[Objective] This study aimed to investigate the changes in activity of POD and CAT in wheat during generation period under drought stress. [Method] Four wheat cultivars, including Yunong 51, Zhoumai 22, Jimai 19 and H...[Objective] This study aimed to investigate the changes in activity of POD and CAT in wheat during generation period under drought stress. [Method] Four wheat cultivars, including Yunong 51, Zhoumai 22, Jimai 19 and Huaimai 22, were selected as experimental materials and cultured under drought stress simulated by different concentrations of PEG6000, to determine the activity of POD and CAT. [Result] POD and CAT activity in wheat during generation period increased gradual y under stress of 5% and 15% PEG6000 from 0 to 120 h; POD and CAT activity in wheat under stress of 15% PEG6000 increased more compared with that under stress of 5% PEG6000; POD and CAT activity in wheat under stress of 25% and 35% PEG6000 increased first and then decreased. Stress duration significantly af-fected the activity of POD and CAT in wheat during generation period. [Conclusion] This study provided theoretical references for breeding drought-tolerant wheat.展开更多
Methyl jasmonate （MeJA） is a plant-signaling molecule that regulates plant morphogenesis and expression of plant defense genes. To determine the role of the endogenous MeJA levels in the development of plants, trans...Methyl jasmonate （MeJA） is a plant-signaling molecule that regulates plant morphogenesis and expression of plant defense genes. To determine the role of the endogenous MeJA levels in the development of plants, transgenic soybean [Glycine max （L.） Merrill] plants harboring NTR1 gene encoding for jasmonic acid carboxyl methyltransferase （JMT） were produced. The activation of NTR1 gene expression resulted in the production of MeJA. Overexpression of the NTR1 cDNA under the regulation of cauliflower mosaic virus （CaMV） 35S promoter in the transgenic soybean plants was confirmed using Northern blot analysis. The significant differences in leaf and root growth patterns were observed between the transgenic plants and the wild-type plants. The leaves of the transgenic plants were slightly elongated in length but dramatically narrowed in width compared with the nontrans-formed wild-type plants. In addition, elongation of primary root was inhibited in the overexpressed transgenic soybean plantlets, whereas the development of lateral root was stimulated relative to the nontransformed plants. The leaves of the transgenic plants showed 2-2.5-fold higher levels of MeJA than the control plants. These results indicated that the increased endogenous levels of MeJA is involved in regulation of morphogenesis in soybean plants.展开更多
[ Objective] The study was to understand the changes of amylase（AMY） and superoxide dismutase（SOD） isozymes during the ger- mination process of Emmenopterys henryi Oliv seeds. [ Metbod] By employing polyacrylamide...[ Objective] The study was to understand the changes of amylase（AMY） and superoxide dismutase（SOD） isozymes during the ger- mination process of Emmenopterys henryi Oliv seeds. [ Metbod] By employing polyacrylamide gel electrophoresis method, the expressions of AMY and SOD isozymes during seed germination process were analyzed. ~ Result] The main AMY bands remained strong during the whole peri- od and a new band A2 appeared in the middle and late period of seed germination. Some new SOD bands occurred at the early stage, then be- came weak or disappeared in the middle period, and band S6 became intense in the late peried. [ Conclusion.] The expression of AMY and SOD isozyme gene has temporal difference during germination of E. henryi Oliv seeds.展开更多
Cell cycle kinetic activity in the cortical cells of the lentil (Lens culinaris Me-die. cv. Verte du Puy) primary root during germination was examined both temporally and spatially. Immunohistochemical and cytological...Cell cycle kinetic activity in the cortical cells of the lentil (Lens culinaris Me-die. cv. Verte du Puy) primary root during germination was examined both temporally and spatially. Immunohistochemical and cytological evidence indicated that DNA replication and cell division started in the cortical cells of tire lentil primary root after around 13 and 17 h of imbibition, respectively. The first cells in DNA synthesis and the First mitotic figures all appeared in the cortical cells about I mm front the root-cap junction, but these divided cells had synthesized their DNA during the maturity of seed instead of during germination. The kinetic pattern of activity of the first cell cycle showed that these cells were not activated synchronously, but re-entered the cell cycle in turn depending on their places in the root tip, However, the adjacent cells partially synchronously proceeded their cell cycle.展开更多
[Objective] This study aimed to explore the effects of treatments with three types of exogenous oxidase solutions and H2O2.solution on the somatic embryogenesis of Fraxinus mandshurica Rupr. （Oleaceae）. [Method] The...[Objective] This study aimed to explore the effects of treatments with three types of exogenous oxidase solutions and H2O2.solution on the somatic embryogenesis of Fraxinus mandshurica Rupr. （Oleaceae）. [Method] The immature zygotic cotyledons were treated with PPQ （polyphenol oxidase） solution, GQD （glucose oxidase） solution, SOD （superoxide dismutase） solution and H202 （hydrogen peroxide） at different concentrations to explore the effects on the growth, browning and somatic embryogenesis on cotyledon explants in the somatic embryogenesis of F. mandshurica. Through comparative analysis on the effects of different treatments on somatic embryogenesis of F. mandshurica, the relationship between explants browning and somatic embryogenesis was uncovered during the somatic embryogenesis of F. mandshurica. [Result] H2O2 treatment not only advanced the explants browning, but also inhibited the growth and somatic embryogenesis of explants; different concentrations of PPQ promoted the growth and browning of explants, as well as improving the incidence of somatic embryogenesis; both GOD and SOD treatment could raise the explants browning rate; when somatic embryogenesis of explants treated with enzyme solutions advanced, the incidence of somatic embryogenesis was low; however, when the disparity of the incidence of somatic embryogenesis between 30 and 60 d treatments reached its peak, the incidence of somatic embryogenesis was also high. [Conclusion] The results of this study provide basis for raising the incidence and improving the status of somatic embryogenesis of F. mandshurica, as well as optimizing the somatic embryogenesis system of F. mandshurica.展开更多
