Alcohol consumption causes cellular injury. Recent developments indicate that ethanol induces epigenetic alterations, particularly acetylation, methylation of histones, and hypo- and hypermethylation of DNA. This has ...Alcohol consumption causes cellular injury. Recent developments indicate that ethanol induces epigenetic alterations, particularly acetylation, methylation of histones, and hypo- and hypermethylation of DNA. This has opened up a new area of interest in ethanol research and is providing novel insight into actions of ethanol at the nucleosomal level in relation to gene expression and patho-physiological consequences. The epigenetic effects are mainly attributable to ethanol metabolic stress (Emess), generated by the oxidative and non-oxidative metabolism of ethanol, and dysregulation of methionine metabolism. Epigenetic changes are important in ethanol-induced hepatic steatosis, fibrosis, carcinoma and gastrointestinal injury. This editorial highlights these new advances and its future potential.展开更多
Over the past few years, evidence has accumulated indicating that apart from genetic alterations, epigenetic alterations, through e.g. aberrant promoter methylation, play a major role in the initiation and progression...Over the past few years, evidence has accumulated indicating that apart from genetic alterations, epigenetic alterations, through e.g. aberrant promoter methylation, play a major role in the initiation and progression of colorectal cancer (CRC). Even in the hereditary colon cancer syndromes, in which the susceptibility is inherited dominantly, cancer develops only as the result of the progressive accumulation of genetic and epigenetic alterations. Diet can both prevent and induce colon carcinogenesis, for instance, through epigenetic changes, which regulate the homeostasis of the intestinal mucosa. Food-derived compounds are constantly present in the intestine and may shift cellular balance toward harmful outcomes, such as increased susceptibility to mutations. There is strong evidence that a major component of cancer risk may involve epigenetic changes in normal cells that increase the probability of cancer after genetic mutation. The recognition of epigenetic changes as a driving force in colorectal neoplasia would open new areas of research in disease epidemiology, risk assessment, and treatment, especially in mutation carriers who already have an inherited predisposition to cancer.展开更多
AIM: To observe the therapeutic effect of intrasplenic transplantation with embryonic hepatocytes on amelioration of hereditary copper accumulation in toxic milk (TX) mouse modeling Wilson disease. METHODS: Donor hepa...AIM: To observe the therapeutic effect of intrasplenic transplantation with embryonic hepatocytes on amelioration of hereditary copper accumulation in toxic milk (TX) mouse modeling Wilson disease. METHODS: Donor hepatocytes were harvested from 14-d fetal liver of a pregnant homogeneous DL mouse. These cells were successively cultured, labeled with fluorescein dye Hoechst 33342 for 24 h, and sequentially infused into the spleen parenchyma of the recipient TX mice. No host immunosuppression measures were taken. Two and four weeks after transplantation, the recipients were killed for routine histologic investigation and immunohistochemistry study up to 4 wk after transplantation. The serum copper and ceruloplasmin concentrations of the recipient mice were determined by graphite furnace atomic absorption spectroscopy.RESULTS: In the following 2nd and 4th wk after transplantation, the donor hepatocytes could be visualized in the livers of 47.3% recipients. The serum ceruloplasmin and copper concentrations increased by 1.6-fold after 2 wk and 2.0-fold times after 4 wk respectively, which ultimately rose from about 30% of the normal level to nearly 60%(P<0.01). The hepatic copper concentration decreased 7.2%, 4 wk after transplantation. Pathologic examination showed that there were many actively proliferative hepatocyte precursor cells with specific embryonic hepatocyte marker AFP migrated into hepatic sinusoidsof the recipients. A large number of cells carrying hepatocytes marker and albumin were observed in the recipient spleen tissues.CONCLUSION: Embryonic hepatocytes are capable of differentiating into mature hepatocytes in vivo. After transplantation, the hereditary abnormalities of copper metabolism in TX mice could be corrected partially by intrasplenic transplantation of homogeneous embryonic hepatocytes.展开更多
As a part of a basic research project on Xeno-transplantion. we have been engaged in the derivation of embryonic stein cell lines from Chinese mini swine. Here, we reported for the first time the establishment of two ...As a part of a basic research project on Xeno-transplantion. we have been engaged in the derivation of embryonic stein cell lines from Chinese mini swine. Here, we reported for the first time the establishment of two porcine EG cell lines (BPEG1 and BPEG2) from primordial germ cells of genital ridges of a 28 and a 27 d embryos respectively. Their pluripotent nature has been identified by colony morphology, marker characterization as well as by in vitro and in vivo differentiation. These porcine EG cells are potentially useful for further basic studies.展开更多
