Wyniki wyszukiwania - Biblioteka Nauki

1

Effects of quinestrol and levonorgestrel on prolactin serum concentration in lactating Mongolian gerbils (Meriones unguiculatus) and reproductive parameters of their offspring

100%

Lv X. , Guo Y. , Shi D.

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nr 3

2

Microwave irradiation enhances the germination rate of tartary buckwheat and content of some compounds in its sprouts

100%

Wang S. , Wang J. , Guo Y.

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tom 68

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nr 3

EN

Tartary buckwheat (Fagopyrum tataricum) seeds were irradiated with microwaves at various power levels of 200, 400, 600 and 800 W for 10 or 30 s. The irradiated grains were germinated for 3, 5, and 7 days and harvested. The germination rate of the tartary buckwheat seeds and contents of some compounds in the sprouts were investigated. The results showed that the exposure to 600 W microwaves for 10 s resulted in the highest fi nal germination rate after 7 days of germination, which was 2 times that of the control. The exposure of seeds to 800 W for 30 s showed the lowest germination rate (approximately 10%), which decreased by 87% compared with the control (p<0.05). The exposure at 600 W for 30 s stimulated the total flavones content, reduced the sugar and soluble protein contents, and increased the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. The highest free amino acid content (11 mg/g) was observed in 5-day sprouts exposed to 800 W for 10 s. Moreover, the microwave treatment had a positive effect on the catalase (CAT) and superoxide dismutase (SOD) activity.

3

3D Measurement and Modelling of Magnetic Properties of Soft Magnetic Composite

100%

Zhu J. , Lin Z. , Guo Y. , Huang Y.

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tom R. 85, nr 1

11-15

EN

The soft magnetic composite (SMC) is a new type of soft magnetic material made of insulated iron powders. Its special characteristics could enable the development of low cost high performance electrical machines. This paper presents the measurement and modelling of magnetic properties of SMC under 3D magnetizations. Detailed descriptions of the 3D magnetic property tester, principle of measurement, core loss models, and experimental results are included and discussed.

PL

Magnetycznie miękkie kompozyty (soft magnetic composites – SMC) są nowym rodzajem magnetycznie miękkich materiałów wykonanych z elektrycznie izolowanych cząsteczek proszku żelaza. Specjalne charakterystyki takich materiałów mogą umożliwić rozwój tanich i wydajnych maszyn elektrycznych. Artykuł prezentuje pomiary i modelowanie własności magnetycznych SMC w warunkach przemagnesowania 3D. Podano dokładny opis użytej techniki pomiarowej, modelu i wyników pomiarowych.

4

The growth morphology of ZnO hexangular tubes synthesized by the solvothermal method

100%

Li Y. , Liu X. , Zou Y. , Guo Y.

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tom Vol. 27, No. 1

187--192

EN

A novel hexangular tube structure of ZnO has been successfully synthesized via the solvo-thermal method, using Zn(NO3)2o6H2O and NaOH as starting materials. The results showed that the supersaturation near the surface of ZnO crystal is higher than that inside the crystal, which leads to a preferential growth along c-axis of the side surface. The strain between the surface and the bulk of ZnO rods drives ZnO rods into tubular structure. The spectroscopic results show that ZnO tubes possess the wurtzite structure. Three emission peaks have been detected, a violet peak at about 399.9 nm, a blue emission at about 448.5 nm and a green emission at about 549.8 nm.

5

Variations of cuticular wax in mulberry trees and their effects on gas exchange and post-harvest water loss

88%

Ni Y. , Sun Z. , Huang X. , Huang C. , Guo Y.

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tom 37

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nr 06

EN

Though mulberry (Morus alba) tree shows great adaptations to various climate conditions, their leaf water status and photosynthesis are sensitive to climate changes. In the current study, seven widely planted mulberry cultivars in Chongqing, Southwest China, were selected to analyze leaf cuticular wax characteristics, gas exchange index, post-harvest leaf water status and their relationships, aiming to provide new theory in screening high resistant mulberry cultivars. Mulberry trees formed rounded cap-type idioblasts on the adaxial leaf surface. Film-like waxes and granule-type wax crystals covered leaf surfaces, varying in crystal density among cultivars. The stomatal aperture on the abaxial surface of cultivars with high wax amount was smaller than that of cultivars with low wax amount. The amount of total wax was negatively correlated with the net photosynthetic rate (PN), transpiration rate (E) and stomatal conductance (gs) and positively correlated with the moisture retention capacity. It suggested that both cuticular wax and stomatal factor might be involved in regulating water loss in mulberry leaves under field conditions. The variability in moisture retention capacity and cuticular wax characteristics might be important in evaluating and screening mulberry cultivars for increasing silk quality and silkworm productivity.