Metabolism of hydrogen peroxide in the course of embryonic development ofsilkworm (variety Guang) was determined by using colorimetric analysis and oxygen electrodemethod. The results indicated that: 1) In the course ...Metabolism of hydrogen peroxide in the course of embryonic development ofsilkworm (variety Guang) was determined by using colorimetric analysis and oxygen electrodemethod. The results indicated that: 1) In the course of fertilization (0-4 h after egg laying), thelevel of H_2O_2 content reached its peak value at 2.5 h of the developmental course and the activity ofsuperoxidase dismutase (SOD) was at higher level while the activity of catalase (CAT) at the lowestcorrespondingly; 2) The H_2O_2 content in embryo, in which the diapause of eggs was being relievedthrough treatment with hydrochloric acid on time in the course of embryonic development, wassignificantly higher than that of diapause eggs except the lower level showed in the embryo whenthe development of it went on for 168~216 h and the activity of SOD reached, lower and higher,tWo peaks in 72 and 168 h after egg-laying, respectively, and was significantly higher in late stagewhile the activity of CAT was shown with a stable level in the period of 72-192 h after egg-laying,and, after then, a rapid rising occurred in the embryo. The level of the CAT activity in embryowas shown significantly lower than that in diapause eggs in early period and higher in late stage ofegg development; 3) In the course of formation of diapause in eggs, the level of H_2O_2contentchanged smoothly and the activity of SOD changed vigorously in early period, and kept stable statelater; and the CAT activity increased gradually; while in the course of relief of diapause under ontime-treatment with hydrochloric acid, the level of H_2O_2 was significantly higher than that indiapause eggs and the SOD activity displayed a new peak value and significantly rose in later stage,while the activity of CAT in relieving embryo from diapause was signincantly lower than that indiapause eggs. Combining the results obtained in other researches with those from ours mentionedabove, we suggest that the metabolism of H_2O_2 might be of importance in the courses of formationand relief of diapause in silkworm eggs. Maybe the esterase A4 timer hypothesis and themicropylar barrier to oxygen hypothesis could be integrated for explanation of the course offormation and relief of diapause in silkworm eggs.展开更多
[Objective] This study aimed to investigate the effect of hydrogen peroxide on the seed germination of eggplant （Solanum melongena L.） Luba 2.[Method] The seeds of Luba 2 were separately soaked in 20％,40％,60％ and...[Objective] This study aimed to investigate the effect of hydrogen peroxide on the seed germination of eggplant （Solanum melongena L.） Luba 2.[Method] The seeds of Luba 2 were separately soaked in 20％,40％,60％ and 80％ hydrogen peroxide solution for 2,5 and 10 min before seed germination.The germination rate and days to reach the maximum germination rate were calculated.[Result] Treatment with low concentrations （20％） of hydrogen peroxide for 2 and 5 min made eggplant Luba 2 germinate in advance,and shortened the time to reach the maximum germination rate.Treatment with high concentrations （60％ and 80％） of hydrogen peroxide solution for longer time （10 min） caused significant damage to the seeds,delayed seed germination,and reduced the germination rate.[Conclusion] This study will provide theoretical references for the production practices of eggplant.展开更多
Pollen morphology and hydration, ovule development, formation of pollination drop and the pollination process of Taxus chinensis (Pilg.) Rehd were investigated in detail. The results showed that mature pollen was ...Pollen morphology and hydration, ovule development, formation of pollination drop and the pollination process of Taxus chinensis (Pilg.) Rehd were investigated in detail. The results showed that mature pollen was one_celled, irregular in shape, nonsaccate, and the surface was covered with orbicules. When pollen became hydrated, the intine swelled and the exine bursted. The exine usually remained on the surface of water or on the pollination drop all the time, while the rest portion of the pollen sank into the drop of water or the pollination drop. In the late August, the down_curved female buds could be observed in the field trees. The downturning of the female buds was an characteristic feature discriminating from the vegetative buds. At this stage ovular primordium was present in the female bud with a dome_shaped nucellar primordium encircled by a rudimentary integument. The integument grew fast and overgrew the nucellus. In the March of the following year, the ovule formed a micropylar canal about 1?000 μm in length, 200-300 μm in width. Except the micropyle, the other part of the ovule was enclosed by 20-25 scales. During the early stage of the ovule development, the nucellar surface clearly showed