A Plant Biostimulant is any substance or microorganism applied to plants to enhance nutrition efficiency,abioticstress tolerance,and/or crop quality traits,regardless of its nutrient content.The application of Plant b...A Plant Biostimulant is any substance or microorganism applied to plants to enhance nutrition efficiency,abioticstress tolerance,and/or crop quality traits,regardless of its nutrient content.The application of Plant biostimulants(PBs)in production can reduce the application of traditional pesticides and chemical fertilizers and improvethe quality and yield of crops,which is conducive to the sustainable development of agriculture.An in-depthunderstanding of the mechanism and effect of various PBs is very important for how to apply PBs reasonablyand effectively in the practice of crop production.This paper summarizes the main classification of PBs;Thegrowth promotion mechanism of PBs was analyzed from four aspects:improving soil physical and chemical properties,enhancing crop nutrient absorption capacity,photosynthesis capacity,and abiotic stress tolerance;At thesame time,the effects of PBs application on seed germination,seedling vigor,crop yield,and quality were summarized;Finally,how to continue to explore and study the use and mechanism of PBs in the future is analyzedand prospected,to better guide the application of PBs in crop production in the future.展开更多
There is very convincing evidence that a high dietary level of selenium substantially reduces the incidence of a wide variety of animal cancers. The human epidemiological evidence is less clear cut, but overall sugges...There is very convincing evidence that a high dietary level of selenium substantially reduces the incidence of a wide variety of animal cancers. The human epidemiological evidence is less clear cut, but overall suggests that selenium may be protective: the evidence is strongest in men in relation to gastro-intestinal cancers. There is evidence that dietary selenium compounds reduce the formation of DNA adducts by carcinogens. Selenium compounds also inhibit growth in vitro and induce apoptosis. In general, there is a good correlation between the effectiveness of selenium compounds in chemoprevention and growth inhibition, implying that the mechanisms of growth inhibition and chemoprevention may be similar and that a major factor in the chemopreventive effects of selenium compounds in vivo is their ability to retard outgrowth of pre-malignant cells. Various hypotheses have been advanced as to how selenium compounds might prevent tumour cellgrowth. One is that they cause apoptosis by inducing oxidative stress. However, we have shown that the most potent selenium compound, selenodiglutathione (SDG), a natural metabolite of selenite, does not induce oxidative stress, at least not in the sarne way as other oxidants such as H2O2 and diamide. Firstly, a partially selenium-resistant variant cell line does not show increased resistance to H2O2. Moreover, SDG does not induce widespread tyrosine phosphorylation, including MAP and SAN kinases, like other oxidants such as H2O2 and diamide and its effects are not reversed by pretreatment with the tyrosine kinase inhibitor, herbimycin. Our experiments with the selenium-resistant variant suggest that a novel selenium-binding protein may be involved in growth inhibition by selenium展开更多
[Objective] The growth inhibitory effects of garlic polysaccharide(GPS) on human Hep G2 cells were evaluated in this paper. [Method] Hep G2 cells were treated with GPS for 48 h for morphology assay by transition elect...[Objective] The growth inhibitory effects of garlic polysaccharide(GPS) on human Hep G2 cells were evaluated in this paper. [Method] Hep G2 cells were treated with GPS for 48 h for morphology assay by transition electron microscope. Anti-proliferative effects with the same treatment for 24 hand 48 h were assayed by MTT method.Cell cycle distribution and apoptosis assay of treated cells were performed in flow cytometry. [Result] The results showed that GPS enhanced growth inhibitory effect on Hep G2 cells in a time-and dose-dependent manner. PI(Propidium iodide)/Annexin V staining analyzed by FCM(flow cytometry) demonstrated that GPS has a cytotoxic effect on tumor cells. Cell cycle arrest of Hep G2 treated with GPS occurred in G2 phase. [Conclusion] This study suggests that GPS could exert an antitumor effect and could be used as a therapeutic agent for live cancer.展开更多
Estimation of leaf chlorophyll content(LCC) by proximal sensing is an important tool for photosynthesis evaluation in high-throughput phenotyping. The temporal variability of crop biochemical properties and canopy str...Estimation of leaf chlorophyll content(LCC) by proximal sensing is an important tool for photosynthesis evaluation in high-throughput phenotyping. The temporal variability of crop biochemical properties and canopy structure across different growth stages has great impacts on wheat LCC estimation, known as growth stage effects. It will result in the heterogeneity of crop canopy at different growth stages, which would mask subtle spectral response of biochemistry variations. This study aims to explore spectral responses on the growth stage effects and establish LCC models suited for different growth stages. A total number of 864 pairwise samples of wheat canopy spectra and LCC values with 216 observations of each stage were sampled at the tillering, jointing, booting and heading stages in 2021. Firstly, statistical analysis of LCC and spectral response presented different distribution traits and typical spectral variations peak at 470, 520 and 680 nm. Correlation analysis between LCC and reflectance showed typical red edge shifts. Secondly, the testing model of partial least square(PLS) established by the entire datasets to validate the predictive performance at each stage yielded poor LCC estimation accuracy. The spectral wavelengths of red edge(RE) and blue edge(BE) shifts and the poor estimation capability motivated us to further explore the growth stage effects by establishing LCC models at respective growth periods.Finally, competitive adaptive reweighted sampling PLS(CARS-PLS), decision tree(DT) and random forest(RF) were used to select sensitive bands and establish LCC models at specific stages. Bayes optimisation was used to tune the hyperparameters of DT and RF regression. The modelling results indicated that CARS-PLS and DT did not extract specific wavelengths that could decrease the influences of growth stage effects. From the RF out-of-bag(OOB) evaluation, the sensitive wavelengths displayed consistent spectral shifts from BE to GP and from RE to RV from tillering to heading stages. Compared with CARS-PLS and DT,results of RF modelling yielded an estimation accuracy with deviation to performance(RPD) of 2.11, 2.02,3.21 and 3.02, which can accommodate the growth stage effects. Thus, this study explores spectral response on growth stage effects and provides models for chlorophyll content estimation to satisfy the requirement of high-throughput phenotyping.展开更多
