoplasts from Candida tropicalis and Candida lipolytica were fused under an optimized electrofusion （electrical pulse strength 6 kV/cm, pulse duration time 40μs and pulse times 5） and then regenerated on YEPD me...Protoplasts from Candida tropicalis and Candida lipolytica were fused under an optimized electrofusion （electrical pulse strength 6 kV/cm, pulse duration time 40μs and pulse times 5） and then regenerated on YEPD media for achieving new genotypes with higher chromium loading capacity. A target fusant RHJ-004 was screened out by its chromium resistance and chromium-sorbing capacity tests for further research. The comparative study of applicability shows that the fusant has better performance than its parent strains in respect of solution pH, biomass concentration and chromium loading capacity. Especially for treating low concentration Cr（VI） （〈20 mg/L）, above 80% chromium is sequestered from the aqueous phase at pH 1-9. Atomic force microscopy （AFM） visualizes the distribution of chromium on the binding sites of the cells, suggesting that the altered surface structure and intracellular constitutes of the fusant associate with its increased biosorption capacity. The rapid biosorption processes of chromium foUow the Langmuir model well.展开更多
The basic mechanical behaviors of high density polyethylene electrofusion welded joint at different temperatures were studied by using differently designed specimens in this paper. The results show that the strength o...The basic mechanical behaviors of high density polyethylene electrofusion welded joint at different temperatures were studied by using differently designed specimens in this paper. The results show that the strength of weld bonding plane is higher than that of the pipe and socket materials at room temperature. In order to get the shear strength of electrofusion welded joint, the effective bond lengths were reduced by cutting artificial groove through the socket. The effective bonding length of welded joint to get the shear strength is decreased with decreasing testing temperature. The shear strength and the sensibility to sharp notch of HDPE material increased with decreasing temperature.展开更多
Lipidic nanovesicles (so called liposomes) were one the earliest forms of nanovectors. One of their limits was our lack of knowledge on the delivery pathway of their content to the target cell cytoplasm. The present c...Lipidic nanovesicles (so called liposomes) were one the earliest forms of nanovectors. One of their limits was our lack of knowledge on the delivery pathway of their content to the target cell cytoplasm. The present communication describes an efficient way to enhance the delivery. Pulsed electric fields (PEF) are known since the early 80’s to mediate a fusogenic state of plasma membranes when applied to a cell suspension or a tissue. Polykaryons are detected when PEF are applied on cells in contact during or after the pulses. Heterofusion can be obtained when a cell mixture is pulsed. When lipidic nanovesicles, either small unilamellar vesicles (SUVs) or large unilamellar vesicles (LUVs), are electrostatically brought in contact with electropermeabilized cells by a salt bridge, their content is delivered into the cytoplasm in electropermeabilized cells. The PEF parameters are selected to affect specifically the cells leaving the vesicles unaffected. It is the electropermeabilized state of the cell membrane that is the trigger of the merging between the plasma membrane and the lipid bilayer. The present investigation shows that the transfer of macromolecules can be obtained;i.e. 20 kD dextrans can be easily transferred while a direct transfer does not take place under the same electrical parameters. Cell viability was not affected by the treatment. As delivery is present only on electropermeabilized cells, a targeting of the effect is obtained in the volume where the PEF parameters are over the critical value for electropermeabilization. A homogeneous cytoplasm labeling is observed under digitised videomicroscopy. The process is a content and “membrane” mixing, following neither a kiss and run or an endocytotic pathway.展开更多
The fusion strength of electrofusion joints using the polyethylene (PE) pipe connection greatly depends on the amount of sand which adheres to the interface by wind and so on, because there is no flow of melted resin ...The fusion strength of electrofusion joints using the polyethylene (PE) pipe connection greatly depends on the amount of sand which adheres to the interface by wind and so on, because there is no flow of melted resin at the fusion interface on electrofusion joints. Therefore, it is necessary to develop a method to prevent the fusion strength from reducing even in the case of sand adhesion. In this study, the fusion interface coated with polysilane, a kind of silicon polymer, effectively prevented the reduction of the fusion strength even if contaminated by sand. It was found that it brought the improvement of the fusion strength since when there was polysilane on the fusion interface. PS deeply permeated the polyethylene layer and lowered the viscosity of polyethylene.展开更多