Hsp90 is a specialized molecular chaperone that is capable of buffering the expression of abnormal phenotypes. Inhibition of Hsp90 activity results in the expression of these phenotypes that are otherwise masked. Sele...Hsp90 is a specialized molecular chaperone that is capable of buffering the expression of abnormal phenotypes. Inhibition of Hsp90 activity results in the expression of these phenotypes that are otherwise masked. Selection of offspring from the crossing of affected progenies results in inheritance and enrichment of these phenotypes, which can become independent of their original stimuli. The current combined evidence favours a model involving the interplay between genetics and epigenetics. The recent proteomics efforts to characterize the Hsp90 interaction networks provide further clues into the molecular mechanisms behind this complex phenomenon. This review summarizes the most recent experimental observations and briefly discusses the genetic and epigenetic views used in explaining the different observations.展开更多
Objective: To investigate the relation between Shp-2 (a cytoplasmic tyrosine phosphotase) and matrix metalloproteinase-1 (MMP-1) in the migration of mouse embryo fibroblast cell. Methods: Shp-2 -/-embryo fibroblast wa...Objective: To investigate the relation between Shp-2 (a cytoplasmic tyrosine phosphotase) and matrix metalloproteinase-1 (MMP-1) in the migration of mouse embryo fibroblast cell. Methods: Shp-2 -/-embryo fibroblast was separated from Shp-2 knockout mouse on E10. 5, and Shp-2 cDNA was transfected into Shp-2 -/- cell. The cell migration was observed with the wound healing, the MMP-1 expression and secretion was analyzed by immunoblotting and immunoprecipitation. The activation of MMP-1 in the supernatant was detected with type I collagenase activity assay after the stimulation of IL-1α compared with E10. 5 mouse embryo fibroblast cell(Shp-2 +/+). Results: There was obvious migration in Shp-2 +/+ cells and Shp-2 -/-R cells, but not in Shp-2 -/- cells. The shape of Shp-2 -/- cell was epithelial-like. The expression and secretion was increased in Shp-2 +/+ cells and Shp-2 -/-R cells, and it had not changed in Shp-2 -/- cell. The activation of MMP-1 was lower in Shp-2 -/- cells compared to the other cells. Conclusion: IL-1 induces the expression and secretion of MMP-1α at the physical dose, and the cell migration is involved in MMP-1 by way of Shp-2 signal transduction.展开更多
The developmental process of Myeloma cells under a digital optical microscope has been inspected and monitored by using time-lapsed recording technique. Myeloma cells were cultured in medium contained 20% and 50% of F...The developmental process of Myeloma cells under a digital optical microscope has been inspected and monitored by using time-lapsed recording technique. Myeloma cells were cultured in medium contained 20% and 50% of Fetal Bovine Serum (FBS), respectively. Inspection and monitoring for 6 hours showed the effect of the FBS to mobility, proliferation rate, and development of cell cycle phases of Myeloma cells. Using time-lapsed data, the speed of cells was 3.5-6.0 pm/s when using FBS 20% and increased to 5.0-8.0 p.m/s when using FBS 50%. The rate of cells decreases from 2 cells/hr when using FBS 20% to 1/6 cells/br when using FBS 50%. The cells division process is signified by the change in gray level and it took every 50-70 minutes.展开更多
Combining with Jeffery :quation and mechanics model of fixed point of Euler rigid btdy, the mechanism and method of short fiber radial orientrion and characteristics of movement in tread extrusion process were studie...Combining with Jeffery :quation and mechanics model of fixed point of Euler rigid btdy, the mechanism and method of short fiber radial orientrion and characteristics of movement in tread extrusion process were studied. The influences of tension flow field and shear flow field in flow channel on short fiber orientation trove been systemically analyzed. The extrusion die, which had a hinder dam by adopting such principle, was designed. The results show that the expansion ratio and expanding angle of cross section are the key factors to determine the radial orientation of short fiber. Mathematical model of short fiber radial orientation was established. The results also show that the best expansion ratio is 3 - 4, the expanding angle is 75°, obtaining the average orientation angle between 70°- 80°, and the rationality of the radial oriented mechanism and the mathematical model are verified.展开更多
We have examined the myogenic potential of human embryonic stem (hES) cells in a xeno-transplantation animal model. Here we show that precursors differentiated from hES cells can undergo myogenesis in an adult envir...We have examined the myogenic potential of human embryonic stem (hES) cells in a xeno-transplantation animal model. Here we show that precursors differentiated from hES cells can undergo myogenesis in an adult environment and give rise to a range of cell types in the myogenic lineage. This study provides direct evidences that hES cells can regenerate both muscle and satellite cells in vivo and are another promising cell type for treating muscle degenerative disorders in addition to other myogenic cell types.展开更多