Effect of four commonly used pesticides, triadlmefon, jingganmycin, triazoplos andimidacloprid, on grain growth parameters was examined using a growth equation in thepresent paper. Two hundreds of spikes, not damaged ...Effect of four commonly used pesticides, triadlmefon, jingganmycin, triazoplos andimidacloprid, on grain growth parameters was examined using a growth equation in thepresent paper. Two hundreds of spikes, not damaged by pests were simultaneously markedper plot during the heading stage of rice. Rice plants were sprayed at 1 d after marking.Thereafter, 20 spikes were sampled at 4 d intervals and dried in an oven. Then, 10superior and inferior grains were picked from each spike, and brown rice was weighedafter shelling, respectively. First, second and third order derivates were deduced fromthe following grain growth formula:bt-aKwe1+=, where W was the weight of 100 grains brownrice at time t; K was maximum of grain growth; a and b were parameters of the formula. Theparameters were calculated as following:Where R0, △t, GT and Vmax were initial growth power, active growth stage, accumulativeweight of dried content during △t and maximum growth rate, respectively. The resultshowed that GT and K of superior grain following 22.5 and 45 ga.i.ha-1 of imidaclopridsprays were significantly reduced, and △t was significantly decreased for 112.5 and 225ga.i.ha-1 jingganmycin treatments. In addition, the high dose of imidacloprid signifi-cantly reduced the weight of 1000 rice grains by 9.77%. However, there was no significantdifference for the weight of 1000 grains between the high dose of jingganmycin and thecontrol, indicating that effective duration of jingganmycin on grain filling was shorterthan that of imidacloprid.展开更多
The influence of the surface effect on the nanosized spherical void growth in a rigidperfectly plastic material is analyzed and the mechanism of the nanosized void growth with high triaxiality is given. Based on the R...The influence of the surface effect on the nanosized spherical void growth in a rigidperfectly plastic material is analyzed and the mechanism of the nanosized void growth with high triaxiality is given. Based on the Rice and Tracey model for a macro void growth, the present model is proposed to account for the nanosized void growth under a uniform remote strain rate field with consideration on the surface effect. It is concluded that the surface effect yields an evident resistant influence on the nanosized void growth. That is, this influence decays as the void radius increases. With high triaxiality, the nanosized void growth is divided into two stages: the initial stage and the mature stage. At the first stage, the void grows slowly and the influence of surface effect is relatively weak, whereas at the second stage, the influence is significant and the void grows drastically.展开更多
We use Extended Merton model(EMM)for estimating the firm’s credit risks in the presence of inflation.We show quantitatively that inflation is an influential factor making either a benign or adverse effect on the firm...We use Extended Merton model(EMM)for estimating the firm’s credit risks in the presence of inflation.We show quantitatively that inflation is an influential factor making either a benign or adverse effect on the firm’s survival,supporting at the microeconomic level New Keynesian findings of the nonlinear inflation effect on output growth.Lower inflation increasing the firm’s expected rate of return can raise its mean year returns and decrease its default probability.Higher inflation,decreasing the expected rate return,makes the opposite effect.The magnitude of the adverse effect depends on the firm strength:for a steady firm,this effect is small,whereas for a weaker firm,it can be fatal.EMM is the only model taking account of inflation.It can be useful for banks or insurance companies estimating credit risks of commercial borrowers over the debt maturity,and for the firm’s management planning long-term business operations.展开更多
The effects of rare earth on the growth of rice, rape and soybean in three kinds of soils were studied with the method supposed by Economic Co-operation and Development organization (OECD), and the EC50(median growth...The effects of rare earth on the growth of rice, rape and soybean in three kinds of soils were studied with the method supposed by Economic Co-operation and Development organization (OECD), and the EC50(median growth concentration)values were obtained. The inhibition of RE on the growth of rice and rape in red soil and on the growth of soybean in yellow fluvo-aquic soil is higher with stronger poison effects. Compared with other heavy metals such as Hg, Cd, Pb, As, the poison of RE on crops is weaker.展开更多
TFP growth may derive from both technology progress(technical effect) and factor allocation(structural effect). Using China's macroeconomic and industrial data, this paper decomposes China's TFP growth on the ...TFP growth may derive from both technology progress(technical effect) and factor allocation(structural effect). Using China's macroeconomic and industrial data, this paper decomposes China's TFP growth on the basis of growth accounting to cast light on China's growth sources since reform and opening up in 1978. Our study has led to the following findings:(1) From 1978 to 2014, China's economic growth was of generally good quality, and about 1/3 of growth momentum stemmed from a general technology improvement.(2) After 2005, China's late-mover advantage diminished due to narrowed technology gaps with advanced economies. This resulted in a sharp decline in the contribution of technology progress to growth. However, structural effect contributed a steadily increasing share to China's growth.(3) After global financial crisis in 2008, there has been a tendency of reverse technology progress in terms of factor allocation in sectors with excess industrial capacity and other sectors like finance and real estate. Therefore, China should divert its factor resources to more tech-intensive and efficient sectors in the short run, and strive to promote technology progress in all sectors in a longer timeframe.展开更多