cell configuration; but a membrane_like structure covering the nucellar apex appeared in the late stage of the ovule development, and subsequently broke down with nucellar cell disintegration before pollen shedding. The disintegrated cell products might partake in the formation of the pollination drop. Before and during pollination, the nucellar cells contained abundant mitochondria, endospermic reticulum and dictysomes with vesicles; the plasma membrane was undulated and there was no accumulation of electron_dense substances in the pericytoplasm. Pollination drops usually occurred at night, and disappeared by noon in the field tree. 15 days before pollination, the in vitro ovules from the field trees already had the capability of producing pollination drops, which could last for 4-5 days indoors. However, after these drops received pollen, they did not withdraw noticeably compared with the unpollinated ones. The retraction of the pollination drop was presumed not to be a nonmetabolic outcome but rather a result of evaporation.展开更多
[ Objective ] The research aimed to reveal theeffects of excessive Mg^2＋ on the germination characteristics of maize and soybean. [ Method ] Eleven concentration gradients of Mg^2＋ including 0, 40, 80, 120, 160,200,...[ Objective ] The research aimed to reveal theeffects of excessive Mg^2＋ on the germination characteristics of maize and soybean. [ Method ] Eleven concentration gradients of Mg^2＋ including 0, 40, 80, 120, 160,200,240,280,320,360 and 400 mmol/L were set up to study the effects of different treatments on such indices as the germination potential, germination rate, fresh weight, dry weight, root length, plant height and stem diameter of maize and soybean. [ Result] With the increasing of Mg^2＋ concentration, the germination of maize delayed and the germination rate of soybean obviously decreased, reaching the significant difference at 0.05 level. When Mg^2＋ concentration increased, the fresh weight and dry weight of maize and soybean decreased, but maize and soybean showed some adaptability. The growth of radicles and seedlings in maize and soybean were obviously inhibited by Mg^2＋ , and atrophy and dysplasia phenomena appeared. [ Conclusion] Excessive Mg^2＋ stress has different effects on the germination potential and germination rate of different crops and has obvious poisoning effects on the root and stem growth of crops.展开更多
＂Over＂ phenomenon exists in all fields of society, and over thoughts and behaviors not only waste resources, but also destroy the ecological environment.Landscape design is also facing the dilemma of over planning, ...＂Over＂ phenomenon exists in all fields of society, and over thoughts and behaviors not only waste resources, but also destroy the ecological environment.Landscape design is also facing the dilemma of over planning, over design and over construction. Based on the paraphrase and explanation of ＂degree＂, the principle for modest landscape design with the concept of sustainable development was explored through the analysis on the concept of sustainable development, which emphasized the ＂degree＂ standard in landscape design, and the combination of regional features with native features to carry out ecological design, with the aim to facilitate the landscape designers to design the ＂modest＂ landscape with sustainable development.展开更多
An immunosuppressive animal model induced by physical stress that forced mice to swim in cold water(14±1℃)and the restorative effect of Tremella polysac charide(TP)on the suppressed immune function by stress wer...An immunosuppressive animal model induced by physical stress that forced mice to swim in cold water(14±1℃)and the restorative effect of Tremella polysac charide(TP)on the suppressed immune function by stress were studied in mice.It was found that the spleen plaque forming cell(PFC)response to sheep red blood cells,delayed cuta- neous hypersensitivity(DCH)induced by dinitrochlorobenzene and the lymphocyte prolifer- ation stimulated by concanavalin A(Con A)were significantly decreased in stressed mice. In addition.the maximal decrease of PFC was reached in 9-12 days after stress.A- drenolectomy could not affect the decrease of PFC in stressed mice.TP(200.400mg/kg) ig for 8-14 days significantly restored the PFC.DCH and lymphocyte proliferation to nor- mal level in stressed mice.展开更多
The peroxyoxalate chemiluminescence(CL)detection of fatty acids in human se- rum combined with high-performance liquid chromatography (HPLC)is described.Some fatty acids in serum were extracted with a 1 :1(v/v)mixture...The peroxyoxalate chemiluminescence(CL)detection of fatty acids in human se- rum combined with high-performance liquid chromatography (HPLC)is described.Some fatty acids in serum were extracted with a 1 :1(v/v)mixture of chloroform-n-heptane.2-(4-Hydrazinocarbonyl- phenyl)-4,5-diphenylimidazole (HCPI) was used as a fluorescent labelling reagent of the fatty acids. The labelling reaction was carried out at 30℃ for 1 h at pH 6.5 and the resulting reaction mixture was sudjected to HPLC. The labelled fatty acid C_(17)(P-C_(17))was used as the internal standard. The la- belled fatty acids C_(16) and C_(18) were separated within 18 min on an ODS-8OTM column (150 mm× 6 mm ID,5μm,Tosoh Japan).The calibrlation curves of fatty acids from the spiked control serum were Y_1=-0.003 7 + 0.0028X_1,r=0.994 for FA C_( 16) and Y_2=0.00 1 2 + 0.00098X_2,r=0.999 for FA C_( 18),respectively.The average recoveries of facids from the spiked contrl serum were 107.2%(n=8,RSD=4.3%)for FA C_(16) and 97.35%(n=8, RSD=4.0%)for FA C_(18),respectively.The lower detection limits of fatty acids after reaction were 12μmol per 20μl injection for FA C_(16) and 18 μmol per 20μl injection for FA C_(18),respectively(signal to noise ratio, S/N=2).The HPLC/CL method was applied to the determination of FA C_(16) and FA C_(18) in normal human serum and the results showed that the concentrations of fatty acids in normal human serum were 0.134 ± 0.009 μ mol/ml serum(n=5) for FA C_(16) and 0.052±0.028 μmol/ml serum(n=5)for FA C_(18),respectively.展开更多
