Objective： To study the effect of ciglitazone on hepatic cancer cells HepG2 growth in vitro and in vivo and its mechanisms. Methods： The in vitro cultured HepG2 lines were treated with various concentrations of cigl...Objective： To study the effect of ciglitazone on hepatic cancer cells HepG2 growth in vitro and in vivo and its mechanisms. Methods： The in vitro cultured HepG2 lines were treated with various concentrations of ciglitazone. The in vitro growth of HepG2 cells was examined by growth curve and the cell cycle was analyzed by flow cytometry. HepG2 cells （1×10^6 /mouse） were inoculated subcutaneously into 20 nude mice to establish the hepatocellular carcinoma model. The mice were randomly divided into two groups： the control group （group A, n=10） and the ciglitazone-treated group （group B, n=10）. The mice in the group B were injected with 100μL （100μmol/L） of ciglitazone every other day for 15 times, while the mice in the group A with saline instead. One month later, the weights of the resected subcutaneous tumors and suppression rates were measured. The expression of cyclinD1 and P21 was detected by Western blot. Results： The proliferation of HepG2 was significantly inhibited by ciglitazone in a dose- and timedependant manner. There were more cells arrested in G1/G0 phase and the expression of PPARγ was markedly up-regulated in HepG2 cells treated with ciglitazone. After the treatment with ciglitazone, the average weights of the tumors in the group A and B were 3.73±0.22 g and 2.60±0.35 g, respectively, and the tumor suppression rate in the group B was 30%. The expression of cyclinD1 was increased significantly, while that of P21 was decreased significantly in group A as compared with that in group B. Conclusion： Ciglitazone could significantly inhibit HepG2 proliferation in a dose- and time-dependent manner, and induce differentiation of HepG2, the mechanism of which may be related to the PPARγ intervention to cell cycle control.展开更多
The aim of this work is to study the effects of the electret property of natural biopolymers (such as collagen) on tissue repair. Type I collagen was prepared from pigskin,and polarized by using the TSDC (thermally st...The aim of this work is to study the effects of the electret property of natural biopolymers (such as collagen) on tissue repair. Type I collagen was prepared from pigskin,and polarized by using the TSDC (thermally stimulated depolarization current) technique. The polarized materials are used for cell culture. and then the cell growth curve is drawn. It was found that the polarized biomaterials accelerated cell differentiation. which indicates that they may be applied in the biomedical field.展开更多
Strategies to fill the huge gap in supply versus demand of human organs include bioartificial organs, growing humanized organs in animals, cell therapy, and implantable bioengineered constructs. Reproducing the comple...Strategies to fill the huge gap in supply versus demand of human organs include bioartificial organs, growing humanized organs in animals, cell therapy, and implantable bioengineered constructs. Reproducing the complex relations between different cell types, generation of adequate vasculature, and immunological complications are road blocks in generation of bioengineered organs, while immunological complications limit the use of humanized organs produced in animals. Recent developments in induced pluripotent stem cell (iPSC) biology offer a possibility of generating human, patient-specific organs in non-human primates (NHP) using patient-derived iPSC and NHP-derived iPSC lacking the critical developmental genes for the organ of interest complementing a NHP tetraploid embryo. The organ derived in this way will have the same human leukocyte antigen (HLA) profile as the patient. This approach can be curative in genetic disorders as this offers the possibility of gene manipulation and correction of the patient's genome at the iPSC stage before tetraploid complementation. The process of generation of patient-specific organs such as the liver in this way has the great advantage of making use of the natural signaling cascades in the natural milieu probably resulting in organs of great quality for transplantation. However, the inexorable scientific developments in this direction involve several social issues and hence we need to educate and prepare society in advance to accept the revolutionary consequences, good, bad and ugly.展开更多