Electrofusion between blastula cells and unfertilized eggs in loach were investigated usingdielectrophoretic field where, under alternating sinusoidal electric field, blastula cells formed beads-like chain in close co...Electrofusion between blastula cells and unfertilized eggs in loach were investigated usingdielectrophoretic field where, under alternating sinusoidal electric field, blastula cells formed beads-like chain in close contact with the unfertilized egg and cell fusion occurred between eggs and thecells in tight contact with them. The nuclei ofblastula cells were brought into the cytoplasm of therecipient eggs, where they promoted the development of the fused eggs just like the zygote nuclei.But the development of the fused eggs was different from that of zygotes. Several nuclei might enterone and the same egg simultaneously and all of them could undergo division, resulting in severalblastomere after the first cleavage of the recipient egg. Before blastula stage, the embryo developingfrom the fused egg showcd irregular shape, but it was soon regulated and developed to a normalblastula which often continued its development into a normal individual. Cell/egg electrofusion cameto its highest fosion rate (80%) 8nd hatching rate (20%), with cell density at 1×10~3 cells/ml, Ca^(++)concentration at 10 mM, mannitol at 0.2 M and when the blastula cells were digested with 100μg/ml pronase E for 6-10 min at 20℃. The mechanism underlying development of electrofused eggsis discussed. As the result indicates, electrofusion might prove to be a promising biotechnology justas nuclear transplantation.展开更多
Electrofusion of evacuolated (N. Tabacum L. cvs. Gexin no1) and vacuolated (N. Rustic) tobacco mesophyll protoplasts was performed on the Chinese spacecraft (Shenzhou No. 4, from 30th Dec. 2002 to 6th Jan. 2003). The ...Electrofusion of evacuolated (N. Tabacum L. cvs. Gexin no1) and vacuolated (N. Rustic) tobacco mesophyll protoplasts was performed on the Chinese spacecraft (Shenzhou No. 4, from 30th Dec. 2002 to 6th Jan. 2003). The results showed that the frequency of bi-nucleated and mul-tinucleated protoplasts was significantly increased under microgravity. Compared with the control samples incubated on the ground, the viability of protoplasts incubated in space was much higher. In addition, the influence of altered gravity on carbohydrates was also observed. These results confirmed the effect of microgravitation on electrofusion of plant cell protoplasts.展开更多
In fossil energy pollution is serious and the“double carbon”goal is being promoted,as a symbol of fresh energy in the electrical system,solar and wind power have an increasing installed capacity,only conventional un...In fossil energy pollution is serious and the“double carbon”goal is being promoted,as a symbol of fresh energy in the electrical system,solar and wind power have an increasing installed capacity,only conventional units obviously can not solve the new energy as the main body of the scheduling problem.To enhance the systemscheduling ability,based on the participation of thermal power units,incorporate the high energy-carrying load of electro-melting magnesiuminto the regulation object,and consider the effects on the wind unpredictability of the power.Firstly,the operating characteristics of high energy load and wind power are analyzed,and the principle of the participation of electrofusedmagnesiumhigh energy-carrying loads in the elimination of obstructedwind power is studied.Second,a two-layer optimization model is suggested,with the objective function being the largest amount of wind power consumed and the lowest possible cost of system operation.In the upper model,the high energy-carrying load regulates the blocked wind power,and in the lower model,the second-order cone approximation algorithm is used to solve the optimizationmodelwithwind power uncertainty,so that a two-layer optimizationmodel that takes into account the regulation of the high energy-carrying load of the electrofused magnesium and the uncertainty of the wind power is established.Finally,the model is solved using Gurobi,and the results of the simulation demonstrate that the suggested model may successfully lower wind abandonment,lower system operation costs,increase the accuracy of day-ahead scheduling,and lower the final product error of the thermal electricity unit.展开更多
