21 research outputs found

    An experimental study of the natural characteristics of the wheeled and the tracked self-propelled guns

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    With wheeled and tracked self-propelled guns as research object, the study carries out the experimental modal analysis by using traditional method of hammering and operational modal analysis method, and obtains low-order natural frequency of the guns, and thus lays the foundation for further research on the vibration characteristics of wheeled and tracked self-propelled guns. By contrasting the low-order natural characteristics of wheeled and tracked self-propelled guns, conclusions can draw as the following: the modal shapes (from low to high) of wheeled and tracked self-propelled guns are pitch, translation and roll; when the modal shapes are identical, the natural frequency of tracked self-propelled guns is greater than that of wheeled self-propelled guns, which accords with the test results of the gun’s suspension equivalent stiffness; for wheeled self-propelled guns, an accurate measure of the gun’s natural characteristics is feasible by either the traditional or the operational modal analysis method. When it comes to tracked self-propelled guns, the operational modal analysis method is more accurate

    Metabolome-Microbiome Responses of Growing Pigs Induced by Time-Restricted Feeding

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    Time-restricted feeding (TRF) mode is a potential strategy in improving the health and production of farm animals. However, the effect of TRF on microbiota and their metabolism in the large intestine of the host remains unclear. Therefore, the present study aimed to investigate the responses of microbiome and metabolome induced by TRF based on a growing-pig model. Twelve crossbred growing barrows were randomly allotted into two groups with six replicates (1 pig/pen), namely, the free-access feeding group (FA) and TRF group. Pigs in the FA group were fed free access while the TRF group were fed free access within a regular time three times per day at 07:00–08:00, 12:00–13:00, and 18:00–19:00, respectively. Results showed that the concentrations of NH4-N, putrescine, cadaverine, spermidine, spermine, total biogenic amines, isobutyrate, butyrate, isovalerate, total SCFA, and lactate were increased while the pH value in the colonic digesta and the concentration of acetate was decreased in the TRF group. The Shannon index was significantly increased in the TRF group; however, no significant effects were found in the Fisher index, Simpson index, ACE index, Chao1 index, and observed species between the two groups. In the TRF group, the relative abundances of Prevotella 1 and Eubacterium ruminantium group were significantly increased while the relative abundances of Clostridium sensu sticto 1, Lactobacillus, and Eubacterium coprostanoligenes group were decreased compared with the FA group. PLS-DA analysis revealed an obvious and regular variation between the FA and TRF groups, further pathway enrichment analysis showed that these differential features were mainly enriched in pyrimidine metabolism, nicotinate and nicotinamide metabolism, glycerolipid metabolism, and fructose and mannose metabolism. In addition, Pearson's correlation analysis indicated that the changes in the microbial genera were correlated with the colonic metabolites. In conclusion, these results together indicated that although the overall microbial composition in the colon was not changed, TRF induced the gradient changes of the nutrients and metabolites which were correlated with certain microbial genera including Lactobacillus, Eubacterium_ruminantium group, Eubacterium coprostanoligenes group, Prevotella 1, and Clostridium sensu sticto 1. However, more studies are needed to understand the impacts of TRF on the health and metabolism of growing pigs

    Suitable nitrogen fertilizer application drives the endosperm development and starch synthesis to improve the physicochemical properties of common buckwheat grain

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    The effects of nitrogen (N) fertilizer on endosperm development, starch component, key enzyme activity and grain quality of common buckwheat were investigated in this study. The results showed that N fertilization significantly enhanced the number and area of endosperm cells, and significant increases were also observed in the contents of amylose, amylopectin and total starch. With increasing N level, the activities of key enzyme significantly increased showing the maximum under the N2 level (180 kg N ha-1), and then decreased under high N level. As N level increased, the ash, crude protein and amylose content varied from 1.36 to 2.25%, from 7.99 to 15.84% and from 22.69 to 27.64%, respectively. The gelatinization enthalpy significantly increased with the range of 3.46-5.66 J/g, while no change was found in crystalline structure of common buckwheat flour. These results indicated that appropriate N application could effectively improve the endosperm development, starch synthesis and accumulation, and grain properties of common buckwheat, with the best effect under the level of 180 kg N ha-1

    Changes in the structural and physicochemical characterization of pea starch modified by Bacillus-produced α-amylase