Pepsinogens are zymogens of pepsins,aspecific proteases working as digestive enzymes in vertebrate stomach,of which biological and molecular properties have been extensively studied.Several exhaustive studies have bee...Pepsinogens are zymogens of pepsins,aspecific proteases working as digestive enzymes in vertebrate stomach,of which biological and molecular properties have been extensively studied.Several exhaustive studies have been performed in the pepsinogen producing cells in developing rat stomachs,but little is known about the expression of pepsinogen gene in these cells.In this study,the ontogeny of pepsinogen producing cells in rat fundic glands was studied by in situ hybridization using a digoxigenin-labeled RNA probe.The rat gastric epithelium was stratified but was morphologically undifferentiated at the stage of 18.5 days of gestation.The pepsinogen mRNA was expressed both in chief cells and mucous neck cells in adult rats,which was first detected by in situ hybridization in the stomach of the rats at 3.5 days after birth.The development of pepsinogen producing cells could be classified into four stages:(1) 18.5 days of gestation to 0.5 day after birth;(2) 3.5 days to 2 weeks after birth;(3) 3～4 weeks after birth;(4) 8 weeks after birth.Pepsinogen expression is strictly limited to these cells,the distribution of which shown a developmental stage-specific manner.We concluded the pepsinogen C could offer excellent molecular markers of differentiation during stomach epithelial cellulur development.展开更多
This article presents a multiscale simulation approach starting at the molecular level for the adsorption process development. A grand canonical Monte Carlo method is used for the prediction of adsorption isotherms of...This article presents a multiscale simulation approach starting at the molecular level for the adsorption process development. A grand canonical Monte Carlo method is used for the prediction of adsorption isotherms of methanol on an activated carbon at the molecular level. The adsorption isotherms obtained in the linear region （or adsorption constant） are exploited as a model parameter required for the adsorption process simulation. The adsorption process model described by a set of partial differential equations （PDEs） is solved by using the conservation element and solution element method, which produces a fast and an accurate numerical solution to PDEs. The simulation results obtained from the adsorption constant estimated at the molecular level are in good agreement with the experimental results of the pulse response. The systematical multiscale simulation approach addressed in this study may be useful to accelerate the adsorption process development by reducing the number of experiments.展开更多
A novel bat-like ZnO nanostructure was synthesized on the silicon substrate by simple ther- mal evaporation of zinc powders without any catalyst. Each bat-like nanorod （＂nanobat＂） is composed of a hexagonal head, ...A novel bat-like ZnO nanostructure was synthesized on the silicon substrate by simple ther- mal evaporation of zinc powders without any catalyst. Each bat-like nanorod （＂nanobat＂） is composed of a hexagonal head, a continuous neck and a thin handle. High-resolution transmission electron microscopy and selected area electron diffraction results reveal the single-crystalline feature and the growing direction along [0001] of the nanobat. The vapor- solid mechanism was found suitable to explain the growth process of the nanobat and a schematic model was proposed in detail based on the experimental results.展开更多
Salt-forming regions for a complex salt-water system in non-equilibrium state of evaporation process are usually different from those in solubility diagrams.To understand the solid-forming region of NaCl and improve t...Salt-forming regions for a complex salt-water system in non-equilibrium state of evaporation process are usually different from those in solubility diagrams.To understand the solid-forming region of NaCl and improve the utilization of bittern resources,experiments were carried out to evaporate 20 representative mixture solution samples of Na ^＋,Mg ^2＋ //Cl^-, SO4^2--H2O system with an average evaporation intensity of（1.4±0.4） g·L^-1 ·min^-1（water） at boiling temperature 348 K,and determine the NaCl solid-forming regions in non-equilibrium state.Because of the complexity of salt-forming region,a maximal region and a minimal region were proposed to express the non-equilibrium state salt-forming region with different crystal seed,and a conditional salt-forming region was proposed to present the characteristic region of non-equilibrium salt-forming phase diagram.The areas of the maximal and minimal regions are 2.00 and 1.56 times those in solubility diagram,so it is possible to utilize bittern resources in high efficiency.The recovery rates of NaCl were 99.65%,93.14%,88.57%,72.76%,and 83.68%for six typical bittern sources from Tulantai Salt Lake（China）,Dongtai Salt Lake（China） ,Jilantai Salt Lake（China）,Qarun Salt Lake（Egypt） and seawater,respectively.It is testified that the non-equilibrium state salt-forming phase diagram can be used in industrial processes.展开更多