Endophytes are beneficial microbes that are capable of promoting growth, besides protecting colonized plants against plant pathogens. These microbes are of either bacterial, fungal or actinomycetes in plants. In the s...Endophytes are beneficial microbes that are capable of promoting growth, besides protecting colonized plants against plant pathogens. These microbes are of either bacterial, fungal or actinomycetes in plants. In the study, the endophytic bacteria isolated from sugarcane with their characterization related to plant growth promotion and pathogen suppression have been reported. Roots, shoots and leaves of rooted tissue culture plantlets of sugarcane cultivars of 87A298 and 2009A107 were excised aseptically and isolated endophytic bacterial strains. The strains were identified using 16S rRNA gene sequence based homology. Molecular characterization of these strains was carried out for presence of antimicrobial genes. The results showed that the endophytes isolated from sugarcane tissue culture plantlets were of the genera Bacillus （B. amyloliquefaciens, B. subtilis, B. cereus, B. safensis, B. siamensis, B. aryabhattai, B. flexus and B. velezensis） and Paenibacillus pabuli. There were three antimicrobial peptides （AMPs） producing genes of bacilysin, bacillomycin and fengycin in B. amyloliquefaciens （SE1, SE7）, B. siamensis （SE4, SE16）, B. subtilis （SE2, SE3） and B. velezensis （SE15）. The biochemical characterization assays showed that some of these strains could produce hydrogen cyanide （HCN）, protease, cellulase and indole acetic acid （IAA）. Few strains （SE1 and SE4） were phosphate solubilizers, whereas nine isolates were found to be diazotrophs. Most of the bacterial isolates were found antagonistic to Fusarium sacchari, the sugarcane wilt pathogen under in vitro conditions. Overall, the results suggested the scope and potentiality of sugarcane endophytic bacteria, isolated from tissue culture plantlets, in promoting plant growth and suppression of sugarcane pathogen.展开更多
It is hypothesized that steady anguilliform swimming motion of aquatic animals is purely reactive such that no net vortex wake is left downstream. This is versus carangiform and tunniform swimming of fish, where vorte...It is hypothesized that steady anguilliform swimming motion of aquatic animals is purely reactive such that no net vortex wake is left downstream. This is versus carangiform and tunniform swimming of fish, where vortex streams are shed from tail, fins, and body. But there the animal movements are such to produce partial vortex cancellation downstream in maximizing propulsive efficiency. In anguilliform swimming characteristic of the eel family, it is argued that the swimming motions are configured by the animal such that vortex shedding does not occur at all. However, the propulsive thrust in this case is higher order in the motion amplitude, so that relatively large coils are needed to produce relatively small thrust; the speeds of anguilliform swimmers are less than the carangiform and tunniforrn, which develop first order thrusts via lifting processes. Results of experimentation on live lamprey are compared to theoretical prediction which assumes the no-wake hypothesis. Two-dimensional analysis is first performed to set the concept. This is followed by three-dimensional analysis using slender-body theory. Slender-body theory has been applied by others in studying anguilliform swimming, as it is ideally suited to the geometry of the lamprey and other eel-like animals. The agreement between this new approach based on the hypothesis of wakeless swimming and the experiments is remarkably good in spite of the physical complexities.展开更多
In this paper, we perform a numerical simulation of the cavitating flow around an underwater hemispherical-head slender body running at a high speed. For the first time, the slip boundary condition is introduced into ...In this paper, we perform a numerical simulation of the cavitating flow around an underwater hemispherical-head slender body running at a high speed. For the first time, the slip boundary condition is introduced into this problem, and we find that the slip boundary condition has a big influence on the cavitation in the flow-separation zone. By simulating the cavitating flow under different cavitation numbers, we demonstrate that the slip boundary condition can effectively reduce the intensity of cavitation, as represented by the length of cavitation bubbles. The present paper provides a new method for utilization of new surface materials to control the cavitation on the underwater moving objects.展开更多