IBRS2 epithelial cells in monolayer culture fused at a very high frequency when exposed to high-voltage electric pulsing fields. Exposure to four repetitive electric pulses of about 1.7 kilovolts per centimeter with a...IBRS2 epithelial cells in monolayer culture fused at a very high frequency when exposed to high-voltage electric pulsing fields. Exposure to four repetitive electric pulses of about 1.7 kilovolts per centimeter with a duration of 100 microseconds caused more than 90 percent of the cells to become fused (multinucleate) when 1 millimolar magnesium was present in the pulsing medium. Magnesium and calcium ions in the pulsing medium had a very strong effect on the electrofusion of IBRS2 cells. Magnesium could increase not only the electrofusion yield but also the stability of the cells under the conditions of electrofusion. In contrast, calcium inhibited electrofusion and decreased the stability of the cells. Careful microscopic observation revealed the electrofusion of IBRS2 cells to be very complex, dynamic process undergoing many interesting changes. A possible explanation for the process and mechanism of electrofusion of IBRS2 cells was proposed in agreement with the experimental observation.展开更多
The positive rate of hybridomas is low in routine McAb(monoclonal antibody)preparation because of non-selective cell fusion,thus bringing about a lot of heavy work load in screening. Meanwhile, it is not easy to obtai...The positive rate of hybridomas is low in routine McAb(monoclonal antibody)preparation because of non-selective cell fusion,thus bringing about a lot of heavy work load in screening. Meanwhile, it is not easy to obtain McAbs with high affinities to the administered antigen. These years, M.S. Lo et al. and Don M. Wojchowski et al. established two specific elec-展开更多
Protoplasts of Page tangelo (Citrus reticulata Blanco×C. paradisi Macf.) cell suspension culture were electrically fused with mesophyll protoplasts isolated from trifoliate orange (Poncirus trifoliata (L.) Raf.)....Protoplasts of Page tangelo (Citrus reticulata Blanco×C. paradisi Macf.) cell suspension culture were electrically fused with mesophyll protoplasts isolated from trifoliate orange (Poncirus trifoliata (L.) Raf.). More than 150 plantlets regenerated after 4-5 months of culture. The regenerated plants were trifoliate with well developed root systems. Root_tip chromosome counting of more than 20 randomly selected plants revealed that they were all tetraploids (2n=4x=36). RAPD analysis of 7 randomly selected plants verified their hybridity. Inoculation of citrus Phytophthora parasitica Dastar toxin on leaves of somatic hybrids and both parental genotypes showed that Page tangelo was moderately susceptible, and trifoliate orange was highly resistant while the somatic hybrids were resistant. The potential of this somatic hybrid as rootstock is also discussed.展开更多
A series of experiments were conducted to study the major procedures in nuclear transplantation such as oocyte enucleation and activation, electrofusion and developnent of the nuclear transplant embryos in the mouse, ...A series of experiments were conducted to study the major procedures in nuclear transplantation such as oocyte enucleation and activation, electrofusion and developnent of the nuclear transplant embryos in the mouse, rabbits and sheep. The important results are as follows:11. In the mouse, only 35% of the oocytes collected 15～16 h after hCG had a notable first polar body (FPb) and those without FPb were enucleated by removing cytoplasm from the PVS-wider side and the enucleation rate was similar to that in the oocytes with FPb, and the enucleation rate of removing 1/3 cytoplasm was remarkably higher than that of removing 1/4 cytoplasm. 2. Among the three fusion media tested, mannitol and sucrose solutions produced better results than M2 in electrofusion of mouse 2-cell embryos. Under favorable pulse conditions, the osmotic pressure of fusion medium had no motable effect on electrofusion, but as the conditions became so unfavorable that some embryos began to lyse, the fusion rates in hypertonie mannitol solution were significantly higher than those in isotonic or hypotonic solutions. A wide range of pulse strengths (0.31～2.04 by/ cm) and durations(10～1280 μs) were used and 100% of fusion were obtained in many cases. Optimal pulse durations were plotted for field strengths to obtain high fusion rates (96%～ 100%) in mouse2-cell embryos. 3. With one pulse of 0.45 by / cm, satisfactory results of mouse oocyte activation were obtained only when the duration increased to 160 μs or longer. The activation rate increased as the oocytes got older. Some of the oocytes ar. rested at metaphase Ⅲ after electrical stimulation and their proportion to the number of oocytes not activated increased with egg age. 4. 10% and 31% of the nuclear transplant embryos developed to morula or blastocyst stage in sheep and rabbits, respectively, with Chinese-made hormones and chemicals.展开更多