Validating a method of analysis goes through different steps, which aims at testing the normality of measurements distribution, estimating the uncertainty of the components of a measurement (i.e., accuracy and correc...Validating a method of analysis goes through different steps, which aims at testing the normality of measurements distribution, estimating the uncertainty of the components of a measurement (i.e., accuracy and correctness), and finally, define the control tests of non degradation of the method performances. This paper outlines the steps for validating a biological method of analysis. It involves the construction of an experimental design, a statistical model, and the preparation of an interne laboratory reference material (pilot vaccine). The latter is used to study the impact of deviation and variation factors, in order to, optimize the analytical method, to evaluate the bias (random error), and to calculate the uncertainty of measurement, and make the control charts. This method is applied in the titration of live viral vaccines of Gumboro disease on chicken's embryos fibroblasts. The experimental results show that potential influence factors related to the titration method had no significant influence on the obtained results. Taking into account these results, an operating mode has been elaborated. The finalized method proved to be faithful to standard deviation of repeatability and reproducibility of 0.21 and 0.22, respectively, with a confidence level of 95%. The calculated uncertainty of measurement is equal to 0.2, which represents the average error level of a titer. A homogeneous stock of interne laboratory reference vaccine (MRIL), with an average titer of 5.9 log DIT 50, was produced and the control chart set in away to provide the laboratory with an important tool of control and monitoring of the viral titers evolution in time, as well as, the mastery of the validated titration method performances.展开更多
Anxiety is one of the psychological problems in pregnant women that sometimes takes the form of pathological and affects the mental health of mother. The aim of this study was to determine the effects of fetal movemen...Anxiety is one of the psychological problems in pregnant women that sometimes takes the form of pathological and affects the mental health of mother. The aim of this study was to determine the effects of fetal movement counting on mental health of mother. In a randomized-controlled trial, 208 nulliparous women were randomly divided into two groups. At 28th weeks, both groups completed the GHQ-28. Then the intervention group started to count fetal movements from 28th to 37th weeks of gestation and the control group received routine prenatal care. Again, both groups completed the questionnaire at 37 weeks' gestation and the results were compared. Analysis was performed by SPSS and a P value 〈 0.05 was considered significant. The mean scores of mental health of mothers in 28th and 37th of pregnancy was respectively 23.52 ± 10.23 and 21.09 ± 10.12 in the intervention group and the difference was significant (P = 0.025). The mean in the control group was 23.69 ± 9.43 and 23.88± 8.60 respectively, and the difference was not significant (P = 0.52). In comparing the mean scores between the two groups, it was found that the difference was not significant at 28th weeks of gestation (P = 0.37), but it was significant in 37th week (P = 0.002) and the counting of fetal movements could improve the mental health of mothers compared to control group. The women who had fetal movements counting at weeks 28 to 37 Of gestation reported better mental health than the control group. The mother renorted concerns about decreased fetal movement was similar in the two grouns.展开更多
This paper describes the embryonic development of the common cutworm Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) which is divided into eight embryonic stages, through variations in the egg's contents....This paper describes the embryonic development of the common cutworm Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) which is divided into eight embryonic stages, through variations in the egg's contents. Experiments were conducted on the eggs ofS. litura under laboratory conditions. The highest concentration of the protein (min.-max.: 32-! 40 lag/egg) and the lowest of the carbohydrate (min.-max.: 3.0-44.0 lag/egg) were obtained; similarly, the DNA content was smaller (min.-max.: 1.0-38.2 lag/egg) than the RNA (min.-max.: 9.2-360.0 lag/egg) throughout the embryogenesis. Three peaks of ecdysteroid titre were observed which were responsible for appearance of particular events during embryogenesis. The last highest peak of 400_+33.4 lag/egg was appeared at 84 h after oviposition when larva was ready to hatch. Therefore, it is concluded that eight embryonic stages in S. litura were characterized by fluctuation in the egg's contents, which were responsible for gradual-progressive embryonic development. The egg-larval development did not show a normal distribution of embryonic developmental-time.展开更多