Controllable syntheses of different-sized gold nanoclusters are of great significance for their fundamental science and practical applications. In this work, we achieve the controllable and selective syntheses of Au7 ...Controllable syntheses of different-sized gold nanoclusters are of great significance for their fundamental science and practical applications. In this work, we achieve the controllable and selective syntheses of Au7 and Au13 clusters through adding HCl to the traditional Aull synthetic route at different reaction time. Time-dependent mass spectra and UV- Vis spectra were ernployed to monitor these two HCl-directed processes, and revealed the distinct roles of HCl as an etchant or a growth prornotor, respectively. Furthermore, parallel experiments on independent synthetic routes involving only non-chlorine H+ (acetic acid) or Cl (tetraethy larnrnoniurn chloride) instead of HCl were perforrned, which illustrated the main role of H^+-etching and Cl^ -assisted growth in HCl-directed cluster synthetic routes. We propose the HCl-etching is mainly achieved via the H+ action to break the Au(I)-PPh3 part of clusters, while the HCl-prornoted growth is realized via the attachment of Au-Cl species to the pre-forrned clusters.展开更多
[Objectives]This study was conducted to provide reference for plant landscaping,optimization of planting structure and rational allocation of species in Cedrus deodara gardens.[Methods]With three common garden plants ...[Objectives]This study was conducted to provide reference for plant landscaping,optimization of planting structure and rational allocation of species in Cedrus deodara gardens.[Methods]With three common garden plants in northern China,Trifolium repens L.,Poa pratensis L.and Trifolium pratense L.,as receptors,the effects of four concentrations(0.025,0.05,0.075 and 0.10 g/ml)of C.deodara needle extract on seed germination and early seedling growth of the three turfgrasses were studied by the Petri dish filter paper method,using a clear water treatment(0 g/ml)as control check(CK).Data were subjected to analysis of variance(ANOVA)and multiple comparisons(Duncan)using SPSS16.0.[Results]Different concentrations of C.deodara needle extract had significant inhibitory effects on seed germination,radicle and seedling height growth of T.repens,T.pratense and P.pratensis(P<0.05),and the inhibitory effects increased with the increase of concentration.When the concentration reached 0.075 g/ml,seed germination and seedling growth of T.repens stopped,and radicle and seedling growth of T.pratense and P.pratensis also stopped.When the concentration was equal to 0.10 g/ml,germination of T.pratense and P.pratensis seeds was inhibited,and the absolute values of allelopathic index was the largest,that is,the inhibitory effects were the largest.And with the increase of concentration,the absolute value of synthetical allelopathic index also increased.The extract of C.deodara needles contained main allelochemicals leading to the scarcity of understory vegetation.[Conclusions]This study provides a theoretical basis for reasonable garden plant configuration during C.deodara greening and garden landscaping.展开更多
OBJECTIVE: To observe the localization of adrenomedullin (AM) in rat kidney tissue and its inhibitory effect on the growth of cultured rat mesangial cells (MsC). METHODS: A monoclonal antibody against AM developed by ...OBJECTIVE: To observe the localization of adrenomedullin (AM) in rat kidney tissue and its inhibitory effect on the growth of cultured rat mesangial cells (MsC). METHODS: A monoclonal antibody against AM developed by our laboratory was used to detect the localization of AM protein in rat kidney tissue by avidin-biotin complex immunohistochemistry. The expressions of AM and its receptor CRLR mRNA on cultured glomerular epithelial cells (GEC) and MsC were investigated by Northern blot assay, and the possible effect of AM secreted by GEC on MsC proliferation was observed using [3H]thymidine incorporation as an index. RESULTS: A specific monoclonal antibody against AM was succesfully developed. AM was immunohistochemically localized mainly in glomeruli (GEC and endothelial cells), some cortical proximal tubules, medullary collecting duct cells, interstitial cells, vascular smooth muscle cells and endothelial cells. Northern blot assay showed that AM mRNA was expressed only on cultured GEC, but not on MsC, however, AM receptor CRLR mRNA was only expressed on MsC. GEC conditioned medium containing AM can inhibit MsC growth and AM receptor blocker CGRP8-37 may partially decreased this inhibitory effect. CONCLUSION: AM produced by GEC inhibits the proliferation of MsC, which suggests that AM as an important regulator is involved in glomerular normal physiological functions and pathologic processes.展开更多
The analytical method of total resource reallocation effect is an evolution of the analytical method of the factors of economic growth. Since the marketization reform in China in 1978, market mechanism has played a mo...The analytical method of total resource reallocation effect is an evolution of the analytical method of the factors of economic growth. Since the marketization reform in China in 1978, market mechanism has played a more and more important role in resource allocation, and Chinese economy has developed greatly, which is called "the Chinese Miracle". This paper analyzes the economic growth in China from 1978 to 2004 with the analytical method of total resource reallocation effect. The result shows that the annual growth rate of total resource reallocation effect was 0.2%, which was 5.1% of the comprehensive productivity and 0.21% of the gross output growth, i.e. the total resource allocation played a weak role in the economic growth in China. When analyzing it in Chenery's multinational model, we find that Chinese comprehensive productivity growth rate was higher than that in all the income phases of the model, but the total resource allocation effect was obviously lower than that in all the income phases of the model. It indicates that the total resource allocation in China has a great potential, and that to accelerate marketization reform is one of the important issues for Chinese economic development.展开更多
With the method of stem analyses by the microscope, the xylem’s accumulations atdifferent ages were quantitatively studied using the data of typical plant association for Dahurianlarch (Larix gmelini Rupr) and Manchu...With the method of stem analyses by the microscope, the xylem’s accumulations atdifferent ages were quantitatively studied using the data of typical plant association for Dahurianlarch (Larix gmelini Rupr) and Manchurian ash (Fraxinus mandshurica Rupr) mixed forests. Thedeveloping process for this important mixed forest type in the study area was systematically established. The result showed that in the artificial stand of Dahurian larch mixed with naturalManchurian ash. only those which have the same origin as Dahurian larch can grow up before theclosing of stand and form the components of the main layers. After 24 years seif-thinning, when theywere 29 years old, Dahurian larch would be at the stage of no self-thinning. At last the stand woulddevelop to the broad-leaved forests dominating with the Manchurian ash.展开更多
This study determined the effects of selenium on the growth of Fusorium strains and the effects of products extracted from the fungal cultures on relevant indicators of chondrocytes injury.