: Electrically induced protoplast fusion was used to produce somatic hybrids between Brassica napus L. and Sinapis alba L. Seven hybrids were obtained and verified by the simple sequence repeat and cleaved amplified p...: Electrically induced protoplast fusion was used to produce somatic hybrids between Brassica napus L. and Sinapis alba L. Seven hybrids were obtained and verified by the simple sequence repeat and cleaved amplified polymorphic sequence analysis of the gene fael, indicating that the characteristic bands from S. alba were present in the hybrids. The hybridity was also confirmed by chromosome number counting because the hybrids possessed 62 chromosomes, corresponding to the sum of fusion-parent chromosomes. Chromosome pairing at meiosis was predominantly normal, which led to high pollen fertility, ranging from 66% to 77%. All hybrids were grown to full maturity and could be fertilized and set seed after self-pollination or back-crosses with B. napus. The morphology of the hybrids resembled characteristics from both parental species. An analysis of the fatty acid composition in the seeds of F1 plants was conducted and the seeds were found to contain different amounts of erucic acid, ranging from 11.0% to 52.1%.展开更多
IT is well known that oocytes, in general condition, can be penetrated by sperm rather thanround spermatids. In 1993, Ogura injected round spermatid nuclei into hamster oocytes anddemonstrated that the spermatid nucle...IT is well known that oocytes, in general condition, can be penetrated by sperm rather thanround spermatids. In 1993, Ogura injected round spermatid nuclei into hamster oocytes anddemonstrated that the spermatid nuclei could transform into pronuclei with DNA synthesis andthat their chromosomes mingled with oocyte chromosomes immediately. In order to avoid themechanical damage to the oocytes, an alternative method, cell-to-cell fusion, was used. Ap-proximately 20%—40% and 30% of round spermatids could be fused with oocytes by展开更多
Mouse round spermatids were electrofused with homologous mature oocytes to examine the be-haviour of their nuclei within the ooplasm and the abilities of development. A single spermatid was injected in the perivitelli...Mouse round spermatids were electrofused with homologous mature oocytes to examine the be-haviour of their nuclei within the ooplasm and the abilities of development. A single spermatid was injected in the perivitelline space of a mature oocyte and an electron fusion pulse was given. The best round spermatid-oocyte pairs (RS-O) fusion took place at 20-30 s AC (1 MHz, 50V/cm) followed by a single fusion DC pulse (3 700-3 800 V/cm, 25 μs) and another 30 s AC current. The total survival rate and fusion rate of RS-O were 89.0% (575/646) and 61. 9% (356/575), respectively. 49.2% (175/356) of fused oocytes developed to 2PN stage . The concentration of Ca2+ in the fusion medium produced no significant effect on the above targets. The 2PN development rate of the fused RS-O from the oocytes collected 14-16 h after hCG injection was higher than others. 32.6% (57/175) of the 2PN oocytes had fully developed spermatid (male) and oocyte (female) pronuclei. The rest spermatid-derived pronu-clei remained small in size throughout the pronuclear stage. 192 fertilized eggs were transferred surgically into the oviducts of the pseudopregnant female mouse. 12 offspring were produced.展开更多
The aim of this study was to optimize electrofusion conditions for generating porcine tet- raploid （4n） embryos and produce tetraploid/diploid （4n/2n） chimeric embryos. Different electric field intensities were te...The aim of this study was to optimize electrofusion conditions for generating porcine tet- raploid （4n） embryos and produce tetraploid/diploid （4n/2n） chimeric embryos. Different electric field intensities were tested and 2 direct current （DC） pulses of 0.9 kV/em for 30 p.s was selected as the optimum condition for electrofusion of 2-cell embryos to produce 4n embryos. The fusion rate of 2-cell embryos and the development rate to blastocyst of presumably 4n embryos, reached 85.4% and 28.5%, respectively. 68.18% of the fused embryos were found to be 4n as demonstrated by fluorescent in situ hybridization （FISH）. Although the number of blastomeres in 4n blastocysts was significantly lower than in 2n blastocysts （P 〈 0.05）, there was no significant difference in developmental rates of blastocysts between 2n and 4n embryos （P 〉 0.05）, suggesting that the blas- tocyst forming capacity in 4n embryos is similar to those in 2n embryos. Moreover, 4n/2n chimeric embryos were obtained by aggregation of 4n and 2n embryos. We found that the developmental rate and cell number of blastocysts of 4-cell （4n）/4-cell （2n） chimeric embryos were significantly higher than those of 2-cell （4n）/4-cell （2n）, 4-cell （4n）/8-cell （2n）, 4-cell （4n）/2-cell （2n） chimeric embryos （P 〈 0.05）. Consistent with mouse chimeras, the majority of 4n cells contribute to the trophectoderm （TE）, while the 2n cells are mainly present in the inner cell mass （ICM） of porcine 4n/2n chimeric embryos. Our study established a feasible and efficient approach to produce porcine 4n embryos and 4n/2n chimeric embryos.展开更多