Dear Editor,The nitrogen-fixing symbiotic bacteria, rhizobia are the most important beneficial bacteria in soil, as they form nodules with host legume plants to fix nitrogen to maintain soil fertility and facilitate p...Dear Editor,The nitrogen-fixing symbiotic bacteria, rhizobia are the most important beneficial bacteria in soil, as they form nodules with host legume plants to fix nitrogen to maintain soil fertility and facilitate plant growth. Although these bacteria are critically important to agriculture, bacteriophages of rhizobia (rhizobiophages) are commonly present in soils, rhizosphere,and nodules, which have major influences on the composition and population of rhizobia in soils and affect nodulation and nitrogen fixation. Despite the importance of rhizobiophages,only 23 phage full genomes have been sequenced.展开更多
文摘Objective： To study the effect of ciglitazone on hepatic cancer cells HepG2 growth in vitro and in vivo and its mechanisms. Methods： The in vitro cultured HepG2 lines were treated with various concentrations of ciglitazone. The in vitro growth of HepG2 cells was examined by growth curve and the cell cycle was analyzed by flow cytometry. HepG2 cells （1×10^6 /mouse） were inoculated subcutaneously into 20 nude mice to establish the hepatocellular carcinoma model. The mice were randomly divided into two groups： the control group （group A, n=10） and the ciglitazone-treated group （group B, n=10）. The mice in the group B were injected with 100μL （100μmol/L） of ciglitazone every other day for 15 times, while the mice in the group A with saline instead. One month later, the weights of the resected subcutaneous tumors and suppression rates were measured. The expression of cyclinD1 and P21 was detected by Western blot. Results： The proliferation of HepG2 was significantly inhibited by ciglitazone in a dose- and timedependant manner. There were more cells arrested in G1/G0 phase and the expression of PPARγ was markedly up-regulated in HepG2 cells treated with ciglitazone. After the treatment with ciglitazone, the average weights of the tumors in the group A and B were 3.73±0.22 g and 2.60±0.35 g, respectively, and the tumor suppression rate in the group B was 30%. The expression of cyclinD1 was increased significantly, while that of P21 was decreased significantly in group A as compared with that in group B. Conclusion： Ciglitazone could significantly inhibit HepG2 proliferation in a dose- and time-dependent manner, and induce differentiation of HepG2, the mechanism of which may be related to the PPARγ intervention to cell cycle control.
文摘The aim of this work is to study the effects of the electret property of natural biopolymers (such as collagen) on tissue repair. Type I collagen was prepared from pigskin,and polarized by using the TSDC (thermally stimulated depolarization current) technique. The polarized materials are used for cell culture. and then the cell growth curve is drawn. It was found that the polarized biomaterials accelerated cell differentiation. which indicates that they may be applied in the biomedical field.
文摘Strategies to fill the huge gap in supply versus demand of human organs include bioartificial organs, growing humanized organs in animals, cell therapy, and implantable bioengineered constructs. Reproducing the complex relations between different cell types, generation of adequate vasculature, and immunological complications are road blocks in generation of bioengineered organs, while immunological complications limit the use of humanized organs produced in animals. Recent developments in induced pluripotent stem cell (iPSC) biology offer a possibility of generating human, patient-specific organs in non-human primates (NHP) using patient-derived iPSC and NHP-derived iPSC lacking the critical developmental genes for the organ of interest complementing a NHP tetraploid embryo. The organ derived in this way will have the same human leukocyte antigen (HLA) profile as the patient. This approach can be curative in genetic disorders as this offers the possibility of gene manipulation and correction of the patient's genome at the iPSC stage before tetraploid complementation. The process of generation of patient-specific organs such as the liver in this way has the great advantage of making use of the natural signaling cascades in the natural milieu probably resulting in organs of great quality for transplantation. However, the inexorable scientific developments in this direction involve several social issues and hence we need to educate and prepare society in advance to accept the revolutionary consequences, good, bad and ugly.
