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1

Study of the force and deformation characteristics of subsea mudmat-pile hybrid foundations

100%
Kong D., Deng M., Liu Y., Tan X.
Polish Maritime Research
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2018
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tom 25
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nr Special Issue S3
To study the force and deformation characteristics of subsea mudmat-pile hybrid foundations under different combined loads, a project at a water depth of 200 m in the South China Sea was studied. A numerical model of a subsea mudmat-pile hybrid foundation is developed using the numerical simulation software FLAC3D. The settlement of the seabed soil, the bending moments of the mudmat, and the displacements and bending moments along the pile shaft under different load combinations, including vertical load and horizontal load, vertical load and bending moment, and horizontal load and bending moment load, are analyzed. The results indicate that settlement of the seabed soil is reduced by the presence of piles. The settlement of the mudmat is reduced by the presence of piles. Different degrees of inclination occur along the pile shaft. The angle of inclination of pile No. 1 is greater than that of pile No. 2. The dip directions of piles No. 1 and No. 2 are identical under the vertical load and bending moment and are opposite to those under the other combined loads. The piles that are located at the junctions between the mudmat and the tops of the piles are easily destroyed
2

Effects of iron and root zone pH on growth and physiological responses of paper birch (Betula papyrifera), trembling aspen (Populus tremuloides) and red-osier dogwood (Cornus stolonifera) seedlings in a split-root hydroponic system

100%
Xu F., Tan X., Zhang W.-Q., Zwiazek J. J.
Acta Physiologiae Plantarum
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2019
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tom 41
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nr 08
Iron deficiency that is induced by high soil pH is a major factor affecting plant growth in calcareous soils and in some areas that have been reclaimed following industrial activities. Since the effects of high soil pH commonly involve Fe deficiency, in this study, we examined whether Fe provided to part of the root system exposed to low pH would alleviate high pH stress in paper birch (Betula papyrifera), trembling aspen (Populus tremuloides) and red-osier dogwood (Cornus stolonifera) seedlings. The plants were grown in a controlled environment growth room in mineral nutrient solution at pH 5 and 9 and provided with either 0 or 40 µM Fe in a split-root system for 8 weeks. At the end of the treatments, plant dry weights, net photosynthesis, transpiration rates, root ferric-chelate reductase activity, and leaf chlorophyll concentrations were measured, and elemental analyses were carried out in young leaves. The results demonstrated high root zone pH affected Fe, P and Zn concentrations in young leaves. In the three considered species, plants with part of their root system exposed to pH 5 had higher dry weights, net photosynthesis, and transpiration rates compared with the plants with the whole root system immersed in pH 9 solution. High root zone pH reduced photosynthesis, transpiration rates, leaf chlorophyll concentrations and the uptake of Fe, P, and Zn in plants. Partial exposure of the root system to low pH and Fe supply reduced leaf chlorosis and partly alleviated the high pH stress in the studied plants by improving Fe uptake, but did not alleviate root growth reductions.
3

Variations and relationships of stable isotope composition in size-fractionated particulate organic matter

100%
Zeng Q., Kong F., Tan X., Wu X.
Polish Journal of Environmental Studies
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2010
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tom 19
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nr 6
4

Morphological and biomass characteristic acclimation of trident maple (Acer buergerianum Miq.) in response to light and water stress

76%
Guo X., Guo W., Luo Y., Tan X., Du N., Wang R.
Acta Physiologiae Plantarum
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2013
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tom 35
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nr 04
Acer buergerianum Miq. (Trident maple) is a native species of China with a large distribution, but exist in small population. Water and light are two important factors limiting plant growth and are crucial in the framework of forest regeneration. However, there is no consensus on how shade interacts with drought. Four hypotheses in the recent literature variously predict that shade will have a stronger, weaker or equal impact on seedlings under drought stress. This study investigated the interactive responses of A. buergerianum to light and water focusing on seedling growth, leaf morphology and biomass partitioning by performing a growth experiment in pots with different water supply regimes [15, 35, 55, 75, 95 % of field capacity (FC)] combined with two light regimes (10 and 66 % of full sunlight). After 123 days treatment, the results showed that shade greatly reduced growth and biomass, in contrast enhancing the amount of chlorophyll, the amount of water in the leaves, and the specific leaf area. Drought reduced growth, biomass, and the bulk of the leaves. Most leaf traits and biomass characteristics had strong interactions in their responses to light and water treatments. Allometric analysis revealed that water and light had no effects on root to shoot ratios, main root to lateral root ratios, and root mass ratios. Shade alleviated the negative impact of drought. A. buergerianum successfully adapted to the various light and water conditions. We recommend a water supply above 15 % FC to keep the seedlings vigorous, under both sunlight conditions.
5

Role of aquaporins in plant responses to root hypoxia

76%
Zwiazek J. J., Tan X., Xu H., Khan S., Equiza M. A., Lee S. H., Vaziriyeganeh M.
Acta Physiologiae Plantarum
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2018
|
tom 40
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nr 11-11th International Conference Plant Functioning under Environmental Stress...
6
Content available remote

Regulation of the expression of cyclooxygenases and production of prostaglandin I2 and E2 in human coronary artery endothelial cells by curcumin