Growth of In0.52Al0.48As epilayers on InP (100) substrates by molecular beam epitaxy at a wide range of substrate tempreatures (470~550℃) and at different Si doping levels has been carried out. Low temperature photol...Growth of In0.52Al0.48As epilayers on InP (100) substrates by molecular beam epitaxy at a wide range of substrate tempreatures (470~550℃) and at different Si doping levels has been carried out. Low temperature photoluminescence (PL) and double-axis X-ray diffraction (XRD) analyses shaw a strong dependence of the PL and XRD linewidths, XRD intensity ratio (Lepi/Isub), and lattice-mismatch on the substrate temperature. The X-ray diffraction peaks of samples grown at law temperatures show a composition of smaller peaks, indicating the presence of disorder due to alloy clustering. Raman scattering measurements of the same samples show an additional higher energy mode at 273 cm-1 in addition to the InAs-like and AlAs-like longitudinal-optic (LO) phonon modes. Samples doped with Si show an inverted S-shaped dependence of the PL peak energy variation with the temperature which weakens at high doping levels due to a possible reduction in the donor binding energy. Supported be observations of a reduction in both the AlAs-like and InAs-like LO phonon frequencies and a broadening of the LO phonon line shape as the doping level is increased, the PL intensity also shows in increasing degrees at higher doping levels, a temperature dependence which is characteristic of disordered and amorphous materials.展开更多
A pH dependent reduction in growth, Pigment, ATP content, O,' evolution, carbonfixation, Photosynthetic electron transport system, nutrient uptake (NO,' and NH4+),nitrate reductase, and ATPase activities and i...A pH dependent reduction in growth, Pigment, ATP content, O,' evolution, carbonfixation, Photosynthetic electron transport system, nutrient uptake (NO,' and NH4+),nitrate reductase, and ATPase activities and increase in K+ emux of Chlorella vulgaris wasnoticed following supplementation of Cu and Ni to the culture medium. PS II was foundto be more sensitive to both pH and metals than PS I. Though, nitrate reductase (NR) wasmore sensitive to both PH and metals, the ATPase was however, more sensitive t0 metalsbut less sensitive to acidic pH. Acid PH was found to dst the nutrient (NO,' and NH4+)uptake and nitrate reductase in a non-competitive manner. The inhibition Pnduced by thetest metals alone was of noncompetitive type for NO3' uptake, nitrate reductase andATPase and competitive for NH'+ uptake. Acidity not only inhibited the metabolicvariables directly but also through facilitated uptake of metals and increased membranepermeability. A very low sensitivity of ATPase to acidic pH seems to be resgnsible forthe survival of algae in acid environment.展开更多
In 2002, six cohorts ofbroodstock bay scallop Argopecten irradians irradians (Ne=1, 2, 10, 30, 50 and control) were randomly chosen from a population of bay scallop to produce offspring. After one year rearing, with...In 2002, six cohorts ofbroodstock bay scallop Argopecten irradians irradians (Ne=1, 2, 10, 30, 50 and control) were randomly chosen from a population of bay scallop to produce offspring. After one year rearing, with the progeny matured, the similar experiment was done to produce the F2 generation. To determine the magnitude of Ne effects, the growth and survival rates in larvae and adult of six F2 groups were compared. Results showed that inbreeding depression existed not only in the Ne=1 group but also in the Ne=2 group. The growth and survival rates of the two groups were significantly lower than those of the other groups (Ne=10, 30, 50, control), and there were no significant differences among the latter (P〉0.05). At the same time, the amount of depression in the Ne=1 group was significantly higher than that of the Ne=2 group (P〈0.05). These results indicated that the low effective population size (Ne), which increases the possibility of inbreeding, could lead to some harmful effects on the offspring. So it is essential to maintain a high level of Ne in commercial seed production. Fta'thermore, as the high fecundity of bay scallop might lead to increased inbreeding, selecting broodstock from different growout sites is recommended.展开更多
Background The present study aimed to investigate the detailed mode and specific sites for their binding as well as the functional relevance of this binding in the phenotypic proliferation of vascular smooth muscle ce...Background The present study aimed to investigate the detailed mode and specific sites for their binding as well as the functional relevance of this binding in the phenotypic proliferation of vascular smooth muscle cells(SMCs). Methods CREG knocked-down SMCs were employed to evaluate the biological activity of wtCREG and mCREG.Expressions of SMC differentiation markers SM myosin heavy chain(SM-MHC),SM-actin,heavy caldesmon and myocardin were determined by Western blotting using specific antibodies. Cellular growth of SMCs was assessed by bromide dewuridine (BrdU) incorporation and cell cycle analysis on fluorescence-activated cell sorting(FACS).A solid-phase binding assay was used to study the binding of CREG to extracellular domains of M6P/IGF2R.The cellular co-localization of the two recombinant CREGs with M6P/IGF2R was detected on SMC surface by immunoprecipitation and immunofluorescence analysis.Results The molecular weight of wtCREG was around 30 kD while that of the mCREG was~25 kD.Treatment of wtCREG with PNGase F reduced its molecular weight from~30 kD to~25 kD,whereas PNGase F treatment had no effect on the molecular weight of mCREG.Both wtCREG and mCREG proteins enhanced SMC differentiation,inhibited BrdU incorporation,and arrested cell cycle progression when added to the culture medium.In CREG knocked-down SMCs,the amount of CREG detected by immunoblotting in M6P/IGF2R immunoprecipitates was significantly reduced when compared to normal cells.Both recombinant CREGs co-immunoprecipitated with M6P/IGF2R, although slightly reduced amount of the mutant CREG was detected in M6P/IGF2R immunoprecipitates.Immunostaining revealed that His-tagged CREGs co-localized with IGF2R on the cell surface in a glycosylation-independent manner.In vitro binding assay showed that CREGs bound to M6P/ IGF2R extracellular domains 7-10 and 11-13 in a glycosylation -dependent and -independent manner,respectively.Further blocking experiments using soluble M6P/IGF2R fragments and M6P/IGF2R neutralizing antibody indicated that the biological activities of recombinant CREGs in SMC growth and the up-regulation of SMC differentiation markers were all abolished by treatment with the M6P/IGF2R neutralizing antibody. However,although the growth inhibitory effect of wtCREG was nearly abolished by D7-10 or D11-13,the effect of mCREG was only reversed by Dll-13,indicating that the binding to domains 11-13 is required for CREG to modulate the proliferation of SMCs.Conclusions These data suggest that solubleCREG proteins can exert their biological function via binding to the extracellular domains 7-10 and 11-13 of cell surface M6P/IGF2R in both a glycosylation-dependent and -independent manner.展开更多
基金the National Natural Science Foundation of China(No.32001984).
