Three sizes of CuO nanosheets were synthesized by hydrothermal method. The structure and morphology of CuO nanosheets were characterized by X-ray diffraction and scanning electron microscopy. ...Dielectrophoresis nano-manipulation technique was employed to arrange the materials on pre-designed Ti/Au electrodes to fabricate the three humidity sensors, and the sensing properties were then tested. The experimental results show that the sensitivity greatly increases with the decreasing size of CuO nanosheets, the sensitivity of sensor a, b, c are 369%, 3278%, 22,611% in 97.3% RH, respectively. The smaller sized CuO nanomaterials have better response characteristic, the response time of sensor a, b, c under 11.3–97.3% RH are 53 s, 49 s, 32 s, respectively. And correspondingly, hysteresis properties and the repeatability are also a little influenced. In addition, based on complex impedance spectroscopy and multilayer adsorption theory, the impact of size on humidity sensing property was discussed. The results indicated the feasibility to obtain higher performance of humidity sensor, especially the higher sensitivity, via employment the smaller size sensing nanomaterials.
Graphic Abstract
Perennial ryegrass (Lolium perenne L.) is widely used as cool-season turfgrass; however, its growth is mainly limited by cold and drought stress. The interplay between melatonin and brassinosteroids ...in enhancing tolerance to cold and drought stress and their underlying molecular mechanisms is poorly understood so far. In this study, melatonin enhanced cold and drought tolerance in perennial ryegrass depended on the duration of dose and the level of stress. Although melatonin activates the expression of NADPH oxidase-related genes post-exposure to short-term cold/drought stresses, the accumulation of H2O2 was reduced under long-term stress. This increase in antioxidant activity was correlated with an increase of genes expressed in their antioxidant system and ascorbate-glutathione cycle. Moreover, the exogenous melatonin induced the biosynthesis of melatonin and brassinosteroids or the expression of signaling-related genes. However, the expression of brassinosteroids biosynthesis and signaling-related genes were inhibited in the rbohC and rbohF mutants in the presence of melatonin. The inhibition of H2O2 production attenuated melatonin-mediated growth in the Arabidopsis wild-type as well as bak1 and bri1.9 mutants. DMTU inhibited the mitigation effect of melatonin on the H2O2 accumulation in WT and LpBAK1 transgenic plants, while a lighter DAB staining was observed in the LpBAK1 transgenic seedlings. Consistently, the chemical scavenging of H2O2 impaired the effect of melatonin as well as brassinosteroids on seed germination and the root growth of perennial ryegrass. The current study reveals a novel regulatory mechanism of the crosstalk between H2O2 and brassinosteroid signaling in melatonin-induced cold/drought tolerance in perennial ryegrass.
•Melatonin positively regulates cold and drought stress tolerance.•Melatonin-mediated stress tolerance is associated with H2O2 metabolism.•Melatonin induces the biosynthesis and signaling of brassinosteroids and H2O2.•Crosstalk of H2O2 and brassinosteroid involves in melatonin-induced stress tolerance.•Melatonin-BRs-H2O2 network activates the expression of stress-related genes.
With the rapid development of Internet, the network gradually changes from simple static information carrier into platform on which people express their views and show personality. Faced with such a ...sea of emotional information-rich text, it is urgent to find method of a quick orientation calculation on the large-scale text. Orientation calculation of words is the basis of orientation calculation on the large-scale text. Aiming at the problem that is orientation calculation of words relies mainly upon benchmark words, the paper builds dynamic benchmark set in accordance with part of speech of words and provides the method of semantic orientation calculation of words based on dynamic benchmark set. The proposed method is tested on test set contains verbs and adjectives and more than 90% accuracy have been achieved, which shows the validity and rationality of the method.
