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991.
Abstract

The effect of acetic acid vapours at three application times on grey and blue moulds on the incidence of apple fruits was studied. Acetic acid vapour at 6 µl/l caused complete inhibition of linear growth and spore germination of Botrytis cinerea and Penicillium sp. The most effective concentration was AA at 4 µl/l, which reduced spore germination and linear growth by more than 82.4 and 68.3% of both fungi respectively compared with un-fumigated fungi. On other trials the diameter of the inhibited growth zone of both fungi gradually increased as AA concentrations increased. The highest increase in inhibition zone diameter was obtained with AA at 12 µl/l followed by AA at 8 µl/l, meanwhile AA at 4 µl/l had a moderate effect. Apple fruits were divided into three groups, the first was fumigated at 24 h before inoculation, the second at zero time the and third at 24 h after inoculation and storage for 30 days. Results indicate that the higher reduction of grey and blue mould incidence was obtained with AA at 12 µl/l of three application times which reduced the disease incidence by more than 81.0, 81.0 and 73.5% before, at zero time and after inoculation, respectively. Acetic acid at 8 µl/l reduced the incidence of both diseases more than 52.0% with all application times. As for application times the most effective times were 24 before and at the zero time of inoculation which reduced both diseases more than 81.0 and 75.5 with AA vapours at 12 and 8 µl/l, respectively. Meanwhile treated apple fruits after inoculation was less effective. The same trend between disease incidence and percentage of rotted tissue parts was observed. It could be suggested that acetic acid vapours might be safely used commercially for controlling post-harvest disease of apple fruits during storage.  相似文献   
992.
Blue carbon ecosystems (BCEs) are important nature-based solutions for climate change-mitigation. However, current debates question the reliability and contribution of BCEs under future climatic-scenarios. The answer to this question depends on ecosystem processes driving carbon-sequestration and -storage, such as primary production and decomposition, and their future rates. We performed a global meta-analysis on litter decomposition rate constants (k) in BCEs and predicted changes in carbon release from 309 studies. The relationships between k and climatic factors were examined by extracting remote-sensing data on air temperature, sea-surface temperature, and precipitation aligning to the decomposition time of each experiment. We constructed global numerical models of litter decomposition to forecast k and carbon release under different scenarios. The current k averages at 27 ± 3 × 10−2 day−1 for macroalgae were higher than for seagrasses (1.7 ± 0.2 × 10−2 day−1), mangroves (1.6 ± 0.1 × 10−2 day−1) and tidal marshes (5.9 ± 0.5 × 10−3 day−1). Macrophyte k increased with both air temperature and precipitation in intertidal BCEs and with sea surface temperature for subtidal seagrasses. Above a temperature threshold for vascular plant litter at ~25°C and ~20°C for macroalgae, k drastically increased with increasing temperature. However, the direct effect of high temperatures on k are obscured by other factors in field experiments compared with laboratory experiments. We defined “fundamental” and “realized” temperature response to explain this effect. Based on relationships for realized temperature response, we predict that proportions of decomposed litter will increase by 0.9%–5% and 4.7%–28.8% by 2100 under low- (2°C) and high-warming conditions (4°C) compared to 2020, respectively. Net litter carbon sinks in BCEs will increase due to higher increase in litter C production than in decomposition by 2100 compared to 2020 under RCP 8.5. We highlight that BCEs will play an increasingly important role in future climate change-mitigation. Our findings can be leveraged for blue carbon accounting under future climate change scenarios.  相似文献   
993.