This paper expounds on the tendency of energy supervision reform with consideration to the general background of energy reform. It proposes the following aspects. First, the focus of energy supervision should shift to...This paper expounds on the tendency of energy supervision reform with consideration to the general background of energy reform. It proposes the following aspects. First, the focus of energy supervision should shift to in-process and post supervision after cancellation or decentralization of energy project approval, Hence, the supervision over construction and completion acceptance is reinforced. Second, with the progression of marketoriented reforms in tire electricity and petroleum sectors, relevant energy authorities should strengthen supervision on key aspects in the electricity and petroleum sectors, particularly by way of specific supervision and problem supervision, in order to keep tire market fair, open and transparent. Third, innovative supervision modes should be adopted to improve supervision performance, so as to realize effective supervision amt finally achieve standardized and normalized energy supervision. These proposals rtTresent both the challenges and tasks that the supervision authorities face but also highlight important chances to realize the energy supervision revolution. Energy enterprises should continuously update thenzselves on the reforms and actions of energy supervision in order to meet the compliance requirements of construction and operation.展开更多
The research considered urgent ecological reasons linked to environment such as worn tires, the waste tire rubber's powder was collected from the tire cars repair shops (passed from the sieve No 18 μm), and used t...The research considered urgent ecological reasons linked to environment such as worn tires, the waste tire rubber's powder was collected from the tire cars repair shops (passed from the sieve No 18 μm), and used to improve the asphalt concrete properties. Raw materials used were prepared and tested. Varies of asphalt concrete mixtures were prepared with different ratios of bitumen (5, 5.5, 6, 6.5, 7% % of concrete weight). The Marshall mix design method was used to determine optimum conditions for bitumen in asphalt concrete with specific weight, stability and flow Test, the optimum amount of bitumen was 6.1% of whole asphalt concrete. The different percentages of waste tire rubber powder (0.0, 0.05, 0.10, 0.15% of bitumen weight) were added in optimum bitumen of asphalt concretes, then specific weight and Marshall test were evaluated. These asphalt-rubber mixtures were found to act quite differently from traditional, unmodified asphalt mixtures. However, these results indicate that improved pavement performance can be achieved with asphalt-rubber binder.展开更多
This research was carried out in the area of experimental embryology, which covers from animal fertilization to cloning. Two achievements in the field of reproductive bilogy have created major influence in the past 50...This research was carried out in the area of experimental embryology, which covers from animal fertilization to cloning. Two achievements in the field of reproductive bilogy have created major influence in the past 50 years, One is the discovery of sperm capacitation and the establishment of in vitro fertilization technology, and the other is the birth of somatic cell nuclear transfer animals. Although researches in reproductive bilogy have developed very quickly and a lot of literatures have been published. many basic theoretical questions are still remained illusive. This paper gives a brief description of our researches during the past decade.展开更多
Objective: Early gestational mammalian fetuses possess the amazing ability to heal cutaneous wounds in a scarless fashion. Over the past years, scientists have been working to decipher the mechanisms underlying this r...Objective: Early gestational mammalian fetuses possess the amazing ability to heal cutaneous wounds in a scarless fashion. Over the past years, scientists have been working to decipher the mechanisms underlying this regenerative repair. The remarkable phenotypic differences between fetal and adult healings behoves us to learn their characteristics in genetics, which represents potentially important mechanisms involved in wound repair observed in fetal versus adult tissues. In this sense, it is reasonable to construct subtractive cDNA library for future research. Methods: Middle laparotomy and hysterotomy were performed on pregnant rabbits at 20 day gestation to expose the fetal back, and a longitudinal incision through the skin was made on the back of the fetus. The traumatized fetal skin was harvested 12 hours post operation, the fetus control and traumatized adult skin specimens were taken at the same time. dscDNA was synthesized from total RNA of skin samples with SMART technology. Taking one of the three samples as Tester respectively and the other two as Drivers, we obtained 1 forward and 2 reverse hybridization products. After being amplified with selective