文摘Leaf-derived protoplasts of Rough lemon (Citrus jambhiri Lush, 2n = 2x = 18) were electrofused with embryogenic suspension protoplasts of its relative, Microcitrus papuana Swingle (2n = 2x = 18), with an intention of creating novel germplasm. Six plants were regenerated following protoplasts fusion. Cytological examination demonstrated that they were diploids with 18 chromosomes (2n = 2x = 18). RAPD (random amplified polymorphic DNA) analyses with six arbitrary 10-mer primers showed that the regenerated plants had identical band patterns to those of Rough lemon for primers OPA-07, OPAN-07, OPE-05 and OPA-08, Whereas for the other two primers, OPA-04 and OPS-13, bands specific to M. papuana could be detected in the regenerated plants. Cytological and RAPD analysis revealed that the regenerated plants were diploid somatic hybrids between M. papuana and Rough lemon. The putative hybrids were morphologically similar to Rough lemon. This is the first report on production of diploid somatic hybrid plants between citrus with its related genus via symmetric fusion.
基金Project(NSFC-GDNSF U0933002) supported by the Joint Funds of the National Natural Science Foundation of China and the Natural Science Foundation of Guangdong Province,ChinaProject(50978122) supported by the National Natural Science Foundation of China
文摘Protoplasts from Candida tropicalis and Candida lipolytica were fused under an optimized electrofusion （electrical pulse strength 6 kV/cm, pulse duration time 40μs and pulse times 5） and then regenerated on YEPD media for achieving new genotypes with higher chromium loading capacity. A target fusant RHJ-004 was screened out by its chromium resistance and chromium-sorbing capacity tests for further research. The comparative study of applicability shows that the fusant has better performance than its parent strains in respect of solution pH, biomass concentration and chromium loading capacity. Especially for treating low concentration Cr（VI） （〈20 mg/L）, above 80% chromium is sequestered from the aqueous phase at pH 1-9. Atomic force microscopy （AFM） visualizes the distribution of chromium on the binding sites of the cells, suggesting that the altered surface structure and intracellular constitutes of the fusant associate with its increased biosorption capacity. The rapid biosorption processes of chromium foUow the Langmuir model well.
基金This work was supported by the National Natural Science Foundation of China under grant No.50075061.
文摘The basic mechanical behaviors of high density polyethylene electrofusion welded joint at different temperatures were studied by using differently designed specimens in this paper. The results show that the strength of weld bonding plane is higher than that of the pipe and socket materials at room temperature. In order to get the shear strength of electrofusion welded joint, the effective bond lengths were reduced by cutting artificial groove through the socket. The effective bonding length of welded joint to get the shear strength is decreased with decreasing testing temperature. The shear strength and the sensibility to sharp notch of HDPE material increased with decreasing temperature.
文摘Lipidic nanovesicles (so called liposomes) were one the earliest forms of nanovectors. One of their limits was our lack of knowledge on the delivery pathway of their content to the target cell cytoplasm. The present communication describes an efficient way to enhance the delivery. Pulsed electric fields (PEF) are known since the early 80’s to mediate a fusogenic state of plasma membranes when applied to a cell suspension or a tissue. Polykaryons are detected when PEF are applied on cells in contact during or after the pulses. Heterofusion can be obtained when a cell mixture is pulsed. When lipidic nanovesicles, either small unilamellar vesicles (SUVs) or large unilamellar vesicles (LUVs), are electrostatically brought in contact with electropermeabilized cells by a salt bridge, their content is delivered into the cytoplasm in electropermeabilized cells. The PEF parameters are selected to affect specifically the cells leaving the vesicles unaffected. It is the electropermeabilized state of the cell membrane that is the trigger of the merging between the plasma membrane and the lipid bilayer. The present investigation shows that the transfer of macromolecules can be obtained;i.e. 20 kD dextrans can be easily transferred while a direct transfer does not take place under the same electrical parameters. Cell viability was not affected by the treatment. As delivery is present only on electropermeabilized cells, a targeting of the effect is obtained in the volume where the PEF parameters are over the critical value for electropermeabilization. A homogeneous cytoplasm labeling is observed under digitised videomicroscopy. The process is a content and “membrane” mixing, following neither a kiss and run or an endocytotic pathway.