On-line estimation of unmeasurable biological variables is important in fermentation processes,directly influencing the optimal control performance of the fermentation system as well as the quality and yield of the ta...On-line estimation of unmeasurable biological variables is important in fermentation processes,directly influencing the optimal control performance of the fermentation system as well as the quality and yield of the targeted product.In this study,a novel strategy for state estimation of fed-batch fermentation process is proposed.By combining a simple and reliable mechanistic dynamic model with the sample-based regressive measurement model,a state space model is developed.An improved algorithm,swarm energy conservation particle swarm optimization(SECPSO) ,is presented for the parameter identification in the mechanistic model,and the support vector machines(SVM) method is adopted to establish the nonlinear measurement model.The unscented Kalman filter(UKF) is designed for the state space model to reduce the disturbances of the noises in the fermentation process.The proposed on-line estimation method is demonstrated by the simulation experiments of a penicillin fed-batch fermentation process.展开更多
Biomass is a key factor in fermentation process, directly influencing the performance of the fermentation system as well as the quality and yield of the targeted product. Therefore, the on-line estimation of biomass i...Biomass is a key factor in fermentation process, directly influencing the performance of the fermentation system as well as the quality and yield of the targeted product. Therefore, the on-line estimation of biomass is indispensable. The soft-sensor based on support vector machine （SVM） for an on-line biomass estimation was analyzed in detail, and the improved SVM called the weighted least squares support vector machine was presented to follow the dynamic feature of fermentation process. The model based on the modified SVM was developed and demonstrated using simulation experiments.展开更多
基金Supported by Natural Science Fund of Education Department of Anhui Province(KJ2012B188)General Science and Research Program of Suzhou College(2011yyb13)~~
文摘[Objective] This study aimed to investigate the changes in activity of POD and CAT in wheat during generation period under drought stress. [Method] Four wheat cultivars, including Yunong 51, Zhoumai 22, Jimai 19 and Huaimai 22, were selected as experimental materials and cultured under drought stress simulated by different concentrations of PEG6000, to determine the activity of POD and CAT. [Result] POD and CAT activity in wheat during generation period increased gradual y under stress of 5% and 15% PEG6000 from 0 to 120 h; POD and CAT activity in wheat under stress of 15% PEG6000 increased more compared with that under stress of 5% PEG6000; POD and CAT activity in wheat under stress of 25% and 35% PEG6000 increased first and then decreased. Stress duration significantly af-fected the activity of POD and CAT in wheat during generation period. [Conclusion] This study provided theoretical references for breeding drought-tolerant wheat.
基金This work was supported by the Shandong Provincial Education Department Foundation (No. J05K04).
文摘Methyl jasmonate （MeJA） is a plant-signaling molecule that regulates plant morphogenesis and expression of plant defense genes. To determine the role of the endogenous MeJA levels in the development of plants, transgenic soybean [Glycine max （L.） Merrill] plants harboring NTR1 gene encoding for jasmonic acid carboxyl methyltransferase （JMT） were produced. The activation of NTR1 gene expression resulted in the production of MeJA. Overexpression of the NTR1 cDNA under the regulation of cauliflower mosaic virus （CaMV） 35S promoter in the transgenic soybean plants was confirmed using Northern blot analysis. The significant differences in leaf and root growth patterns were observed between the transgenic plants and the wild-type plants. The leaves of the transgenic plants were slightly elongated in length but dramatically narrowed in width compared with the nontrans-formed wild-type plants. In addition, elongation of primary root was inhibited in the overexpressed transgenic soybean plantlets, whereas the development of lateral root was stimulated relative to the nontransformed plants. The leaves of the transgenic plants showed 2-2.5-fold higher levels of MeJA than the control plants. These results indicated that the increased endogenous levels of MeJA is involved in regulation of morphogenesis in soybean plants.
文摘[ Objective] The study was to understand the changes of amylase（AMY） and superoxide dismutase（SOD） isozymes during the ger- mination process of Emmenopterys henryi Oliv seeds. [ Metbod] By employing polyacrylamide gel electrophoresis method, the expressions of AMY and SOD isozymes during seed germination process were analyzed. ~ Result] The main AMY bands remained strong during the whole peri- od and a new band A2 appeared in the middle and late period of seed germination. Some new SOD bands occurred at the early stage, then be- came weak or disappeared in the middle period, and band S6 became intense in the late peried. [ Conclusion.] The expression of AMY and SOD isozyme gene has temporal difference during germination of E. henryi Oliv seeds.
文摘Cell cycle kinetic activity in the cortical cells of the lentil (Lens culinaris Me-die. cv. Verte du Puy) primary root during germination was examined both temporally and spatially. Immunohistochemical and cytological evidence indicated that DNA replication and cell division started in the cortical cells of tire lentil primary root after around 13 and 17 h of imbibition, respectively. The first cells in DNA synthesis and the First mitotic figures all appeared in the cortical cells about I mm front the root-cap junction, but these divided cells had synthesized their DNA during the maturity of seed instead of during germination. The kinetic pattern of activity of the first cell cycle showed that these cells were not activated synchronously, but re-entered the cell cycle in turn depending on their places in the root tip, However, the adjacent cells partially synchronously proceeded their cell cycle.