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    In this study, changes in structural and physicochemical properties of pea starch treated with Bacillus-produced α-amylase were determined. The results showed that enzymatically modified pea starch had lower amylose content and granule size but higher branching degree and relative crystallinity. After enzyme hydrolysis, the distribution of A and B1 chains slightly decreased, while the distribution of B2 and B3 chains increased lightly. Enzymatic hydrolysis preferentially occurred in the amorphous region and cannot change the crystalline structure of pea starch. Moreover, pea starch showed lower light transmittance, peak viscosity, breakdown viscosity, pasting temperature, shear viscosity, storage modulus and loss modulus, while the oil adsorption capacity and gelatinization enthalpy significantly increased with increasing α-amylase hydrolysis time. Correlation analysis indicated that α-amylase hydrolysis had different effects on different pea varieties. This research could provide ideas for exploring new applications for enzymatically modified pea starch in food industry

    Relationship between nitrogen fertilizer and structural, pasting and rheological properties on common buckwheat starch

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    Nitrogen is an essential element for the yield and quality of grain. In this study, the structural and physicochemical properties of two common buckwheat varieties under four nitrogen levels (0, 90, 180, 270 kg N ha(-1)) at one location in two years were investigated. With increasing nitrogen level, the contents of moisture and amylose decreased but the contents of ash and crude protein increased. Excessive nitrogen application significantly increased the granule size, but reduced the light transmittance, water solubility, swelling power, absorption of water and oil. All the samples showed a typical A - type pattern, while high relative crystallinity and low order degree were observed under high nitrogen level. The samples under high nitrogen level had lower textural properties, pasting properties and rheological properties but higher pasting temperature and gelatinization enthalpy. These results indicated that nitrogen fertilizer significantly affected the structural and physicochemical properties of common buckwheat starch

    The Laccase Family Gene <i>CsLAC37</i> Participates in Resistance to <i>Colletotrichum gloeosporioides</i> Infection in Tea Plants

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    Fungal attacks have become a major obstacle in tea plantations. Colletotrichum gloeosporioides is one of the most devastating fungal pathogens in tea plantations that can severely affect tea yield and quality. However, the molecular mechanism of resistance genes involved in anthracnose is still largely unknown in tea plants. Here, we found that the laccase gene CsLAC37 was involved in the response to fungal infection based on a transcriptome analysis. The full-length CDS of CsLAC37 was cloned, and its protein sequence had the closest relationship with the Arabidopsis AtLAC15 protein compared to other AtLACs. Tissue-specific expression analysis showed that CsLAC37 had higher expression levels in mature leaves and stems than in the other tissues. Subcellular localization showed that the CsLAC37 protein was predominantly localized in the cell membrane. The expression levels of CsLAC37 were upregulated at different time points under cold, salt, SA, and ABA treatments. qRT-PCR confirmed that CsLAC37 responded to both Pestalotiopsis-like species and C. gloeosporioides infections. Functional validation showed that the hydrogen peroxide (H2O2) content increased significantly, and POD activity decreased in leaves after antisense oligonucleotide (AsODN) treatment compared to the controls. The results demonstrated that CsLAC37 may play an important role in resistance to anthracnose, and the findings provide a theoretical foundation for molecular breeding of tea varieties with resistance to fungal diseases

    Structural and physicochemical properties of pea starch affected by germination treatment

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    Two pea varieties were used to investigate the changes in the structural and physicochemical properties of pea starch during germination. The results showed that there were more obvious crimples on the surface of the germinated pea starch granules than native starch. Germination treatment led to significant increases in the amylose content and granule size distribution, while volume proportion of germinated pea starch significantly decreased. All the pea starches showed a typical C-type crystalline structure but the relative crystallinity slightly decreased during germination. Compared with the native starches, the light transmittance and absorption capacities of water and oil all firstly increased and then decreased with the increase of germination time. Moreover, there were obvious increases in the peak viscosity, trough viscosity and final viscosity, while the pasting temperature significantly decreased as germination prolonged to 4 d. The gelatinization temperature of pea starch firstly decreased and then increased during germination, while germinated pea starch showed higher gelatinization enthalpy than that of native starch. In conclusion, the structural and physicochemical properties of pea starch could be significantly affected under germination treatment, which may provide a theoretical basis to promote the utilization of germinated pea starch in the food industry

    Soil properties, bacterial and fungal community compositions and the key factors after 5-year continuous monocropping of three minor crops.