文摘The fusion strength of electrofusion joints using the polyethylene (PE) pipe connection greatly depends on the amount of sand which adheres to the interface by wind and so on, because there is no flow of melted resin at the fusion interface on electrofusion joints. Therefore, it is necessary to develop a method to prevent the fusion strength from reducing even in the case of sand adhesion. In this study, the fusion interface coated with polysilane, a kind of silicon polymer, effectively prevented the reduction of the fusion strength even if contaminated by sand. It was found that it brought the improvement of the fusion strength since when there was polysilane on the fusion interface. PS deeply permeated the polyethylene layer and lowered the viscosity of polyethylene.
基金This work was supported by grants from Chinese National High-Tech.Project.
文摘Electrofusion between blastula cells and unfertilized eggs in loach were investigated usingdielectrophoretic field where, under alternating sinusoidal electric field, blastula cells formed beads-like chain in close contact with the unfertilized egg and cell fusion occurred between eggs and thecells in tight contact with them. The nuclei ofblastula cells were brought into the cytoplasm of therecipient eggs, where they promoted the development of the fused eggs just like the zygote nuclei.But the development of the fused eggs was different from that of zygotes. Several nuclei might enterone and the same egg simultaneously and all of them could undergo division, resulting in severalblastomere after the first cleavage of the recipient egg. Before blastula stage, the embryo developingfrom the fused egg showcd irregular shape, but it was soon regulated and developed to a normalblastula which often continued its development into a normal individual. Cell/egg electrofusion cameto its highest fosion rate (80%) 8nd hatching rate (20%), with cell density at 1×10~3 cells/ml, Ca^(++)concentration at 10 mM, mannitol at 0.2 M and when the blastula cells were digested with 100μg/ml pronase E for 6-10 min at 20℃. The mechanism underlying development of electrofused eggsis discussed. As the result indicates, electrofusion might prove to be a promising biotechnology justas nuclear transplantation.
文摘Electrofusion of evacuolated (N. Tabacum L. cvs. Gexin no1) and vacuolated (N. Rustic) tobacco mesophyll protoplasts was performed on the Chinese spacecraft (Shenzhou No. 4, from 30th Dec. 2002 to 6th Jan. 2003). The results showed that the frequency of bi-nucleated and mul-tinucleated protoplasts was significantly increased under microgravity. Compared with the control samples incubated on the ground, the viability of protoplasts incubated in space was much higher. In addition, the influence of altered gravity on carbohydrates was also observed. These results confirmed the effect of microgravitation on electrofusion of plant cell protoplasts.
基金funded by the National Key R&D Program of China,Grant Number 2019YFB1505400.
文摘In fossil energy pollution is serious and the“double carbon”goal is being promoted,as a symbol of fresh energy in the electrical system,solar and wind power have an increasing installed capacity,only conventional units obviously can not solve the new energy as the main body of the scheduling problem.To enhance the systemscheduling ability,based on the participation of thermal power units,incorporate the high energy-carrying load of electro-melting magnesiuminto the regulation object,and consider the effects on the wind unpredictability of the power.Firstly,the operating characteristics of high energy load and wind power are analyzed,and the principle of the participation of electrofusedmagnesiumhigh energy-carrying loads in the elimination of obstructedwind power is studied.Second,a two-layer optimization model is suggested,with the objective function being the largest amount of wind power consumed and the lowest possible cost of system operation.In the upper model,the high energy-carrying load regulates the blocked wind power,and in the lower model,the second-order cone approximation algorithm is used to solve the optimizationmodelwithwind power uncertainty,so that a two-layer optimizationmodel that takes into account the regulation of the high energy-carrying load of the electrofused magnesium and the uncertainty of the wind power is established.Finally,the model is solved using Gurobi,and the results of the simulation demonstrate that the suggested model may successfully lower wind abandonment,lower system operation costs,increase the accuracy of day-ahead scheduling,and lower the final product error of the thermal electricity unit.