基金Supported by National Natural Science Foundation of China(30872008)the Special Fund for Basic Research of Central Universities(DL10BA04)~~
文摘[Objective] This study aimed to explore the effects of treatments with three types of exogenous oxidase solutions and H2O2.solution on the somatic embryogenesis of Fraxinus mandshurica Rupr. （Oleaceae）. [Method] The immature zygotic cotyledons were treated with PPQ （polyphenol oxidase） solution, GQD （glucose oxidase） solution, SOD （superoxide dismutase） solution and H202 （hydrogen peroxide） at different concentrations to explore the effects on the growth, browning and somatic embryogenesis on cotyledon explants in the somatic embryogenesis of F. mandshurica. Through comparative analysis on the effects of different treatments on somatic embryogenesis of F. mandshurica, the relationship between explants browning and somatic embryogenesis was uncovered during the somatic embryogenesis of F. mandshurica. [Result] H2O2 treatment not only advanced the explants browning, but also inhibited the growth and somatic embryogenesis of explants; different concentrations of PPQ promoted the growth and browning of explants, as well as improving the incidence of somatic embryogenesis; both GOD and SOD treatment could raise the explants browning rate; when somatic embryogenesis of explants treated with enzyme solutions advanced, the incidence of somatic embryogenesis was low; however, when the disparity of the incidence of somatic embryogenesis between 30 and 60 d treatments reached its peak, the incidence of somatic embryogenesis was also high. [Conclusion] The results of this study provide basis for raising the incidence and improving the status of somatic embryogenesis of F. mandshurica, as well as optimizing the somatic embryogenesis system of F. mandshurica.
文摘Metabolism of hydrogen peroxide in the course of embryonic development ofsilkworm (variety Guang) was determined by using colorimetric analysis and oxygen electrodemethod. The results indicated that: 1) In the course of fertilization (0-4 h after egg laying), thelevel of H_2O_2 content reached its peak value at 2.5 h of the developmental course and the activity ofsuperoxidase dismutase (SOD) was at higher level while the activity of catalase (CAT) at the lowestcorrespondingly; 2) The H_2O_2 content in embryo, in which the diapause of eggs was being relievedthrough treatment with hydrochloric acid on time in the course of embryonic development, wassignificantly higher than that of diapause eggs except the lower level showed in the embryo whenthe development of it went on for 168~216 h and the activity of SOD reached, lower and higher,tWo peaks in 72 and 168 h after egg-laying, respectively, and was significantly higher in late stagewhile the activity of CAT was shown with a stable level in the period of 72-192 h after egg-laying,and, after then, a rapid rising occurred in the embryo. The level of the CAT activity in embryowas shown significantly lower than that in diapause eggs in early period and higher in late stage ofegg development; 3) In the course of formation of diapause in eggs, the level of H_2O_2contentchanged smoothly and the activity of SOD changed vigorously in early period, and kept stable statelater; and the CAT activity increased gradually; while in the course of relief of diapause under ontime-treatment with hydrochloric acid, the level of H_2O_2 was significantly higher than that indiapause eggs and the SOD activity displayed a new peak value and significantly rose in later stage,while the activity of CAT in relieving embryo from diapause was signincantly lower than that indiapause eggs. Combining the results obtained in other researches with those from ours mentionedabove, we suggest that the metabolism of H_2O_2 might be of importance in the courses of formationand relief of diapause in silkworm eggs. Maybe the esterase A4 timer hypothesis and themicropylar barrier to oxygen hypothesis could be integrated for explanation of the course offormation and relief of diapause in silkworm eggs.
基金Supported by Special Fund of Beijing Academy of Agriculture and Forestry Sciences for Distinguished Young Scholars (QNJJ201211)National Key Technology Research and Development Program (2012BAK26B03)+1 种基金Special Fund of Beijing Academy of Agriculture and Forestry Sciences for Scientific and Technological Innovation (KJCX201202001,KJCX201101010)Key Project Fund of Beijing Municipal Commission of Science and Technology (D131100000413001)~~
文摘[Objective] This study aimed to investigate the effect of hydrogen peroxide on the seed germination of eggplant （Solanum melongena L.） Luba 2.[Method] The seeds of Luba 2 were separately soaked in 20％,40％,60％ and 80％ hydrogen peroxide solution for 2,5 and 10 min before seed germination.The germination rate and days to reach the maximum germination rate were calculated.[Result] Treatment with low concentrations （20％） of hydrogen peroxide for 2 and 5 min made eggplant Luba 2 germinate in advance,and shortened the time to reach the maximum germination rate.Treatment with high concentrations （60％ and 80％） of hydrogen peroxide solution for longer time （10 min） caused significant damage to the seeds,delayed seed germination,and reduced the germination rate.[Conclusion] This study will provide theoretical references for the production practices of eggplant.
文摘Pollen morphology and hydration, ovule development, formation of pollination drop and the pollination process of Taxus chinensis (Pilg.) Rehd were investigated in detail. The results showed that mature pollen was one_celled, irregular in shape, nonsaccate, and the surface was covered with orbicules. When pollen became hydrated, the intine swelled and the exine bursted. The exine usually remained on the surface of water or on the pollination drop all the time, while the rest portion of the pollen sank into the drop of water or the pollination drop. In the late August, the down_curved female buds could be observed in the field trees. The downturning of the female buds was an characteristic feature discriminating from the vegetative buds. At this stage ovular primordium was present in the female bud with a dome_shaped nucellar primordium encircled by a rudimentary integument. The integument grew fast and overgrew the nucellus. In the March of the following year, the ovule formed a micropylar canal about 1?000 μm in length, 200-300 μm in width. Except the micropyle, the other part of the ovule was enclosed by 20-25 scales. During the early stage of the ovule development, the nucellar surface clearly showed cell configuration; but a membrane_like structure covering the nucellar apex appeared in the late stage of the ovule development, and subsequently broke down with nucellar cell disintegration before pollen shedding. The disintegrated cell products might partake in the formation of the pollination drop. Before and during pollination, the nucellar cells contained abundant mitochondria, endospermic reticulum and dictysomes with vesicles; the plasma membrane was undulated and there was no accumulation of electron_dense substances in the pericytoplasm. Pollination drops usually occurred at night, and disappeared by noon in the field tree. 15 days before pollination, the in vitro ovules from the field trees already had the capability of producing pollination drops, which could last for 4-5 days indoors. However, after these drops received pollen, they did not withdraw noticeably compared with the unpollinated ones. The retraction of the pollination drop was presumed not to be a nonmetabolic outcome but rather a result of evaporation.