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    Minor grain crops are widely cultivated in northwest China and played important roles in local economic. Soil microbes play a central role in ecological function and biological stability and related to soil quality. In order to uncover the soil microbial composition differences and the factors under 5-year continuous monocropping of three minor crops (Proso millet, Common bean and Common buckwheat) in Guan-Zhong Plain, six soil nutrimental parameters, soil pH, soil moisture content, and four soil enzyme activities were analyzed and soil microbial composition were sequenced. The results showed that after 5-years of continuous monocropping, different cover crops influenced most of soil physicochemical properties, expect soil moisture content (P < 0.05), the available nutrients were significant higher in proso millet soil, and the pH was significantly higher in common buckwheat soil. soil ALP, catalase and urease activities were significantly different between soils (P< 0.01), in which soil catalase activities were significantly lower and soil ALP and urease activities were significantly higher than that of proso millet and common buckwheat. A total of 171439 sequences, 9468 OTUs and 29 phylum for bacteria, 128920 sequences, 544 OTUs and 27 phylum for fungi were obtained. In addition, no significantly difference obtained in diversity and richness between soils (P < 0.05). According to relative abundance, Proteobacteria, Chloroflexi, Gemmatimonadetes and Acidobacteria were the dominant bacterial phylum in all samples, moreover, the relative abundance of Caldiserica was significantly different between soils (P < 0.05). Ascomycota (79.04%-90.21%) was dominant phylum in fungal community and phylum Phragmoplastophyta (P < 0.01) and Glomeromycota (P < 0.05) were significantly different between soils. Redundancy analysis indicated that available nutrients Nitrogen and Potassium are the strongest predictors in both bacterial and fungal community. In conclusion, different cover crops influenced soil nutrient properties, soil pH and soil microbial composition, and continuous monocropping decreased soil fertility condition. Moreover, Common bean and Common buckwheat were more sensitive to monocropping treatment

    A Buckwheat (Fagopyrum esculentum) DRE-Binding Transcription Factor Gene, FeDREB1, Enhances Freezing and Drought Tolerance of Transgenic Arabidopsis

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    CBF/DREB transcription factors play essential roles in plant stress signaling transduction pathway. We isolated and identified a CBF/DREB homologous gene, FeDREB1, from Fagopyrum esculentum. Protein sequence alignment and phylogenetic analyses revealed that the FeDREB1 was grouped into the DREB (A-1) lineage. Moreover, subcellular localization observations suggested that FeDREB1 localizes in the nucleus. Yeast one-hybrid assays showed that FeDREB1 protein specifically binds to the DRE sequence and could activate the expression of reporter genes in yeast. These results further suggested that the FeRDEB1 protein was a CBF/DREB transcription factor. Expression analysis revealed that the transcript levels of the FeRDEB1 gene increased rapidly following low-/high-temperature treatment, drought stress, and exogenous ABA treatment. Over-expression of the FeDREB1 gene significantly enhanced the drought and freezing tolerance of transgenic Arabidopsis but resulted in its growth retardation. Moreover, the transgenic Arabidopsis lines were also highly sensitive to ABA application. Digital gene expression profiling (DGE) analysis indicated that increased transcript levels of many ABA-independent/-dependent stress-responsive genes in 35S::FeRDEB1 transgenic Arabidopsis, revealing that the FeDREB1 may participate in an ABA-dependent/-independent pathways

    Novel lightweight open-cell polypropylene foams for filtering hazardous materials

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    Owing to the problems existing in traditional technologies for preparing commercial cellulose acetate (CA) cigarette filters, such as complex processing and chemical solution usage, novel lightweight polypropylene (PP) foams with similar geometries but different porous structures were designed and successfully prepared as filters for potentially hazardous materials via supercritical CO2 (scCO(2)) extrusion foaming technology without the use of any harmful chemical reagents and the problems of floating micro-nano fibers. Interestingly, the results showed that the PP foams with a flower-like/bamboo-like foamed structure not only possess modest draw resistance of 2625 Pa to maintain the smoking mouthfeel, but also show modest filtering performance, as some of the smoke constituents such as tar, nicotine, and benzo[a]pyrene (B[a]P) of the sample are similar to that of the commercial CA cigarette filters, suggesting its excellent potential as the next-generation cigarette filters. Moreover, the formation mechanism of different foam structures as well as the mechanism of the cigarette smoke transport in such PP foams is discussed
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