polymerase chain reaction, the products were inserted into a vector, and then transferred into E.coli HB101. The colonies were screened afterwards. Results: The wounded fetuses were alive for a long time even after birth. Every determinant step, such as RNA isolation, cDNA synthesis, Rsa I digestion, adaptor ligation and hybridization, was well operated. Subtractive efficiency identification demonstrated that the suppression subtractive hybridization (SSH) was successful. Insertion into vector and transferring to E.coli were satisfactory. Conclusions: Instead of classic SSH, an improved SSH with 2 Drivers was applied for the experiment. Results confirmed that the improved program was reasonable and correct in both theory and practice. The subtractive cDNA library we have obtained is going to be used for future researches to reveal scarless healing related gene(s) and its (their) expression.展开更多
文摘Alcohol consumption causes cellular injury. Recent developments indicate that ethanol induces epigenetic alterations, particularly acetylation, methylation of histones, and hypo- and hypermethylation of DNA. This has opened up a new area of interest in ethanol research and is providing novel insight into actions of ethanol at the nucleosomal level in relation to gene expression and patho-physiological consequences. The epigenetic effects are mainly attributable to ethanol metabolic stress (Emess), generated by the oxidative and non-oxidative metabolism of ethanol, and dysregulation of methionine metabolism. Epigenetic changes are important in ethanol-induced hepatic steatosis, fibrosis, carcinoma and gastrointestinal injury. This editorial highlights these new advances and its future potential.
基金Supported by Finnish Cancer Organisations,Biocentrum Helsinki,Finlandthe Ministry of Agriculture and Forestry,the Innovation in Food Programme of the National Technology Agency of Finland,and University of Helsinki,Finland
文摘Over the past few years, evidence has accumulated indicating that apart from genetic alterations, epigenetic alterations, through e.g. aberrant promoter methylation, play a major role in the initiation and progression of colorectal cancer (CRC). Even in the hereditary colon cancer syndromes, in which the susceptibility is inherited dominantly, cancer develops only as the result of the progressive accumulation of genetic and epigenetic alterations. Diet can both prevent and induce colon carcinogenesis, for instance, through epigenetic changes, which regulate the homeostasis of the intestinal mucosa. Food-derived compounds are constantly present in the intestine and may shift cellular balance toward harmful outcomes, such as increased susceptibility to mutations. There is strong evidence that a major component of cancer risk may involve epigenetic changes in normal cells that increase the probability of cancer after genetic mutation. The recognition of epigenetic changes as a driving force in colorectal neoplasia would open new areas of research in disease epidemiology, risk assessment, and treatment, especially in mutation carriers who already have an inherited predisposition to cancer.
基金Supported by the National Natural Science Foundation of China, No. 30400147211 Project of Sun Yat-Sen University, No. 98138and the Key Subject Support Grants from Ministry of Public Health No. 2001321
文摘AIM: To observe the therapeutic effect of intrasplenic transplantation with embryonic hepatocytes on amelioration of hereditary copper accumulation in toxic milk (TX) mouse modeling Wilson disease. METHODS: Donor hepatocytes were harvested from 14-d fetal liver of a pregnant homogeneous DL mouse. These cells were successively cultured, labeled with fluorescein dye Hoechst 33342 for 24 h, and sequentially infused into the spleen parenchyma of the recipient TX mice. No host immunosuppression measures were taken. Two and four weeks after transplantation, the recipients were killed for routine histologic investigation and immunohistochemistry study up to 4 wk after transplantation. The serum copper and ceruloplasmin concentrations of the recipient mice were determined by graphite furnace atomic absorption spectroscopy.RESULTS: In the following 2nd and 4th wk after transplantation, the donor hepatocytes could be visualized in the livers of 47.3% recipients. The serum ceruloplasmin and copper concentrations increased by 1.6-fold after 2 wk and 2.0-fold times after 4 wk respectively, which ultimately rose from about 30% of the normal level to nearly 60%(P<0.01). The hepatic copper concentration decreased 7.2%, 4 wk after transplantation. Pathologic examination showed that there were many actively proliferative hepatocyte precursor cells with specific embryonic hepatocyte marker AFP migrated into hepatic sinusoidsof the recipients. A large number of cells carrying hepatocytes marker and albumin were observed in the recipient spleen tissues.CONCLUSION: Embryonic hepatocytes are capable of differentiating into mature hepatocytes in vivo. After transplantation, the hereditary abnormalities of copper metabolism in TX mice could be corrected partially by intrasplenic transplantation of homogeneous embryonic hepatocytes.