基金Key Project of‘Rejuvenating the Northeast China’ Science and Technology Action Plan of Chinese Academy of Sciences(DB2X-2-027)National Key Basic Research Program(2004CB418506)~~
文摘[ Objective ] The research aimed to reveal theeffects of excessive Mg^2＋ on the germination characteristics of maize and soybean. [ Method ] Eleven concentration gradients of Mg^2＋ including 0, 40, 80, 120, 160,200,240,280,320,360 and 400 mmol/L were set up to study the effects of different treatments on such indices as the germination potential, germination rate, fresh weight, dry weight, root length, plant height and stem diameter of maize and soybean. [ Result] With the increasing of Mg^2＋ concentration, the germination of maize delayed and the germination rate of soybean obviously decreased, reaching the significant difference at 0.05 level. When Mg^2＋ concentration increased, the fresh weight and dry weight of maize and soybean decreased, but maize and soybean showed some adaptability. The growth of radicles and seedlings in maize and soybean were obviously inhibited by Mg^2＋ , and atrophy and dysplasia phenomena appeared. [ Conclusion] Excessive Mg^2＋ stress has different effects on the germination potential and germination rate of different crops and has obvious poisoning effects on the root and stem growth of crops.
文摘＂Over＂ phenomenon exists in all fields of society, and over thoughts and behaviors not only waste resources, but also destroy the ecological environment.Landscape design is also facing the dilemma of over planning, over design and over construction. Based on the paraphrase and explanation of ＂degree＂, the principle for modest landscape design with the concept of sustainable development was explored through the analysis on the concept of sustainable development, which emphasized the ＂degree＂ standard in landscape design, and the combination of regional features with native features to carry out ecological design, with the aim to facilitate the landscape designers to design the ＂modest＂ landscape with sustainable development.
文摘An immunosuppressive animal model induced by physical stress that forced mice to swim in cold water(14±1℃)and the restorative effect of Tremella polysac charide(TP)on the suppressed immune function by stress were studied in mice.It was found that the spleen plaque forming cell(PFC)response to sheep red blood cells,delayed cuta- neous hypersensitivity(DCH)induced by dinitrochlorobenzene and the lymphocyte prolifer- ation stimulated by concanavalin A(Con A)were significantly decreased in stressed mice. In addition.the maximal decrease of PFC was reached in 9-12 days after stress.A- drenolectomy could not affect the decrease of PFC in stressed mice.TP(200.400mg/kg) ig for 8-14 days significantly restored the PFC.DCH and lymphocyte proliferation to nor- mal level in stressed mice.
文摘The peroxyoxalate chemiluminescence(CL)detection of fatty acids in human se- rum combined with high-performance liquid chromatography (HPLC)is described.Some fatty acids in serum were extracted with a 1 :1(v/v)mixture of chloroform-n-heptane.2-(4-Hydrazinocarbonyl- phenyl)-4,5-diphenylimidazole (HCPI) was used as a fluorescent labelling reagent of the fatty acids. The labelling reaction was carried out at 30℃ for 1 h at pH 6.5 and the resulting reaction mixture was sudjected to HPLC. The labelled fatty acid C_(17)(P-C_(17))was used as the internal standard. The la- belled fatty acids C_(16) and C_(18) were separated within 18 min on an ODS-8OTM column (150 mm× 6 mm ID,5μm,Tosoh Japan).The calibrlation curves of fatty acids from the spiked control serum were Y_1=-0.003 7 + 0.0028X_1,r=0.994 for FA C_( 16) and Y_2=0.00 1 2 + 0.00098X_2,r=0.999 for FA C_( 18),respectively.The average recoveries of facids from the spiked contrl serum were 107.2%(n=8,RSD=4.3%)for FA C_(16) and 97.35%(n=8, RSD=4.0%)for FA C_(18),respectively.The lower detection limits of fatty acids after reaction were 12μmol per 20μl injection for FA C_(16) and 18 μmol per 20μl injection for FA C_(18),respectively(signal to noise ratio, S/N=2).The HPLC/CL method was applied to the determination of FA C_(16) and FA C_(18) in normal human serum and the results showed that the concentrations of fatty acids in normal human serum were 0.134 ± 0.009 μ mol/ml serum(n=5) for FA C_(16) and 0.052±0.028 μmol/ml serum(n=5)for FA C_(18),respectively.