文摘A Plant Biostimulant is any substance or microorganism applied to plants to enhance nutrition efficiency,abioticstress tolerance,and/or crop quality traits,regardless of its nutrient content.The application of Plant biostimulants(PBs)in production can reduce the application of traditional pesticides and chemical fertilizers and improvethe quality and yield of crops,which is conducive to the sustainable development of agriculture.An in-depthunderstanding of the mechanism and effect of various PBs is very important for how to apply PBs reasonablyand effectively in the practice of crop production.This paper summarizes the main classification of PBs;Thegrowth promotion mechanism of PBs was analyzed from four aspects:improving soil physical and chemical properties,enhancing crop nutrient absorption capacity,photosynthesis capacity,and abiotic stress tolerance;At thesame time,the effects of PBs application on seed germination,seedling vigor,crop yield,and quality were summarized;Finally,how to continue to explore and study the use and mechanism of PBs in the future is analyzedand prospected,to better guide the application of PBs in crop production in the future.
文摘There is very convincing evidence that a high dietary level of selenium substantially reduces the incidence of a wide variety of animal cancers. The human epidemiological evidence is less clear cut, but overall suggests that selenium may be protective: the evidence is strongest in men in relation to gastro-intestinal cancers. There is evidence that dietary selenium compounds reduce the formation of DNA adducts by carcinogens. Selenium compounds also inhibit growth in vitro and induce apoptosis. In general, there is a good correlation between the effectiveness of selenium compounds in chemoprevention and growth inhibition, implying that the mechanisms of growth inhibition and chemoprevention may be similar and that a major factor in the chemopreventive effects of selenium compounds in vivo is their ability to retard outgrowth of pre-malignant cells. Various hypotheses have been advanced as to how selenium compounds might prevent tumour cellgrowth. One is that they cause apoptosis by inducing oxidative stress. However, we have shown that the most potent selenium compound, selenodiglutathione (SDG), a natural metabolite of selenite, does not induce oxidative stress, at least not in the sarne way as other oxidants such as H2O2 and diamide. Firstly, a partially selenium-resistant variant cell line does not show increased resistance to H2O2. Moreover, SDG does not induce widespread tyrosine phosphorylation, including MAP and SAN kinases, like other oxidants such as H2O2 and diamide and its effects are not reversed by pretreatment with the tyrosine kinase inhibitor, herbimycin. Our experiments with the selenium-resistant variant suggest that a novel selenium-binding protein may be involved in growth inhibition by selenium
基金Supported by Science and Technology Bureau of Zhengzhou City(141PGJHZ541)
文摘[Objective] The growth inhibitory effects of garlic polysaccharide(GPS) on human Hep G2 cells were evaluated in this paper. [Method] Hep G2 cells were treated with GPS for 48 h for morphology assay by transition electron microscope. Anti-proliferative effects with the same treatment for 24 hand 48 h were assayed by MTT method.Cell cycle distribution and apoptosis assay of treated cells were performed in flow cytometry. [Result] The results showed that GPS enhanced growth inhibitory effect on Hep G2 cells in a time-and dose-dependent manner. PI(Propidium iodide)/Annexin V staining analyzed by FCM(flow cytometry) demonstrated that GPS has a cytotoxic effect on tumor cells. Cell cycle arrest of Hep G2 treated with GPS occurred in G2 phase. [Conclusion] This study suggests that GPS could exert an antitumor effect and could be used as a therapeutic agent for live cancer.
基金supported by the National Key Research and Development Program (2019YFE0125500)University-Locality Integrative Development Project of Yantai (2020XDRHXMPT35)+1 种基金the National Natural Science Foundation of China (31971785 and41801245)the Graduate Training Project of China Agricultural University (JG2019004, JG202026, YW2020007, QYJC202101, and JG202102)。
文摘Estimation of leaf chlorophyll content(LCC) by proximal sensing is an important tool for photosynthesis evaluation in high-throughput phenotyping. The temporal variability of crop biochemical properties and canopy structure across different growth stages has great impacts on wheat LCC estimation, known as growth stage effects. It will result in the heterogeneity of crop canopy at different growth stages, which would mask subtle spectral response of biochemistry variations. This study aims to explore spectral responses on the growth stage effects and establish LCC models suited for different growth stages. A total number of 864 pairwise samples of wheat canopy spectra and LCC values with 216 observations of each stage were sampled at the tillering, jointing, booting and heading stages in 2021. Firstly, statistical analysis of LCC and spectral response presented different distribution traits and typical spectral variations peak at 470, 520 and 680 nm. Correlation analysis between LCC and reflectance showed typical red edge shifts. Secondly, the testing model of partial least square(PLS) established by the entire datasets to validate the predictive performance at each stage yielded poor LCC estimation accuracy. The spectral wavelengths of red edge(RE) and blue edge(BE) shifts and the poor estimation capability motivated us to further explore the growth stage effects by establishing LCC models at respective growth periods.Finally, competitive adaptive reweighted sampling PLS(CARS-PLS), decision tree(DT) and random forest(RF) were used to select sensitive bands and establish LCC models at specific stages. Bayes optimisation was used to tune the hyperparameters of DT and RF regression. The modelling results indicated that CARS-PLS and DT did not extract specific wavelengths that could decrease the influences of growth stage effects. From the RF out-of-bag(OOB) evaluation, the sensitive wavelengths displayed consistent spectral shifts from BE to GP and from RE to RV from tillering to heading stages. Compared with CARS-PLS and DT,results of RF modelling yielded an estimation accuracy with deviation to performance(RPD) of 2.11, 2.02,3.21 and 3.02, which can accommodate the growth stage effects. Thus, this study explores spectral response on growth stage effects and provides models for chlorophyll content estimation to satisfy the requirement of high-throughput phenotyping.