The green algal genus Cylindrocystis is widespread in various types of environments, including extreme habitats. However, very little is known about its diversity, especially in polar regions. In the present study, we isolated seven new Cylindrocystis-like strains from terrestrial and freshwater habitats in Svalbard (High Arctic). We aimed to compare the new isolates on a molecular (rbcL and 18S rDNA), morphological (light and confocal laser scanning microscopy), and cytological (Raman microscopy) basis. Our results demonstrated that the Arctic Cylindrocystis were not of a monophyletic origin and that the studied strains clustered within two clades (tentatively named the soil and freshwater/glacier clades) and four separate lineages. Morphological data (cell size, shape, and chloroplast morphology) supported the presence of several distinct taxa among the new isolates. Moreover, the results showed that the Arctic Cylindrocystis strains were closely related to strains originating from the temperate zone, indicating high ecological versatility and successful long-distance dispersal of the genus. Large amounts of inorganic polyphosphate (polyP) grains were detected within the chloroplasts of the cultured Arctic Cylindrocystis strains, suggesting effective luxury uptake of phosphorus. Additionally, various intracellular structures were identified using Raman microscopy and cytochemical and fluorescent staining. This study represents the first attempt to combine molecular, morphological, ecological, and biogeographical data for Arctic Cylindrocystis. Our novel cytological observations partially explain the success of Cylindrocystis-like microalgae in polar regions.  相似文献   
994.
Sodium ion battery (SIB) as a next‐generation battery has been drawing much attention due to the abundance and even distribution of sodium source. Metal sulfides with high theoretical capacity and good electrical conductivity are promising anode candidates for SIB, however, the structural collapse caused by severe volume change during the de/sodiation process typically results in a fast capacity decay, limited rate capability, and cycling stability. In this work, by careful composition and structure design, polydopamine coated Prussian blue analogs derived carbon coated bimetallic sulfide hollow nanocubes (PBCS) are prepared with distinguished morphology, higher surface area, smaller charge transfer resistance, and higher sodium diffusion coefficient than the uncoated bimetallic sulfides. An optimum carbon coated bimetallic sulfide hollow nanocube anode delivers a specific capacity of ≈500 mA h g?1 at 50 mA g?1 with ethylene carbonate/dimethyl carbonate (1:1, vol%) electrolyte in the presence of fluoroethylene carbonate additives. A capacity of 122.3 mA h g?1 can be realized at 5000 mA g?1, showing good rate performance. In addition the carbon coated bimetallic sulfide hollow nanocubes can maintain capacity of 87 mA h g?1 after being cycled at 500 mA g?1 for 150 times, indicating its good cycling stability. The structure integrity, high specific capacity, good rate performance, and cycling stability of PBCS render it a promising anode material for advanced SIB.  相似文献   
995.
染料结合法测定荞麦种子蛋白质含量的研究   总被引:1,自引:0,他引:1  
郭玉珍  陈庆富 《广西植物》2007,27(6):952-957
以考马斯亮蓝G250为染料,结合经典的凯氏定氮法测定结果,对影响染料结合法测定蛋白质含量的振荡时间、温度、考马斯亮蓝溶液浓度等因素进行了研究,并分析了由考马斯亮蓝染料和蛋白质结合后染料结合量(OD值差)与凯氏法测得的蛋白质百分含量之间的相关性。结果表明:测定的适宜条件是:温度15℃,处理时间50min,考马斯亮蓝溶液的浓度是0.06mg/mL。此条件形成的络合物较稳定,重复性较好,并且所测的染料结合量与凯氏定氮法测得的蛋白质含量间呈极显著的一元线性回归和相关关系。栽培甜荞和栽培苦荞的回归方程分别为:y=15.364x+3.865和y=10.769x+6.287,这两个回归方程差异显著,不能合并,分别适合于快速估计甜荞和苦荞种子的蛋白质含量。  相似文献   
996.
A blue light– (peak at 470 nm) induced photomovement was observed in the filamentous eukaryotic algae, Spirogyra spp. When Spirogyra filaments were scattered in a water chamber under a unilateral light source, they rapidly aligned toward the light source in 1 h and bound with neighboring filaments to form thicker parallel bundles of filaments. The filaments in the anterior of the bundles curved toward the light first and then those in the posterior began to roll up toward the light, forming an open‐hoop shape. The bundle of filaments then moved toward the light source by repeated rolling and stretching of filaments. When the moving bundle met other filaments, they joined and formed a bigger mat. The coordination of filaments was essential for the photomovement. The average speed of movement ranged between 7.8 and 13.2 μm·s?1. The movement was induced in irradiance level from 1 to 50 μmol photons·m?2·s?1. The filaments of Spirogyra showed random bending and stretching movement under red or far‐red light, but the bundles did not move toward the light source. There was no distinct diurnal rhythm in the photomovement of Spirogyra spp.  相似文献   
997.