文摘Pepsinogens are zymogens of pepsins,aspecific proteases working as digestive enzymes in vertebrate stomach,of which biological and molecular properties have been extensively studied.Several exhaustive studies have been performed in the pepsinogen producing cells in developing rat stomachs,but little is known about the expression of pepsinogen gene in these cells.In this study,the ontogeny of pepsinogen producing cells in rat fundic glands was studied by in situ hybridization using a digoxigenin-labeled RNA probe.The rat gastric epithelium was stratified but was morphologically undifferentiated at the stage of 18.5 days of gestation.The pepsinogen mRNA was expressed both in chief cells and mucous neck cells in adult rats,which was first detected by in situ hybridization in the stomach of the rats at 3.5 days after birth.The development of pepsinogen producing cells could be classified into four stages:(1) 18.5 days of gestation to 0.5 day after birth;(2) 3.5 days to 2 weeks after birth;(3) 3～4 weeks after birth;(4) 8 weeks after birth.Pepsinogen expression is strictly limited to these cells,the distribution of which shown a developmental stage-specific manner.We concluded the pepsinogen C could offer excellent molecular markers of differentiation during stomach epithelial cellulur development.
基金the Basic Research Program of the Korea Science & Engineering Foundation (KoSEF, No. R01-2006-000-10786-0).
文摘This article presents a multiscale simulation approach starting at the molecular level for the adsorption process development. A grand canonical Monte Carlo method is used for the prediction of adsorption isotherms of methanol on an activated carbon at the molecular level. The adsorption isotherms obtained in the linear region （or adsorption constant） are exploited as a model parameter required for the adsorption process simulation. The adsorption process model described by a set of partial differential equations （PDEs） is solved by using the conservation element and solution element method, which produces a fast and an accurate numerical solution to PDEs. The simulation results obtained from the adsorption constant estimated at the molecular level are in good agreement with the experimental results of the pulse response. The systematical multiscale simulation approach addressed in this study may be useful to accelerate the adsorption process development by reducing the number of experiments.
文摘A novel bat-like ZnO nanostructure was synthesized on the silicon substrate by simple ther- mal evaporation of zinc powders without any catalyst. Each bat-like nanorod （＂nanobat＂） is composed of a hexagonal head, a continuous neck and a thin handle. High-resolution transmission electron microscopy and selected area electron diffraction results reveal the single-crystalline feature and the growing direction along [0001] of the nanobat. The vapor- solid mechanism was found suitable to explain the growth process of the nanobat and a schematic model was proposed in detail based on the experimental results.
基金Supported by the National Natural Science Foundation of China（20776110） the Natural Science Foundation of Tianjin（06YFJMJC04100）
文摘Salt-forming regions for a complex salt-water system in non-equilibrium state of evaporation process are usually different from those in solubility diagrams.To understand the solid-forming region of NaCl and improve the utilization of bittern resources,experiments were carried out to evaporate 20 representative mixture solution samples of Na ^＋,Mg ^2＋ //Cl^-, SO4^2--H2O system with an average evaporation intensity of（1.4±0.4） g·L^-1 ·min^-1（water） at boiling temperature 348 K,and determine the NaCl solid-forming regions in non-equilibrium state.Because of the complexity of salt-forming region,a maximal region and a minimal region were proposed to express the non-equilibrium state salt-forming region with different crystal seed,and a conditional salt-forming region was proposed to present the characteristic region of non-equilibrium salt-forming phase diagram.The areas of the maximal and minimal regions are 2.00 and 1.56 times those in solubility diagram,so it is possible to utilize bittern resources in high efficiency.The recovery rates of NaCl were 99.65%,93.14%,88.57%,72.76%,and 83.68%for six typical bittern sources from Tulantai Salt Lake（China）,Dongtai Salt Lake（China） ,Jilantai Salt Lake（China）,Qarun Salt Lake（Egypt） and seawater,respectively.It is testified that the non-equilibrium state salt-forming phase diagram can be used in industrial processes.
基金Supported by the National Natural Science Foundation of China（20476007 20676013）
文摘On-line estimation of unmeasurable biological variables is important in fermentation processes,directly influencing the optimal control performance of the fermentation system as well as the quality and yield of the targeted product.In this study,a novel strategy for state estimation of fed-batch fermentation process is proposed.By combining a simple and reliable mechanistic dynamic model with the sample-based regressive measurement model,a state space model is developed.An improved algorithm,swarm energy conservation particle swarm optimization(SECPSO) ,is presented for the parameter identification in the mechanistic model,and the support vector machines(SVM) method is adopted to establish the nonlinear measurement model.The unscented Kalman filter(UKF) is designed for the state space model to reduce the disturbances of the noises in the fermentation process.The proposed on-line estimation method is demonstrated by the simulation experiments of a penicillin fed-batch fermentation process.
基金Supported by the National Natural Science Foundation of China （No.20476007）.
文摘Biomass is a key factor in fermentation process, directly influencing the performance of the fermentation system as well as the quality and yield of the targeted product. Therefore, the on-line estimation of biomass is indispensable. The soft-sensor based on support vector machine （SVM） for an on-line biomass estimation was analyzed in detail, and the improved SVM called the weighted least squares support vector machine was presented to follow the dynamic feature of fermentation process. The model based on the modified SVM was developed and demonstrated using simulation experiments.