Text Clustering Algorithm Based on Lexical Graph Yun Sha; Guoying Zhang; Huina Jiang
Fourth International Conference on Fuzzy Systems and Knowledge Discovery (FSKD 2007),
2007-Aug., Letnik:
2
Conference Proceeding
Text clustering methods can group text into thematic clusters, which is an important topic in many fields, such as search engine. The well-known methods of text clustering, however, do not really ...address the special problems of text clustering because of the very high dimensionality data and understandability of the cluster description. An algorithm for text clustering based on lexical graph is proposed in this paper, which is a kind of term-based cluster method. The lexical graph is build with nodes representing words and edges representing their concurrent in text. The attribute of each node is text which the word occurs in. A cluster center is defined as node (word) with large degree in this graph, the center attributes (text occurs in) and its neighbors' are partitioned to one cluster whose description is the center node. This approach reduces drastically the dimensionality of the data and improves the synonymy extension ability. An experimental evaluation on Web documents as well as classical text documents on demonstrates that the proposed algorithms obtain clustering of comparable quality significantly more efficiently than K-Means and STC algorithms on the search results data set. Furthermore, this method provides an understandable description of the discovered clusters by their center.
Orientation calculation of words is the basis of orientation calculation on the large-scale text. Except some words, most of these word orientations are complex, and should be analysis in specific ...domain. The traditional algorithm of word orientation calculation relies mainly on the standard word set. The word orientation is calculated according to its semantic distance between words in the standard set. In this paper, a dynamic standard word set is build based on domain and part of speech information. The word orientation is calculated based on the corresponding standard set according to its domain and part of speech. The experiment results show that the proposed algorithm is reasonable. The domain and part of speech is useful for the orientation calculation.
Aims
To investigate the effects of the spatial distribution of rice root systems on dissolved CH
4
and CH
4
emissions and the CH
4
transport efficiency of aboveground plant parts in paddy fields.
...Methods
A two-year field and leaf cutting experiment was conducted on seven rice varieties, and we determined the dynamics of CH
4
emissions, root system traits and dissolved CH
4
concentrations in different soil layers, and the CH
4
transport efficiencies of the leaf and stem sheath.
Results
CH
4
emissions, the root distribution and the distribution of dissolved CH
4
concentration showed large discrepancies among the different rice varieties. Correlation analysis and structural equation modeling (SEM) revealed that CH
4
emissions had strong negative associations with root morphological traits (root dry weight, root area index and root volume density) and a clear positive correlation with dissolved CH
4
concentrations in the 0–20 cm soil layer. In addition, the root system had an indirect negative correlation with CH
4
emissions by influencing the dissolved CH
4
concentrations. Furthermore, root traits had strongly positive correlations with grain yield. In the aboveground parts, the CH
4
transport efficiencies of the leaf (20–70%) and stem sheath (30–80%) presented large differences among the different rice varieties, and CH
4
emissions exhibited significant positive correlations with leaf CH
4
transport efficiency and leaf dry weight.
Conclusions
Our results suggest that varieties with larger and deeper root distributions and lower leaf dry weight can decrease CH
4
emissions in paddy fields and maintain higher grain yield.
Rice paddy fields are important sources of atmospheric methane (CH4) and nitrous oxide (N2O). Dissolved organic matter (DOM) is one of the most reactive organic matter fractions in the soil. However, ...the relationships between greenhouse gas emissions and DOM properties associated with different rice varieties in paddy fields are unclear. Here, a two-year field experiment was conducted to investigate the relationships between DOM characteristics and microbial gene abundance on CH4 and N2O emissions in seven rice varieties. The dissolved organic carbon, dissolved sugar, and NH4-N and NO3-N contents were positively correlated with CH4 and N2O emissions, and dissolved phenol was negatively correlated with CH4 and N2O emissions. Fourier transform infrared (FTIR) and three-dimensional fluorescence (EEM) spectroscopy analysis further indicated that DOM includes more O-H and CO phenol and protein content, of which tryptophan-like and tyrosine-like protein materials were positively correlated with CH4 and N2O emissions. In addition, CH4 and N2O emissions were significantly correlated with microbial functional genes (mcrA, pmoA, AOA, AOB, nirS, and nosZ). The redundancy analysis indicated that dissolved organic carbon, dissolved sugar, NH4-N, NO3-N, and tyrosine-like and tryptophan-like proteins in the DOM were significantly correlated with soil microbial functional gene abundance, suggesting that DOM could regulate CH4 and N2O emissions by influencing microbial abundance. The rice variety with lower greenhouse gas emissions (YY 1540) had the highest yield. These results demonstrated that the differences in greenhouse gas emissions among different rice varieties were dependent on DOM properties and microbial abundance, providing a theoretical basis for mitigating greenhouse gas emissions in rice paddy fields.