76%
Tan X., Poulose E. M., Raveendran V. V., Zhu B.-T., Stechschulte D. J., Dileepan K. N.
Journal of Physiology and Pharmacology
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2011
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tom 62
|
nr 1
Curcumin regulates prostaglandin (PG) synthesis in a variety of cells. PGE2 and PGI2 are generated from arachidonic acid (AA) by cyclooxygenases 1 and 2 (COX-1 and COX-2) and the synthase (PGES and PGI2S) pathways. This study evaluates the in vitro effect of curcumin on the expression of COX-1, COX-2, PGI2S and microsomal PGES-1 (mPGES-1), and the production of PGE2 and PGI2 in human coronary artery endothelial cells (HCAEC). HCAEC monolayers were incubated with curcumin and the expression of mRNA, protein and the production of PGI2 and PGE2 were quantified. Incubation of HCAEC with curcumin led to a time and concentration-dependent increases in COX-2 mRNA with a small but significant decrease in COX-1 mRNA expression. Curcumin also stimulated the expression of PGI2S and mPGES-1 mRNA. Although curcumin stimulated COX-2, PGI2S and mPGES-1 gene expression, it failed to increase PGI2 or PGE2 production. Interestingly, supplementation of the culture medium with AA increased prostanoid production by both quiescent and curcumin-treated cells. However, in comparison to the quiescent cells, the prostanoid production by curcumin-treated cells was markedly enhanced as AA concentrations in the medium were increased, and the enhanced prostanoid production was blocked by the presence of COX-2 specific inhibitor. Taken together, these results suggest that curcumin regulates prostanoid homeostasis in HCAEC by modulating multiple steps including the expression of COX-1, COX-2, PGI2S and mPGES-1.
7
Content available remote

Increased aortic atherosclerotic plaque development in female apolipoprotein E-null mice is associated with elevated thromboxane A2 and decreased prostacyclin production

76%
Smith D. D., Tan X., Tawfik O., Milne G., Stechschulte D. J., Dileepan K. N.
Journal of Physiology and Pharmacology
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2010
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tom 61
|
nr 3
309-316
The production of thromboxane A2 (TXA2) and prostacyclin (prostaglandin I2, PGI2) is known to be increased in patients with atherosclerosis. In this study, we evaluated the influence of gender on TXA2 and PGI2 production, and their association with the progression of atherosclerosis in apolipoprotein E-null (ApoE-/-) mice maintained on a high fat diet for 3 months. En face analyses of aortas showed marked increases in plaque formation in female ApoE-/- mice. Quantification of the hematoxylin/eosin (H&E) stained cross sections of the aortic arch revealed 3 to 4-fold higher plaque thickness in female ApoE-/- mice. Analyses of 24-hours urine samples for 11-dehydro TXB2 and 2, 3-dinor-6-keto PGF1alpha indicated that female ApoE-/- mice produce up to 15-fold more TXA2 and 50% less PGI2 than the age matched males. Interestingly, the serum cholesterol levels in ApoE-/- females were 20% lower than males on the high fat regimen. No gender-associated changes in the number of T lymphocytes, mast cells and macrophages were evident in the lesion areas of ApoE-/- mice. The results suggest that the markedly elevated TXA2 production and reduced PGI2 production are gender-related proatherogenic risk factors in female ApoE-/- mice.
8

Beta-carotene as a dietary factor affecting expression of genes connected with carotenoid, vitamin A and lipid metabolism in the subcutaneous and omental adipose tissue of beef cattle

64%
Wei C., Tan X., Liu G., Wan F., Zhao H., Zhang C., You W., Liu X., Zhang X., Jin Q.
Journal of Animal and Feed Sciences
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2020
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tom 29
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nr 1
9

Differential gene expression of bovine intramuscular and subcutaneous preadipocytes during differentiation

64%
Liu X., Zang K., Song E., Ling Z., Tan X., Liu G., Cheng H., Wan F.
Animal Science Papers and Reports
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2012
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tom 30
|
nr 2
The study suggests that Sirtuin 1 (SIRT1) may play an important role in the development of bovine adipose tissue in vivo. To investigate the differential mRNA expression between bovine intramuscular (IM) preadipocytes (BIPs) and subcutaneous (SC) preadipocytes (BSPs), conventional collagenasebased procedures were modified to harvest preadipocytes from the longissimus dorsi muscle and SC adipose tissue of Luxi cattle, respectively. The time-spatial expression of SIRT1 and associated genes, such as forkhead box O1(FoxO1), peroxisome proliferator-activated receptor-γ (PPARγ),insulin-like growth factor-1(IGF-1), glyceraldehydes-3-phosphate dehydrogenase(GAPDH), and leptin, during bovine preadipocyte differentiation were investigated using real-time quantitative PCR. The intracellular triglyceride concentration of BSPs increased more dramatically than that of BIPs during cell differentiation. The expression of SIRT1 and other genes occurred in the BSPs and BIPs during differentiation indicating that different mechanisms underlie the adipogenesis of BSPs and BIPs, and that the BSPs cultured in vitro show a higher differentiation capacity than BIPs.
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