基金an introductory part of a project supported by National Science Foundation of China(No.39993430).
文摘As a part of a basic research project on Xeno-transplantion. we have been engaged in the derivation of embryonic stein cell lines from Chinese mini swine. Here, we reported for the first time the establishment of two porcine EG cell lines (BPEG1 and BPEG2) from primordial germ cells of genital ridges of a 28 and a 27 d embryos respectively. Their pluripotent nature has been identified by colony morphology, marker characterization as well as by in vitro and in vivo differentiation. These porcine EG cells are potentially useful for further basic studies.
文摘Hsp90 is a specialized molecular chaperone that is capable of buffering the expression of abnormal phenotypes. Inhibition of Hsp90 activity results in the expression of these phenotypes that are otherwise masked. Selection of offspring from the crossing of affected progenies results in inheritance and enrichment of these phenotypes, which can become independent of their original stimuli. The current combined evidence favours a model involving the interplay between genetics and epigenetics. The recent proteomics efforts to characterize the Hsp90 interaction networks provide further clues into the molecular mechanisms behind this complex phenomenon. This review summarizes the most recent experimental observations and briefly discusses the genetic and epigenetic views used in explaining the different observations.
文摘Objective: To investigate the relation between Shp-2 (a cytoplasmic tyrosine phosphotase) and matrix metalloproteinase-1 (MMP-1) in the migration of mouse embryo fibroblast cell. Methods: Shp-2 -/-embryo fibroblast was separated from Shp-2 knockout mouse on E10. 5, and Shp-2 cDNA was transfected into Shp-2 -/- cell. The cell migration was observed with the wound healing, the MMP-1 expression and secretion was analyzed by immunoblotting and immunoprecipitation. The activation of MMP-1 in the supernatant was detected with type I collagenase activity assay after the stimulation of IL-1α compared with E10. 5 mouse embryo fibroblast cell(Shp-2 +/+). Results: There was obvious migration in Shp-2 +/+ cells and Shp-2 -/-R cells, but not in Shp-2 -/- cells. The shape of Shp-2 -/- cell was epithelial-like. The expression and secretion was increased in Shp-2 +/+ cells and Shp-2 -/-R cells, and it had not changed in Shp-2 -/- cell. The activation of MMP-1 was lower in Shp-2 -/- cells compared to the other cells. Conclusion: IL-1 induces the expression and secretion of MMP-1α at the physical dose, and the cell migration is involved in MMP-1 by way of Shp-2 signal transduction.
文摘The developmental process of Myeloma cells under a digital optical microscope has been inspected and monitored by using time-lapsed recording technique. Myeloma cells were cultured in medium contained 20% and 50% of Fetal Bovine Serum (FBS), respectively. Inspection and monitoring for 6 hours showed the effect of the FBS to mobility, proliferation rate, and development of cell cycle phases of Myeloma cells. Using time-lapsed data, the speed of cells was 3.5-6.0 pm/s when using FBS 20% and increased to 5.0-8.0 p.m/s when using FBS 50%. The rate of cells decreases from 2 cells/hr when using FBS 20% to 1/6 cells/br when using FBS 50%. The cells division process is signified by the change in gray level and it took every 50-70 minutes.