基金supported by the National Natural Science Foundation of China(30070122).
文摘Effect of four commonly used pesticides, triadlmefon, jingganmycin, triazoplos andimidacloprid, on grain growth parameters was examined using a growth equation in thepresent paper. Two hundreds of spikes, not damaged by pests were simultaneously markedper plot during the heading stage of rice. Rice plants were sprayed at 1 d after marking.Thereafter, 20 spikes were sampled at 4 d intervals and dried in an oven. Then, 10superior and inferior grains were picked from each spike, and brown rice was weighedafter shelling, respectively. First, second and third order derivates were deduced fromthe following grain growth formula:bt-aKwe1+=, where W was the weight of 100 grains brownrice at time t; K was maximum of grain growth; a and b were parameters of the formula. Theparameters were calculated as following:Where R0, △t, GT and Vmax were initial growth power, active growth stage, accumulativeweight of dried content during △t and maximum growth rate, respectively. The resultshowed that GT and K of superior grain following 22.5 and 45 ga.i.ha-1 of imidaclopridsprays were significantly reduced, and △t was significantly decreased for 112.5 and 225ga.i.ha-1 jingganmycin treatments. In addition, the high dose of imidacloprid signifi-cantly reduced the weight of 1000 rice grains by 9.77%. However, there was no significantdifference for the weight of 1000 grains between the high dose of jingganmycin and thecontrol, indicating that effective duration of jingganmycin on grain filling was shorterthan that of imidacloprid.
基金the National Natural Science Foundation of China(No.10572110).
文摘The influence of the surface effect on the nanosized spherical void growth in a rigidperfectly plastic material is analyzed and the mechanism of the nanosized void growth with high triaxiality is given. Based on the Rice and Tracey model for a macro void growth, the present model is proposed to account for the nanosized void growth under a uniform remote strain rate field with consideration on the surface effect. It is concluded that the surface effect yields an evident resistant influence on the nanosized void growth. That is, this influence decays as the void radius increases. With high triaxiality, the nanosized void growth is divided into two stages: the initial stage and the mature stage. At the first stage, the void grows slowly and the influence of surface effect is relatively weak, whereas at the second stage, the influence is significant and the void grows drastically.
基金The author is infinitely thankful to his friend and colleague M.Rubinstein for valuable discussions and an invariable interest to his work.The author is also thankful to C.Miller for his high estimation of the author’s efforts.Of course,all errors are author’s full responsibility.
文摘We use Extended Merton model(EMM)for estimating the firm’s credit risks in the presence of inflation.We show quantitatively that inflation is an influential factor making either a benign or adverse effect on the firm’s survival,supporting at the microeconomic level New Keynesian findings of the nonlinear inflation effect on output growth.Lower inflation increasing the firm’s expected rate of return can raise its mean year returns and decrease its default probability.Higher inflation,decreasing the expected rate return,makes the opposite effect.The magnitude of the adverse effect depends on the firm strength:for a steady firm,this effect is small,whereas for a weaker firm,it can be fatal.EMM is the only model taking account of inflation.It can be useful for banks or insurance companies estimating credit risks of commercial borrowers over the debt maturity,and for the firm’s management planning long-term business operations.
文摘The effects of rare earth on the growth of rice, rape and soybean in three kinds of soils were studied with the method supposed by Economic Co-operation and Development organization (OECD), and the EC50(median growth concentration)values were obtained. The inhibition of RE on the growth of rice and rape in red soil and on the growth of soybean in yellow fluvo-aquic soil is higher with stronger poison effects. Compared with other heavy metals such as Hg, Cd, Pb, As, the poison of RE on crops is weaker.
基金supported by CASS Innovation Project“Analysis and Estimation of Innovation-Driven Development”(10620161001005)National Soft Science Program“Industrial Structural Transition,Technology Innovation and Improvement of China’s Economic Growth Potentials”(2014GXS4B073)Center of the Research of Chinese Socialism Theories/Major Program of the National Social Science Foundation of China(NSFC)“Study on Innovation-Driven Development Strategy and Mass Entrepreneurship and Mass Innovation”(2015YZD03)
文摘TFP growth may derive from both technology progress(technical effect) and factor allocation(structural effect). Using China's macroeconomic and industrial data, this paper decomposes China's TFP growth on the basis of growth accounting to cast light on China's growth sources since reform and opening up in 1978. Our study has led to the following findings:(1) From 1978 to 2014, China's economic growth was of generally good quality, and about 1/3 of growth momentum stemmed from a general technology improvement.(2) After 2005, China's late-mover advantage diminished due to narrowed technology gaps with advanced economies. This resulted in a sharp decline in the contribution of technology progress to growth. However, structural effect contributed a steadily increasing share to China's growth.(3) After global financial crisis in 2008, there has been a tendency of reverse technology progress in terms of factor allocation in sectors with excess industrial capacity and other sectors like finance and real estate. Therefore, China should divert its factor resources to more tech-intensive and efficient sectors in the short run, and strive to promote technology progress in all sectors in a longer timeframe.