6

Core-shell SiO2/Ag composite spheres: synthesis, characterization and photocatalytic properties

88%

Wu Z. G. , Jia Y. R. , Wang J. , Guo Y. , Gao J. F.

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tom Vol. 34, No. 4

806--810

EN

Core-shell SiO2/Ag composite spheres with dense, complete and nanoscaled silver shell were prepared by using a novel facile chemical reduction method without surface modification of silica at room temperature. The core-shell composites were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), UV-Vis spectroscopy and energy dispersive X-ray spectroscopy (EDX). The photocatalytic properties towards the degradation of methyl orange (Mo) of the prepared SiO2//Ag composites were also tested. The studies showed that the surface of SiO2/ microspheres was homogeneously and completely covered by Ag nanoparticles and the composite exhibited excellent photocatalytic activities. The possible reaction mechanisms for the formation of the silica-silver core-shell spheres were also discussed in this paper.

7

Effects of dietary fish oil on NF kappa B gene expression and related signaling in spleen of chickens stimulated with lipopolysaccharide

76%

Yang X. , He X. , Zhang B. , Yang Y. , Yuan J. , Guo Y.

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nr 2

EN

The study was conducted to investigate the effects of fish oil and maize oil on nuclear factor kappa B (NFκB) gene expression and the downstream pathways of intracellular signaling in spleen of chickens after lipopolysaccharide (LPS) stimulation. Two hundred eighty eight chickens were assigned in a 2×2 factorial design. Factors were dietary fat type (4.5% maize oil or 4.5% fish oil) and immunological stimulation (LPS or saline). LPS increased levels of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and arachidonic acid (AA) of spleen in chickens after the second LPS stimulation on 28 d of age. Fish oil alleviated the increase of EPA and DHA in spleen of chickens after LPS stimulation at 27 d of age. Fish oil supplementation decreased prostaglandin 2 (PGE2) production and the activity of cyclooxygenase 2 (COX2) after LPS stimulation. LPS stimulation increased the activity of phospholipase C (PLC) in spleen of chickens. And fish oil inhibited activity of PLC in spleen of chickens stimulated by LPS. Meanwhile fish oil decreased the production of inositol triphosphate (IP3) in spleen of chickens stimulated by LPS. Fish oil alleviated the mRNA abundance elevation of nuclear factor kappa B (NFκB) after LPS stimulation. These results showed that fish oil down-regulated the production of IP3 and PGE2 through inhibiting the activity of PLC and COX2 in spleen of chickens, respectively. The results of NFκB gene expression suggested fish oil might alleviate immune stress at the level of transcription.

8

Fault risk assessment of underwater vehicle steering system based on virtual prototyping and Monte Carlo simulation

76%

He D. , Hu N. , Hu L. , Chen L. , Guo Y. , Chen S.

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nr 3

EN

Assessing the risks of steering system faults in underwater vehicles is a human-machine-environment (HME) systematic safety field that studies faults in the steering system itself, the driver’s human reliability (HR) and various environmental conditions. This paper proposed a fault risk assessment method for an underwater vehicle steering system based on virtual prototyping and Monte Carlo simulation. A virtual steering system prototype was established and validated to rectify a lack of historic fault data. Fault injection and simulation were conducted to acquire fault simulation data. A Monte Carlo simulation was adopted that integrated randomness due to the human operator and environment. Randomness and uncertainty of the human, machine and environment were integrated in the method to obtain a probabilistic risk indicator. To verify the proposed method, a case of stuck rudder fault (SRF) risk assessment was studied. This method may provide a novel solution for fault risk assessment of a vehicle or other general HME system

9

Adaptative strategy of leaf traits to drought conditions: Quercus aliena var. acuteserrata forest (The Qinling Mts. China)

76%

Wang M. , Wan P. , Chai Y. , Guo Y. , Zhang X. , Yue M.

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tom 63

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nr 1

EN

In a climax community where all species are sharing relatively similar and stable habitat, there are differences in leaf traits between deciduous trees and shrubs and dominant species and companion species, especially in leaf lifespan (LLs). What are the differences of relationships among leaf traits between deciduous trees and shrubs? What are the mechanisms of this phenomenon? Here, we presented a one-year observation and recorded the LLs followed a modified method in a Quercus aliena var. acuteserrata forest in the north slope of the Qinling Mountains, China. We found that (i) Different species in the same stand performed quite differently in their LLs (P <0.005). Average LLs of shrubs was slightly longer (P = 0.05) than that of deciduous trees. (ii) LLs showed a significant negative correlation with specific leaf area (SLA) and leaf nitrogen content (LNC) (P <0.05) in deciduous trees, however, a significant positive correlation with LNC and leaf carbon content (LCC) (P <0.05) was detected in shrubs. (iii) The comparison of the traits between dominant and companion species in arbor layer and shrub layer showed that there was no significant difference in LLs, LCC and LNC, except SLA in arbor layer. Our study indicated that the amount of light, at the community scale, might be a main factor determining the LLs of wood plants in deciduous forest. The difference between trees and shrubs in relationships among leaf traits suggests that deciduous trees and shrubs may take different strategies to adapt to the environment. SLA is likely to be a marker trait to distinguish dominant and companion species in arbor layer of deciduous broad leaved forest.