基金National Natural Science Foundation of China(No.50775116)
文摘Combining with Jeffery :quation and mechanics model of fixed point of Euler rigid btdy, the mechanism and method of short fiber radial orientrion and characteristics of movement in tread extrusion process were studied. The influences of tension flow field and shear flow field in flow channel on short fiber orientation trove been systemically analyzed. The extrusion die, which had a hinder dam by adopting such principle, was designed. The results show that the expansion ratio and expanding angle of cross section are the key factors to determine the radial orientation of short fiber. Mathematical model of short fiber radial orientation was established. The results also show that the best expansion ratio is 3 - 4, the expanding angle is 75°, obtaining the average orientation angle between 70°- 80°, and the rationality of the radial oriented mechanism and the mathematical model are verified.
文摘We have examined the myogenic potential of human embryonic stem (hES) cells in a xeno-transplantation animal model. Here we show that precursors differentiated from hES cells can undergo myogenesis in an adult environment and give rise to a range of cell types in the myogenic lineage. This study provides direct evidences that hES cells can regenerate both muscle and satellite cells in vivo and are another promising cell type for treating muscle degenerative disorders in addition to other myogenic cell types.
文摘Validating a method of analysis goes through different steps, which aims at testing the normality of measurements distribution, estimating the uncertainty of the components of a measurement (i.e., accuracy and correctness), and finally, define the control tests of non degradation of the method performances. This paper outlines the steps for validating a biological method of analysis. It involves the construction of an experimental design, a statistical model, and the preparation of an interne laboratory reference material (pilot vaccine). The latter is used to study the impact of deviation and variation factors, in order to, optimize the analytical method, to evaluate the bias (random error), and to calculate the uncertainty of measurement, and make the control charts. This method is applied in the titration of live viral vaccines of Gumboro disease on chicken's embryos fibroblasts. The experimental results show that potential influence factors related to the titration method had no significant influence on the obtained results. Taking into account these results, an operating mode has been elaborated. The finalized method proved to be faithful to standard deviation of repeatability and reproducibility of 0.21 and 0.22, respectively, with a confidence level of 95%. The calculated uncertainty of measurement is equal to 0.2, which represents the average error level of a titer. A homogeneous stock of interne laboratory reference vaccine (MRIL), with an average titer of 5.9 log DIT 50, was produced and the control chart set in away to provide the laboratory with an important tool of control and monitoring of the viral titers evolution in time, as well as, the mastery of the validated titration method performances.
文摘Anxiety is one of the psychological problems in pregnant women that sometimes takes the form of pathological and affects the mental health of mother. The aim of this study was to determine the effects of fetal movement counting on mental health of mother. In a randomized-controlled trial, 208 nulliparous women were randomly divided into two groups. At 28th weeks, both groups completed the GHQ-28. Then the intervention group started to count fetal movements from 28th to 37th weeks of gestation and the control group received routine prenatal care. Again, both groups completed the questionnaire at 37 weeks' gestation and the results were compared. Analysis was performed by SPSS and a P value 〈 0.05 was considered significant. The mean scores of mental health of mothers in 28th and 37th of pregnancy was respectively 23.52 ± 10.23 and 21.09 ± 10.12 in the intervention group and the difference was significant (P = 0.025). The mean in the control group was 23.69 ± 9.43 and 23.88± 8.60 respectively, and the difference was not significant (P = 0.52). In comparing the mean scores between the two groups, it was found that the difference was not significant at 28th weeks of gestation (P = 0.37), but it was significant in 37th week (P = 0.002) and the counting of fetal movements could improve the mental health of mothers compared to control group. The women who had fetal movements counting at weeks 28 to 37 Of gestation reported better mental health than the control group. The mother renorted concerns about decreased fetal movement was similar in the two grouns.
文摘This paper describes the embryonic development of the common cutworm Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) which is divided into eight embryonic stages, through variations in the egg's contents. Experiments were conducted on the eggs ofS. litura under laboratory conditions. The highest concentration of the protein (min.-max.: 32-! 40 lag/egg) and the lowest of the carbohydrate (min.-max.: 3.0-44.0 lag/egg) were obtained; similarly, the DNA content was smaller (min.-max.: 1.0-38.2 lag/egg) than the RNA (min.-max.: 9.2-360.0 lag/egg) throughout the embryogenesis. Three peaks of ecdysteroid titre were observed which were responsible for appearance of particular events during embryogenesis. The last highest peak of 400_+33.4 lag/egg was appeared at 84 h after oviposition when larva was ready to hatch. Therefore, it is concluded that eight embryonic stages in S. litura were characterized by fluctuation in the egg's contents, which were responsible for gradual-progressive embryonic development. The egg-larval development did not show a normal distribution of embryonic developmental-time.