基金supported by the National Natural Science Foundation of China (No.11475176, No.U1632263, and No.21533007)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (No.11621063)
文摘Controllable syntheses of different-sized gold nanoclusters are of great significance for their fundamental science and practical applications. In this work, we achieve the controllable and selective syntheses of Au7 and Au13 clusters through adding HCl to the traditional Aull synthetic route at different reaction time. Time-dependent mass spectra and UV- Vis spectra were ernployed to monitor these two HCl-directed processes, and revealed the distinct roles of HCl as an etchant or a growth prornotor, respectively. Furthermore, parallel experiments on independent synthetic routes involving only non-chlorine H+ (acetic acid) or Cl (tetraethy larnrnoniurn chloride) instead of HCl were perforrned, which illustrated the main role of H^+-etching and Cl^ -assisted growth in HCl-directed cluster synthetic routes. We propose the HCl-etching is mainly achieved via the H+ action to break the Au(I)-PPh3 part of clusters, while the HCl-prornoted growth is realized via the attachment of Au-Cl species to the pre-forrned clusters.
基金Supported by Gansu Provincial Forestry and Grassland Bureau Science and Technology Project(2019KJ089)Tianshui Science and Technology Program Support Project(2020NCK2106)。
文摘[Objectives]This study was conducted to provide reference for plant landscaping,optimization of planting structure and rational allocation of species in Cedrus deodara gardens.[Methods]With three common garden plants in northern China,Trifolium repens L.,Poa pratensis L.and Trifolium pratense L.,as receptors,the effects of four concentrations(0.025,0.05,0.075 and 0.10 g/ml)of C.deodara needle extract on seed germination and early seedling growth of the three turfgrasses were studied by the Petri dish filter paper method,using a clear water treatment(0 g/ml)as control check(CK).Data were subjected to analysis of variance(ANOVA)and multiple comparisons(Duncan)using SPSS16.0.[Results]Different concentrations of C.deodara needle extract had significant inhibitory effects on seed germination,radicle and seedling height growth of T.repens,T.pratense and P.pratensis(P<0.05),and the inhibitory effects increased with the increase of concentration.When the concentration reached 0.075 g/ml,seed germination and seedling growth of T.repens stopped,and radicle and seedling growth of T.pratense and P.pratensis also stopped.When the concentration was equal to 0.10 g/ml,germination of T.pratense and P.pratensis seeds was inhibited,and the absolute values of allelopathic index was the largest,that is,the inhibitory effects were the largest.And with the increase of concentration,the absolute value of synthetical allelopathic index also increased.The extract of C.deodara needles contained main allelochemicals leading to the scarcity of understory vegetation.[Conclusions]This study provides a theoretical basis for reasonable garden plant configuration during C.deodara greening and garden landscaping.
文摘OBJECTIVE: To observe the localization of adrenomedullin (AM) in rat kidney tissue and its inhibitory effect on the growth of cultured rat mesangial cells (MsC). METHODS: A monoclonal antibody against AM developed by our laboratory was used to detect the localization of AM protein in rat kidney tissue by avidin-biotin complex immunohistochemistry. The expressions of AM and its receptor CRLR mRNA on cultured glomerular epithelial cells (GEC) and MsC were investigated by Northern blot assay, and the possible effect of AM secreted by GEC on MsC proliferation was observed using [3H]thymidine incorporation as an index. RESULTS: A specific monoclonal antibody against AM was succesfully developed. AM was immunohistochemically localized mainly in glomeruli (GEC and endothelial cells), some cortical proximal tubules, medullary collecting duct cells, interstitial cells, vascular smooth muscle cells and endothelial cells. Northern blot assay showed that AM mRNA was expressed only on cultured GEC, but not on MsC, however, AM receptor CRLR mRNA was only expressed on MsC. GEC conditioned medium containing AM can inhibit MsC growth and AM receptor blocker CGRP8-37 may partially decreased this inhibitory effect. CONCLUSION: AM produced by GEC inhibits the proliferation of MsC, which suggests that AM as an important regulator is involved in glomerular normal physiological functions and pathologic processes.
文摘The analytical method of total resource reallocation effect is an evolution of the analytical method of the factors of economic growth. Since the marketization reform in China in 1978, market mechanism has played a more and more important role in resource allocation, and Chinese economy has developed greatly, which is called "the Chinese Miracle". This paper analyzes the economic growth in China from 1978 to 2004 with the analytical method of total resource reallocation effect. The result shows that the annual growth rate of total resource reallocation effect was 0.2%, which was 5.1% of the comprehensive productivity and 0.21% of the gross output growth, i.e. the total resource allocation played a weak role in the economic growth in China. When analyzing it in Chenery's multinational model, we find that Chinese comprehensive productivity growth rate was higher than that in all the income phases of the model, but the total resource allocation effect was obviously lower than that in all the income phases of the model. It indicates that the total resource allocation in China has a great potential, and that to accelerate marketization reform is one of the important issues for Chinese economic development.
文摘With the method of stem analyses by the microscope, the xylem’s accumulations atdifferent ages were quantitatively studied using the data of typical plant association for Dahurianlarch (Larix gmelini Rupr) and Manchurian ash (Fraxinus mandshurica Rupr) mixed forests. Thedeveloping process for this important mixed forest type in the study area was systematically established. The result showed that in the artificial stand of Dahurian larch mixed with naturalManchurian ash. only those which have the same origin as Dahurian larch can grow up before theclosing of stand and form the components of the main layers. After 24 years seif-thinning, when theywere 29 years old, Dahurian larch would be at the stage of no self-thinning. At last the stand woulddevelop to the broad-leaved forests dominating with the Manchurian ash.
基金funded by the Natural Science Basic Research Plan of Shaanxi Province,China(2014JM4170)the Department of disease control of Shaanxi Health and Family Planning Commission,China(2010/2012)
文摘This study determined the effects of selenium on the growth of Fusorium strains and the effects of products extracted from the fungal cultures on relevant indicators of chondrocytes injury.