文摘IBRS2 epithelial cells in monolayer culture fused at a very high frequency when exposed to high-voltage electric pulsing fields. Exposure to four repetitive electric pulses of about 1.7 kilovolts per centimeter with a duration of 100 microseconds caused more than 90 percent of the cells to become fused (multinucleate) when 1 millimolar magnesium was present in the pulsing medium. Magnesium and calcium ions in the pulsing medium had a very strong effect on the electrofusion of IBRS2 cells. Magnesium could increase not only the electrofusion yield but also the stability of the cells under the conditions of electrofusion. In contrast, calcium inhibited electrofusion and decreased the stability of the cells. Careful microscopic observation revealed the electrofusion of IBRS2 cells to be very complex, dynamic process undergoing many interesting changes. A possible explanation for the process and mechanism of electrofusion of IBRS2 cells was proposed in agreement with the experimental observation.
文摘The positive rate of hybridomas is low in routine McAb(monoclonal antibody)preparation because of non-selective cell fusion,thus bringing about a lot of heavy work load in screening. Meanwhile, it is not easy to obtain McAbs with high affinities to the administered antigen. These years, M.S. Lo et al. and Don M. Wojchowski et al. established two specific elec-
文摘Protoplasts of Page tangelo (Citrus reticulata Blanco×C. paradisi Macf.) cell suspension culture were electrically fused with mesophyll protoplasts isolated from trifoliate orange (Poncirus trifoliata (L.) Raf.). More than 150 plantlets regenerated after 4-5 months of culture. The regenerated plants were trifoliate with well developed root systems. Root_tip chromosome counting of more than 20 randomly selected plants revealed that they were all tetraploids (2n=4x=36). RAPD analysis of 7 randomly selected plants verified their hybridity. Inoculation of citrus Phytophthora parasitica Dastar toxin on leaves of somatic hybrids and both parental genotypes showed that Page tangelo was moderately susceptible, and trifoliate orange was highly resistant while the somatic hybrids were resistant. The potential of this somatic hybrid as rootstock is also discussed.
文摘A series of experiments were conducted to study the major procedures in nuclear transplantation such as oocyte enucleation and activation, electrofusion and developnent of the nuclear transplant embryos in the mouse, rabbits and sheep. The important results are as follows:11. In the mouse, only 35% of the oocytes collected 15～16 h after hCG had a notable first polar body (FPb) and those without FPb were enucleated by removing cytoplasm from the PVS-wider side and the enucleation rate was similar to that in the oocytes with FPb, and the enucleation rate of removing 1/3 cytoplasm was remarkably higher than that of removing 1/4 cytoplasm. 2. Among the three fusion media tested, mannitol and sucrose solutions produced better results than M2 in electrofusion of mouse 2-cell embryos. Under favorable pulse conditions, the osmotic pressure of fusion medium had no motable effect on electrofusion, but as the conditions became so unfavorable that some embryos began to lyse, the fusion rates in hypertonie mannitol solution were significantly higher than those in isotonic or hypotonic solutions. A wide range of pulse strengths (0.31～2.04 by/ cm) and durations(10～1280 μs) were used and 100% of fusion were obtained in many cases. Optimal pulse durations were plotted for field strengths to obtain high fusion rates (96%～ 100%) in mouse2-cell embryos. 3. With one pulse of 0.45 by / cm, satisfactory results of mouse oocyte activation were obtained only when the duration increased to 160 μs or longer. The activation rate increased as the oocytes got older. Some of the oocytes ar. rested at metaphase Ⅲ after electrical stimulation and their proportion to the number of oocytes not activated increased with egg age. 4. 10% and 31% of the nuclear transplant embryos developed to morula or blastocyst stage in sheep and rabbits, respectively, with Chinese-made hormones and chemicals.