10

Transcriptional analyses of endometrial caruncles in sheep with in vivo / in vitro produced embryos during the peri-implantation period

76%

Xing K. , Qi X. , Ni H. , Wang X. , Guo Y. , Sheng X.

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tom 19

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nr 4

11

Expression and localization of cannabinoid receptor 1 in rats’ brain treated with acute and repeated morphine

76%

Jin L. , Pan L. , Guo Y. , Zheng Y. , Nie Z. , Zhu R.

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nr 3

EN

Morphine induces adaptive changes in gene expression throughout the reward circuitry of brain. Recent research has proven the functional interactions between opioid and endogenous cannabinoid system in the central nervous system (CNS). The cannabinoid receptor 1 (CBj-R) is one of the receptors that mediate the actions of cannabinoids and endocannabinoids in the CNS. Here, we investigated the expression of CBrR in mRNA and protein levels in the brains of rats treated with acute and repeated morphine. Three groups of rats received intraperitoneal injections (ip injections) of saline, acute morphine (10 mg/ kg) and repeated morphine (10 mg/kg, twice daily for 12 consecutive days), and the mRNA levels and protein expressions of CB1-R were examined. RT-PCR and western blot analyses supported that both mRNA and protein levels of CB1-R in cortex, cerebellum and hippocampus were increased by repeated morphine treatment. However, the mRNA level in cerebellum was down-regulated only after acute morphine treatment and would returned to basal levels later. We used immunohistochemistry techniques to determine the functional expression of CB1-R in morphine treated rat's brain. Enzyme- Linked Immunosorbent Assay (ELISA) revealed the significant increase of cytokine (IL-ip, IL-6) levels in the repeated morphine treatment rats' cortex and hippocampus regions, which are both addiction-related brain areas. In addition, the results from RT-PCR and western blot assay indicated that the expression of CB1-R was directly increased by morphine treatment in vitro. All the results indicated that the CB1-R expression could be changed by morphine exposure and it might be involved in neural immune function, which provided a potential target for neurogenic disease treatment.

12

Adaptative strategy of leaf traits to drought conditions: Quercus aliena var. acuteserrata forest (The Qinling Mts. China)

76%

Wang M. , Wan P. , Chai Y. , Guo Y. , Zhang X. , Yue M.

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tom Vol. 63, nr 1

77--87

EN

In a climax community where all species are sharing relatively similar and stable habitat, there are differences in leaf traits between deciduous trees and shrubs and dominant species and companion species, especially in leaf lifespan (LLs). What are the differences of relationships among leaf traits between deciduous trees and shrubs? What are the mechanisms of this phenomenon? Here, we presented a one-year observation and recorded the LLs followed a modified method in a Quercus aliena var. acuteserrata forest in the north slope of the Qinling Mountains, China. We found that (i) Different species in the same stand performed quite differently in their LLs (P <0.005). Average LLs of shrubs was slightly longer (P = 0.05) than that of deciduous trees. (ii) LLs showed a significant negative correlation with specific leaf area (SLA) and leaf nitrogen content (LNC) (P <0.05) in deciduous trees, however, a significant positive correlation with LNC and leaf carbon content (LCC) (P <0.05) was detected in shrubs. (iii) The comparison of the traits between dominant and companion species in arbor layer and shrub layer showed that there was no significant difference in LLs, LCC and LNC, except SLA in arbor layer. Our study indicated that the amount of light, at the community scale, might be a main factor determining the LLs of wood plants in deciduous forest. The difference between trees and shrubs in relationships among leaf traits suggests that deciduous trees and shrubs may take different strategies to adapt to the environment. SLA is likely to be a marker trait to distinguish dominant and companion species in arbor layer of deciduous broad leaved forest

13

UV-Vis spectroscopic detection coupled with chemometrics for the measurement of mixed organic acids in water samples enriched by radial electric focusing solid phase extraction

76%

Guo Y. , Liu X. , Liu J. , Bian X. , Zhang Q. , Pan J. , Wan D.