文摘Endophytes are beneficial microbes that are capable of promoting growth, besides protecting colonized plants against plant pathogens. These microbes are of either bacterial, fungal or actinomycetes in plants. In the study, the endophytic bacteria isolated from sugarcane with their characterization related to plant growth promotion and pathogen suppression have been reported. Roots, shoots and leaves of rooted tissue culture plantlets of sugarcane cultivars of 87A298 and 2009A107 were excised aseptically and isolated endophytic bacterial strains. The strains were identified using 16S rRNA gene sequence based homology. Molecular characterization of these strains was carried out for presence of antimicrobial genes. The results showed that the endophytes isolated from sugarcane tissue culture plantlets were of the genera Bacillus （B. amyloliquefaciens, B. subtilis, B. cereus, B. safensis, B. siamensis, B. aryabhattai, B. flexus and B. velezensis） and Paenibacillus pabuli. There were three antimicrobial peptides （AMPs） producing genes of bacilysin, bacillomycin and fengycin in B. amyloliquefaciens （SE1, SE7）, B. siamensis （SE4, SE16）, B. subtilis （SE2, SE3） and B. velezensis （SE15）. The biochemical characterization assays showed that some of these strains could produce hydrogen cyanide （HCN）, protease, cellulase and indole acetic acid （IAA）. Few strains （SE1 and SE4） were phosphate solubilizers, whereas nine isolates were found to be diazotrophs. Most of the bacterial isolates were found antagonistic to Fusarium sacchari, the sugarcane wilt pathogen under in vitro conditions. Overall, the results suggested the scope and potentiality of sugarcane endophytic bacteria, isolated from tissue culture plantlets, in promoting plant growth and suppression of sugarcane pathogen.
文摘It is hypothesized that steady anguilliform swimming motion of aquatic animals is purely reactive such that no net vortex wake is left downstream. This is versus carangiform and tunniform swimming of fish, where vortex streams are shed from tail, fins, and body. But there the animal movements are such to produce partial vortex cancellation downstream in maximizing propulsive efficiency. In anguilliform swimming characteristic of the eel family, it is argued that the swimming motions are configured by the animal such that vortex shedding does not occur at all. However, the propulsive thrust in this case is higher order in the motion amplitude, so that relatively large coils are needed to produce relatively small thrust; the speeds of anguilliform swimmers are less than the carangiform and tunniforrn, which develop first order thrusts via lifting processes. Results of experimentation on live lamprey are compared to theoretical prediction which assumes the no-wake hypothesis. Two-dimensional analysis is first performed to set the concept. This is followed by three-dimensional analysis using slender-body theory. Slender-body theory has been applied by others in studying anguilliform swimming, as it is ideally suited to the geometry of the lamprey and other eel-like animals. The agreement between this new approach based on the hypothesis of wakeless swimming and the experiments is remarkably good in spite of the physical complexities.
基金the National Natural Science Foundation of China(Grant No.11172001)
文摘In this paper, we perform a numerical simulation of the cavitating flow around an underwater hemispherical-head slender body running at a high speed. For the first time, the slip boundary condition is introduced into this problem, and we find that the slip boundary condition has a big influence on the cavitation in the flow-separation zone. By simulating the cavitating flow under different cavitation numbers, we demonstrate that the slip boundary condition can effectively reduce the intensity of cavitation, as represented by the length of cavitation bubbles. The present paper provides a new method for utilization of new surface materials to control the cavitation on the underwater moving objects.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences (XDB15010103)National Natural Science Foundation of China (41301259, 41671251)Youth Innovation Promotion Association CAS
文摘Dear Editor,The nitrogen-fixing symbiotic bacteria, rhizobia are the most important beneficial bacteria in soil, as they form nodules with host legume plants to fix nitrogen to maintain soil fertility and facilitate plant growth. Although these bacteria are critically important to agriculture, bacteriophages of rhizobia (rhizobiophages) are commonly present in soils, rhizosphere,and nodules, which have major influences on the composition and population of rhizobia in soils and affect nodulation and nitrogen fixation. Despite the importance of rhizobiophages,only 23 phage full genomes have been sequenced.