文摘: Electrically induced protoplast fusion was used to produce somatic hybrids between Brassica napus L. and Sinapis alba L. Seven hybrids were obtained and verified by the simple sequence repeat and cleaved amplified polymorphic sequence analysis of the gene fael, indicating that the characteristic bands from S. alba were present in the hybrids. The hybridity was also confirmed by chromosome number counting because the hybrids possessed 62 chromosomes, corresponding to the sum of fusion-parent chromosomes. Chromosome pairing at meiosis was predominantly normal, which led to high pollen fertility, ranging from 66% to 77%. All hybrids were grown to full maturity and could be fertilized and set seed after self-pollination or back-crosses with B. napus. The morphology of the hybrids resembled characteristics from both parental species. An analysis of the fatty acid composition in the seeds of F1 plants was conducted and the seeds were found to contain different amounts of erucic acid, ranging from 11.0% to 52.1%.
文摘IT is well known that oocytes, in general condition, can be penetrated by sperm rather thanround spermatids. In 1993, Ogura injected round spermatid nuclei into hamster oocytes anddemonstrated that the spermatid nuclei could transform into pronuclei with DNA synthesis andthat their chromosomes mingled with oocyte chromosomes immediately. In order to avoid themechanical damage to the oocytes, an alternative method, cell-to-cell fusion, was used. Ap-proximately 20%—40% and 30% of round spermatids could be fused with oocytes by
基金Project supported by the State Key Laboratory of Reproductive Biology.
文摘Mouse round spermatids were electrofused with homologous mature oocytes to examine the be-haviour of their nuclei within the ooplasm and the abilities of development. A single spermatid was injected in the perivitelline space of a mature oocyte and an electron fusion pulse was given. The best round spermatid-oocyte pairs (RS-O) fusion took place at 20-30 s AC (1 MHz, 50V/cm) followed by a single fusion DC pulse (3 700-3 800 V/cm, 25 μs) and another 30 s AC current. The total survival rate and fusion rate of RS-O were 89.0% (575/646) and 61. 9% (356/575), respectively. 49.2% (175/356) of fused oocytes developed to 2PN stage . The concentration of Ca2+ in the fusion medium produced no significant effect on the above targets. The 2PN development rate of the fused RS-O from the oocytes collected 14-16 h after hCG injection was higher than others. 32.6% (57/175) of the 2PN oocytes had fully developed spermatid (male) and oocyte (female) pronuclei. The rest spermatid-derived pronu-clei remained small in size throughout the pronuclear stage. 192 fertilized eggs were transferred surgically into the oviducts of the pseudopregnant female mouse. 12 offspring were produced.
基金supported by grants from the National Basic Research Program of China(973 ProgramGrant No.2009CB941000 and 2011CB944202)the Fund for Outstanding Young Scholars in Heilongjiang Province(Grant No.JC200905)
文摘The aim of this study was to optimize electrofusion conditions for generating porcine tet- raploid （4n） embryos and produce tetraploid/diploid （4n/2n） chimeric embryos. Different electric field intensities were tested and 2 direct current （DC） pulses of 0.9 kV/em for 30 p.s was selected as the optimum condition for electrofusion of 2-cell embryos to produce 4n embryos. The fusion rate of 2-cell embryos and the development rate to blastocyst of presumably 4n embryos, reached 85.4% and 28.5%, respectively. 68.18% of the fused embryos were found to be 4n as demonstrated by fluorescent in situ hybridization （FISH）. Although the number of blastomeres in 4n blastocysts was significantly lower than in 2n blastocysts （P 〈 0.05）, there was no significant difference in developmental rates of blastocysts between 2n and 4n embryos （P 〉 0.05）, suggesting that the blas- tocyst forming capacity in 4n embryos is similar to those in 2n embryos. Moreover, 4n/2n chimeric embryos were obtained by aggregation of 4n and 2n embryos. We found that the developmental rate and cell number of blastocysts of 4-cell （4n）/4-cell （2n） chimeric embryos were significantly higher than those of 2-cell （4n）/4-cell （2n）, 4-cell （4n）/8-cell （2n）, 4-cell （4n）/2-cell （2n） chimeric embryos （P 〈 0.05）. Consistent with mouse chimeras, the majority of 4n cells contribute to the trophectoderm （TE）, while the 2n cells are mainly present in the inner cell mass （ICM） of porcine 4n/2n chimeric embryos. Our study established a feasible and efficient approach to produce porcine 4n embryos and 4n/2n chimeric embryos.