文摘This paper expounds on the tendency of energy supervision reform with consideration to the general background of energy reform. It proposes the following aspects. First, the focus of energy supervision should shift to in-process and post supervision after cancellation or decentralization of energy project approval, Hence, the supervision over construction and completion acceptance is reinforced. Second, with the progression of marketoriented reforms in tire electricity and petroleum sectors, relevant energy authorities should strengthen supervision on key aspects in the electricity and petroleum sectors, particularly by way of specific supervision and problem supervision, in order to keep tire market fair, open and transparent. Third, innovative supervision modes should be adopted to improve supervision performance, so as to realize effective supervision amt finally achieve standardized and normalized energy supervision. These proposals rtTresent both the challenges and tasks that the supervision authorities face but also highlight important chances to realize the energy supervision revolution. Energy enterprises should continuously update thenzselves on the reforms and actions of energy supervision in order to meet the compliance requirements of construction and operation.
文摘The research considered urgent ecological reasons linked to environment such as worn tires, the waste tire rubber's powder was collected from the tire cars repair shops (passed from the sieve No 18 μm), and used to improve the asphalt concrete properties. Raw materials used were prepared and tested. Varies of asphalt concrete mixtures were prepared with different ratios of bitumen (5, 5.5, 6, 6.5, 7% % of concrete weight). The Marshall mix design method was used to determine optimum conditions for bitumen in asphalt concrete with specific weight, stability and flow Test, the optimum amount of bitumen was 6.1% of whole asphalt concrete. The different percentages of waste tire rubber powder (0.0, 0.05, 0.10, 0.15% of bitumen weight) were added in optimum bitumen of asphalt concretes, then specific weight and Marshall test were evaluated. These asphalt-rubber mixtures were found to act quite differently from traditional, unmodified asphalt mixtures. However, these results indicate that improved pavement performance can be achieved with asphalt-rubber binder.
文摘This research was carried out in the area of experimental embryology, which covers from animal fertilization to cloning. Two achievements in the field of reproductive bilogy have created major influence in the past 50 years, One is the discovery of sperm capacitation and the establishment of in vitro fertilization technology, and the other is the birth of somatic cell nuclear transfer animals. Although researches in reproductive bilogy have developed very quickly and a lot of literatures have been published. many basic theoretical questions are still remained illusive. This paper gives a brief description of our researches during the past decade.
文摘Objective: Early gestational mammalian fetuses possess the amazing ability to heal cutaneous wounds in a scarless fashion. Over the past years, scientists have been working to decipher the mechanisms underlying this regenerative repair. The remarkable phenotypic differences between fetal and adult healings behoves us to learn their characteristics in genetics, which represents potentially important mechanisms involved in wound repair observed in fetal versus adult tissues. In this sense, it is reasonable to construct subtractive cDNA library for future research. Methods: Middle laparotomy and hysterotomy were performed on pregnant rabbits at 20 day gestation to expose the fetal back, and a longitudinal incision through the skin was made on the back of the fetus. The traumatized fetal skin was harvested 12 hours post operation, the fetus control and traumatized adult skin specimens were taken at the same time. dscDNA was synthesized from total RNA of skin samples with SMART technology. Taking one of the three samples as Tester respectively and the other two as Drivers, we obtained 1 forward and 2 reverse hybridization products. After being amplified with selective polymerase chain reaction, the products were inserted into a vector, and then transferred into E.coli HB101. The colonies were screened afterwards. Results: The wounded fetuses were alive for a long time even after birth. Every determinant step, such as RNA isolation, cDNA synthesis, Rsa I digestion, adaptor ligation and hybridization, was well operated. Subtractive efficiency identification demonstrated that the suppression subtractive hybridization (SSH) was successful. Insertion into vector and transferring to E.coli were satisfactory. Conclusions: Instead of classic SSH, an improved SSH with 2 Drivers was applied for the experiment. Results confirmed that the improved program was reasonable and correct in both theory and practice. The subtractive cDNA library we have obtained is going to be used for future researches to reveal scarless healing related gene(s) and its (their) expression.