文摘Growth of In0.52Al0.48As epilayers on InP (100) substrates by molecular beam epitaxy at a wide range of substrate tempreatures (470~550℃) and at different Si doping levels has been carried out. Low temperature photoluminescence (PL) and double-axis X-ray diffraction (XRD) analyses shaw a strong dependence of the PL and XRD linewidths, XRD intensity ratio (Lepi/Isub), and lattice-mismatch on the substrate temperature. The X-ray diffraction peaks of samples grown at law temperatures show a composition of smaller peaks, indicating the presence of disorder due to alloy clustering. Raman scattering measurements of the same samples show an additional higher energy mode at 273 cm-1 in addition to the InAs-like and AlAs-like longitudinal-optic (LO) phonon modes. Samples doped with Si show an inverted S-shaped dependence of the PL peak energy variation with the temperature which weakens at high doping levels due to a possible reduction in the donor binding energy. Supported be observations of a reduction in both the AlAs-like and InAs-like LO phonon frequencies and a broadening of the LO phonon line shape as the doping level is increased, the PL intensity also shows in increasing degrees at higher doping levels, a temperature dependence which is characteristic of disordered and amorphous materials.
文摘A pH dependent reduction in growth, Pigment, ATP content, O,' evolution, carbonfixation, Photosynthetic electron transport system, nutrient uptake (NO,' and NH4+),nitrate reductase, and ATPase activities and increase in K+ emux of Chlorella vulgaris wasnoticed following supplementation of Cu and Ni to the culture medium. PS II was foundto be more sensitive to both pH and metals than PS I. Though, nitrate reductase (NR) wasmore sensitive to both PH and metals, the ATPase was however, more sensitive t0 metalsbut less sensitive to acidic pH. Acid PH was found to dst the nutrient (NO,' and NH4+)uptake and nitrate reductase in a non-competitive manner. The inhibition Pnduced by thetest metals alone was of noncompetitive type for NO3' uptake, nitrate reductase andATPase and competitive for NH'+ uptake. Acidity not only inhibited the metabolicvariables directly but also through facilitated uptake of metals and increased membranepermeability. A very low sensitivity of ATPase to acidic pH seems to be resgnsible forthe survival of algae in acid environment.
基金This study was supported by the Project of Scientific Innovation of the Chinese Academy of Sciences under contract No.ZKCX2-211the Science and Technology Plans of Shandong Province under contract No.022110107the Science and Technology Plans of Qingdao under contract No.03-1-HH-10.
文摘In 2002, six cohorts ofbroodstock bay scallop Argopecten irradians irradians (Ne=1, 2, 10, 30, 50 and control) were randomly chosen from a population of bay scallop to produce offspring. After one year rearing, with the progeny matured, the similar experiment was done to produce the F2 generation. To determine the magnitude of Ne effects, the growth and survival rates in larvae and adult of six F2 groups were compared. Results showed that inbreeding depression existed not only in the Ne=1 group but also in the Ne=2 group. The growth and survival rates of the two groups were significantly lower than those of the other groups (Ne=10, 30, 50, control), and there were no significant differences among the latter (P〉0.05). At the same time, the amount of depression in the Ne=1 group was significantly higher than that of the Ne=2 group (P〈0.05). These results indicated that the low effective population size (Ne), which increases the possibility of inbreeding, could lead to some harmful effects on the offspring. So it is essential to maintain a high level of Ne in commercial seed production. Fta'thermore, as the high fecundity of bay scallop might lead to increased inbreeding, selecting broodstock from different growout sites is recommended.
文摘Background The present study aimed to investigate the detailed mode and specific sites for their binding as well as the functional relevance of this binding in the phenotypic proliferation of vascular smooth muscle cells(SMCs). Methods CREG knocked-down SMCs were employed to evaluate the biological activity of wtCREG and mCREG.Expressions of SMC differentiation markers SM myosin heavy chain(SM-MHC),SM-actin,heavy caldesmon and myocardin were determined by Western blotting using specific antibodies. Cellular growth of SMCs was assessed by bromide dewuridine (BrdU) incorporation and cell cycle analysis on fluorescence-activated cell sorting(FACS).A solid-phase binding assay was used to study the binding of CREG to extracellular domains of M6P/IGF2R.The cellular co-localization of the two recombinant CREGs with M6P/IGF2R was detected on SMC surface by immunoprecipitation and immunofluorescence analysis.Results The molecular weight of wtCREG was around 30 kD while that of the mCREG was~25 kD.Treatment of wtCREG with PNGase F reduced its molecular weight from~30 kD to~25 kD,whereas PNGase F treatment had no effect on the molecular weight of mCREG.Both wtCREG and mCREG proteins enhanced SMC differentiation,inhibited BrdU incorporation,and arrested cell cycle progression when added to the culture medium.In CREG knocked-down SMCs,the amount of CREG detected by immunoblotting in M6P/IGF2R immunoprecipitates was significantly reduced when compared to normal cells.Both recombinant CREGs co-immunoprecipitated with M6P/IGF2R, although slightly reduced amount of the mutant CREG was detected in M6P/IGF2R immunoprecipitates.Immunostaining revealed that His-tagged CREGs co-localized with IGF2R on the cell surface in a glycosylation-independent manner.In vitro binding assay showed that CREGs bound to M6P/ IGF2R extracellular domains 7-10 and 11-13 in a glycosylation -dependent and -independent manner,respectively.Further blocking experiments using soluble M6P/IGF2R fragments and M6P/IGF2R neutralizing antibody indicated that the biological activities of recombinant CREGs in SMC growth and the up-regulation of SMC differentiation markers were all abolished by treatment with the M6P/IGF2R neutralizing antibody. However,although the growth inhibitory effect of wtCREG was nearly abolished by D7-10 or D11-13,the effect of mCREG was only reversed by Dll-13,indicating that the binding to domains 11-13 is required for CREG to modulate the proliferation of SMCs.Conclusions These data suggest that solubleCREG proteins can exert their biological function via binding to the extracellular domains 7-10 and 11-13 of cell surface M6P/IGF2R in both a glycosylation-dependent and -independent manner.