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2018

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tom Vol. 25, nr 2

317--329

EN

Due to the difficulty of detecting traces of organic acid mixture in an aqueous sample and the complexity of resolving UV-Vis spectra effectively, a combinatory method based on a self-made radical electric focusing solid phase extraction (REFSPE) device, UV-Vis detection and partial least squares (PLS) calculation is proposed here. In this study, REFSPE was used to enhance the extraction process of analytes between the aqueous phase and the membrane phase to enrich the trace of mixed organic acid efficiently. Then, the analytes, which were eluted from the adsorption film by ethanol with the assistance of an ultrasonic cleaning machine, were detected with UV-Vis spectrophotometry. After that, the PLS method was introduced to solve the problem of overlapping peaks in UV-Vis spectra of mixed substances and to quantify each compound. The linearly dependent coefficients between the predicted value of the model and the actual concentration of the sample were all higher than 0.99. The limit values of detection for benzoic acid, phthalic acid and p-toluene sulfonic acid were found at 9.9 μg/L, 12.2 μg/L and 13.8 μg/L with the relative recovery values between 84.8% and 117.9%. The RSD (n = 20) values of each component are 1.17%, 1.11% and 0.86%, respectively. Therefore, the proposed combined method can determine traces of complex materials in an aqueous sample efficiently and has wonderful potential applications.

14

Exosome-derived uterine microRNAs isolated from cows with endometritis impede blastocyst development

76%

Wang X. , Tian F. , Chen C. , Feng Y. , Sheng X. , Guo Y. , Ni H.

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tom 19

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nr 2

15

Methyl jasmonate-induced accumulation of metabolites and transcriptional responses involved in triterpene biosynthesis in Siraitia grosvenorii fruit at different growing stages

76%

Zhang K. , Luo Z. , Guo Y. , Mo C. , Tu D. , Ma X. , Bai L.

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nr 3

EN

The cucurbitane-type triterpenoid glycosides, mogrosides, are the main active components of Siraitia grosvenorii fruit. Squalene and cucurbitadienol are among the intermediates of the biosynthetic pathway for the formation of cucurbitane-type triterpenoid backbones of mogrosides. It is recognized that the exogenous application of methyl jasmonate (MeJA) increases the accumulation of secondary metabolites in various plant species. Here, the effect of MeJA (50, 200, and 500 μM) on the accumulation of squalene and cucurbitadienol in the fruits of S. grosvenorii at 10, 20, and 30 days after flowering (DAF) was tested for the first time. Since mogroside II E is the main cucurbitane-type triterpenoid present at this time, its concentration was also determined. The results show that MeJA can indeed promote squalene and cucurbitadienol accumulation, the application of 500 μM MeJA at 30 DAF being optimal. The concentration of squalene and cucurbitadienol increased up to 0.43 and 4.71 μg/g dry weight (DW), respectively, both of which were 1.2-fold greater than that of the control. The content of mogroside II E increased by 15% over the untreated group. We subsequently analyzed the expression of key genes involved in the mogroside biosynthetic pathway, including the 3-hydroxy-3-methylglutaryl-coenzyme A reductase gene (SgHMGR), squalene synthetase gene (SgSQS), cucurbitadienol synthase gene (SgCS), and cytochrome P450 (SgCYP450) with quantitative real-time PCR. The results showed that transcriptional levels of these genes were upregulated following the treatment described above. Additionally, their responses in the presence of MeJA was related to the concentration and timing of MeJA treatment.

16

Development of an indirect ELISA based on glycoprotein B gene for detecting of Feline herpesvirus type 1

71%

Tan Y. , Dong G. , Niu J. , Guo Y. , Yi S. , Sun M. , Wang K. , Hu G. , Tan Y. , Dong G. , Niu J. , Guo Y. , Yi S. , Sun M. , Wang K. , Hu G.

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17

A genome-wide association study identifies genomic loci associated with backfat thickness, carcass weight, and body weight in two commercial pig populations

63%

Guo Y. , Qui H. , Xiao S. , Wu Z. , Yang M. , Yang J. , Ren J. , Huang L.

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nr 4

18

An integrated analysis of testis miRNA and mRNA transcriptome reveals important functional miRNA-targets in reproduction traits of roosters

63%

Xing K. , Gao M. , Li X. , Feng Y. , Ge Y. , Qi X. , Wang X. , Ni H. , Guo Y. , Sheng X.

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tom 20

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nr 3

19

Morphological, physiological and genetic analyses of an upward-curling leaf mutant in Brassica napus L.

63%

Faisal S. , Guo Y. , Du C. , Zhang D. , Lv J. , Channa S. A. , Qu G. , Hu S.

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tom 42

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nr 04