•Significant differences in CH4 and N2O emissions were observed among rice varieties.•CH4 and N2O emissions significantly correlated to DOM properties.•DOM properties were strongly associated with microbial functional gene abundance.•DOM properties might affect CH4 and N2O emissions indirectly through the microbe.
Oyster polysaccharides (OPS) possess potent anti-inflammatory properties and mediate gut microbiome. The research aimed to investigate the beneficial effect of OPS on attenuating colitis. OPS ...administration decreased the disease activity index and suppressed the increase in colon length. Hematoxylin and eosin staining results displayed that OPS restored the DSS-induced histopathological damage. After oral administration of OPS, myeloperoxidase activity and pro-inflammatory cytokines (TNF-α) in colitis mice were inhibited, while IL-10 was elevated. Western blotting results revealed that OPS improved the expression of tight junction proteins (ZO-1, Claudin-4, and Occludin). Additionally, OPS stabilized the expression of hypoxia-inducible factor-1α (HIF-1α) and prevented the levels of bacterial endotoxin (lipopolysaccharides). OPS activated barrier-protective genes (intestinal trefoil factor) via mediating HIF-1α. These results indicated that OPS alleviated DSS-induced colitis by inhibiting inflammation and regulating HIF-1α. OPS would be a potential candidate to alleviate DSS-induced colitis.
•Oyster polysaccharides (OPS) alleviated inflammation response in colitis mice.•OPS improved the expression of tight junction protein and Muc2.•OPS recovered the gut barrier via stabilizing the expression of HIF-1α.
•gma-miR169c is widely expressed in soybean tissues and induced by polyethylene glycol, high salt levels, cold stress and abscisic acid.•Arabidopsis overexpressing gma-miR169c is more sensitive to ...drought stress, with reduced survival, accelerated leaf water loss, and shorter root length than the wild-type plants.•gma-miR169c negatively regulates the drought stress response by inhibiting the expression of the targets AtNFYA1 and AtNFYA5 and reducing the transcript levels of the stress response genes AtRD29A, AtRD22, AtGSTU25 and AtCOR15A.
The miR169 family, a large-scale microRNA gene family conserved in plants, is involved in stress responses, although how soybean miR169 functions in response to drought stress remains unclear. We show that gma-miR169c exerts a negative regulatory role in the response to drought stress by inhibiting the expression of its target gene, nuclear factor Y–A (NF-YA). A real-time RT-PCR analysis indicated that gma-miR169c is widely expressed in soybean tissues and induced by polyethylene glycol (PEG), high salt, cold stress and abscisic acid (ABA). Histochemical ß-glucuronidase (GUS) staining showed that the gma-miR169c promoter drives GUS reporter gene expression in various transgenic Arabidopsis tissues, and the stress-induced pattern was confirmed in transgenic Arabidopsis and transgenic soybean hairy roots. Arabidopsis overexpressing gma-miR169c is more sensitive to drought stress, with reduced survival, accelerated leaf water loss, and shorter root length than wild-type plants. We identified a precise cleavage site for 10 gma-miR169c targets and found reduced transcript levels of the AtNFYA1 and AtNFYA5 transcription factors in gma-miR169c-overexpressing Arabidopsis and reduced expression of the stress response genes AtRD29A, AtRD22, AtGSTU25 and AtCOR15A. These results indicate that gma-miR169c plays a negative regulatory role in drought stress and is a candidate miRNA for improving plant drought adaptation.
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