Multiparameter flow cytometry was used to identify and sort subpopulations of cells from pleural cell populations harvested from the rat without employing special stains or fluorochrome-labeled monoclonal antibodies. Cell parameters measured included electronic volume, axial light loss, 90° light scatter, and blue autofluorescence. Various bivariate combinations of these parameters were used to distinctly resolve pleural macrophages, eosinophils, mast cells, and lymphocytes. These subpopulations were separately sorted viably according to their unique electrooptical phenotypic characteristics in>90% purity. Our multiparameter flow cytometric approach, accordingly, provides a means by which pleural cell subpopulations may be easily obtained for subsequent in vitro study. Moreover, the general strategy for identifying and isolating these subpopulations may be usefully extended to the identification and isolation of subpopulations of cells occurring in other complex cell mixtures.  相似文献   
998.
Pygmy blue whales ( Balaenoptera musculus brevicauda ) are ≤24.1 m and are generally found north of 52°S in summer, whereas the more southerly Antarctic blue whales ( B. m. intermedia ) may exceed 30 m. Previous assessments have assumed that catches and recent surveys south of 60°S recorded Antarctic blue whales, but these may have included pygmy blue whales. Here, we use ovarian corpora, which accumulate with ovulations and hence with length, to separate these subspecies. The resulting Bayesian mixture model, applied to 1,380 Northern Region (north of 52°S and 35°–180°E) and 3,844 Southern Ocean (south of 52°S) blue whales, estimated that only 0.1% (95% credibility intervals 0.0%–0.4%) of the Antarctic region blue whales were pygmy blue whales and, unexpectedly, found significantly lower lifetime ovulation counts for pygmy blue whales than for Antarctic blue whales (7.6 vs . 13.6). Over four decades, despite substantial depletion of Antarctic blue whales, there was no trend in the estimated proportion of pygmy blue whales in the Antarctic. Several lines of investigation found no evidence for sizeable numbers of pygmy blue whales in ovarian corpora data collected in the 1930s, as was previously hypothesized.  相似文献   
999.
1000.
Astrocytes are extensively coupled through gap junctions (GJs) that are composed of channels mostly constituted by connexin43 (Cx43). This astroglial gap junctional intercellular communication (GJIC) allows propagation of ions and signaling molecules critical for neuronal activity and survival. It is drastically inhibited by a short-term exposure to endothelin-1 (ET-1) or to sphingosine-1-phosphate (S1P), both compounds being inflammatory mediators acting through activation of GTP-binding protein-coupled receptors (GPCRs). Previously, we have identified the GTPases G(i/o) and Rho as key actors in the process of S1P-induced inhibition. Here, we asked whether similar mechanisms underlied the effects of ET-1 and S1P by investigating changes in the phosphorylation status of Cx43 and in the molecular associations of Cx43 with zonula occludens (ZO) proteins and occludin. We showed that the inhibitory effect of ET-1 on GJIC was entirely dependent on the activation of G(i/o) but not on Rho and Rho-associated kinase. Both ET-1 and S1P induced dephosphorylation of Cx43 located at GJs through a process mediated by G(i/o) and calcineurin. Thanks to co-immunoprecipitation approaches, we found that a population of Cx43 (likely junctional Cx43) was associated to ZO-1-ZO-2-occludin multiprotein complexes and that acute treatments of astrocytes with ET-1 or S1P induced a G(i/o)-dependent increase in the amount of Cx43 linked to these complexes. As a whole, this study identifies a new mechanism of GJIC regulation in which two GPCR agonists dynamically alter interactions of Cx43 with its molecular partners.  相似文献   
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