76 research outputs found
Expression and localization of estrogen receptor-β in annulus cells of the human intervertebral disc and the mitogenic effect of 17-β-estradiol in vitro
BACKGROUND: Recent evidence suggests that estrogens exert effects in different tissues throughout the body, and that the estrogen receptor β (ERβ) may be important for the action of estrogen (17-β-estradiol) on the skeleton. The cellular localization of ERβ in the human intervertebral disc, however, has not yet been explored. METHODS: Human disc tissue and cultured human disc cells were used for immunocytochemical localization of ERβ. mRNA was isolated from cultured human disc cells, and RT-PCR amplification of ERβ was employed to document molecular expression of this receptor. Cultured human disc cells were tested to determine if 17-β-estradiol stimulated cell proliferation. RESULTS: In this report data are presented which provide evidence for ERβ gene expression in human intervertebral disc cells in vivo and in vitro. Culture of annulus cells in the presence of 10(-7) M 17-β-estradiol significantly increased cell proliferation. CONCLUSIONS: These data provide new insight into the biology of cells in the annulus of the intervertebral disc
Prostaglandin E1 Alleviates Cognitive Dysfunction in Chronic Cerebral Hypoperfusion Rats by Improving Hemodynamics
Compensatory vascular mechanisms can restore cerebral blood flow (CBF) but fail to protect against chronic cerebral hypoperfusion (CCH)-mediated neuronal damage and cognitive impairment. Prostaglandin E1 (PGE1) is known as a vasodilator to protect against ischemic injury in animal models, but its protective role in CCH remains unclear. To determine the effect of PGE1 on cerebral hemodynamics and cognitive functions in CCH, bilateral common carotid artery occlusion (BCCAO) was used to mimic CCH in rats, which were subsequently intravenously injected with PGE1 daily for 2 weeks. Magnetic resonance imaging, immunofluorescence staining and Morris water maze (MWM) were used to evaluate CBF, angiogenesis, and cognitive functions, respectively. We found that PGE1 treatment significantly restored CBF by enhancing vertebral artery dilation. In addition, PGE1 treatment increased the number of microvascular endothelial cells and neuronal cells in the hippocampus, and decreased the numbers of astrocyte and apoptotic cells. In the MWM test, we further showed that the escape latency of CCH rats was significantly reduced after PGE1 treatment. Our results suggest that PGE1 ameliorates cognitive dysfunction in CCH rats by enhancing CBF recovery, sustaining angiogenesis, and reducing astrocyte activation and neuronal loss
Electro-optically active ring devices for CMOS-compatible optoelectronics
Lithium niobate (LiNbO3) has advantages of large electro-optic coefficients property and wide intrinsic bandwidth compared to traditional silicon as electro-optic material. A nested ring Mach–Zehnder interferometer (NR-MZI) intensity modulator on silicon-on-insulator has been proposed and investigated in this final year project.
The modulator design and optimization consists of the following main stages. Firstly, the cross-section optimization has been implemented to realize high modulation efficiency and optimum power confinement in LiNbO3. With properly adjusting cross-section parameters, maximum confined optical power of 88.13% is achievable in the top LiNbO3 film. Also linear tapering technique has been developed on the modulator input/output cross-section design for device integration purpose and further optimization is carried out to realize an efficient and low-loss power transition within the waveguide.
Then from the modulator layout view, the nested ring structure has been optimized using transfer matrix method. The performance dependence on structure dimensions are analyzed in detail. Three optimized designs are provided for industrial manufacture practice. The proposed optimization approaches in the project are also suitable for other types of ring based modulator design.Bachelor of Engineerin
Light-Time-Biomass Response Model for Predicting the Growth of Choy Sum (Brassica rapa var. parachinensis) in Soil-Based LED-Constructed Indoor Plant Factory for Efficient Seedling Production
10.3389/fpls.2021.623682Frontiers in Plant Science1262368
Study on the effect of samplers on the disturbance of dredger-filled soil structure by numerical simulation layering method
Through the use of the particle flow software simulation, the influences on the microscopic dynamic properties of high viscosity soft soil caused by the inner diameter, cut angle and wall thickness of the samplers were studied with the example of the dredged mud. The motion behavior of the inflection point of particle characteristics was compared in seven soil samples by dividing the soil layers. The results show that a convective displacement field of the soil particles is formed at the bottom, and the particles above the convection are mainly subject to tensile expansion while the particles below the convection are mainly compressed and contracted, which result in the regular changes in porosity and bending deformation of the soil layers. There is a synergistic relationship between the intersection of the porosity curve and the initial porosity curve and the convective position of the particle displacement field. There is a characteristic inflection point in the interlayer particle displacement with the soil layers behave as a bending deformation. The particle disturbance between the inflection points is not obvious and the particle disturbance outside the inflection points is larger. The deformation feature can be fitted to a rotating paraboloid with the lower opening and the disturbance of the seven groups soil samples can be assessed initially by the a value of the surface equation. The line connecting the inflection points of the interlayer features can be refitted to a paraboloid of rotation. The ratio of the volume of the paraboloid to the volume of the soil sample can be used to evaluate the originality of the soil sample
Hydrogen Gas Improves Seed Germination in Cucumber by Regulating Sugar and Starch Metabolisms
Hydrogen gas (H2), an important gaseous regulator, is involved in various plant growth and development processes. However, there have been few studies on the role of H2 in seed germination. In this study, the role and underlying mechanisms of H2 in enhancing seed germination were investigated in cucumber (Cucumis sativus L.). The results revealed that the germination rate, germ length, germination index, and vitality index of cucumber exhibited a dose-dependent relationship with the increase in concentrations of hydrogen-rich water (HRW, a H2 donor; 0, 1, 10, 25, 50, 75, and 100%), attaining the maximum values with 75% HRW treatment. Treatment with 75% HRW resulted in higher contents of soluble sugar, soluble protein, and starch than the control. Additionally, the activity of α-amylase, β-amylase, and total amylase was significantly improved by 75% HRW treatment compared to the control, reaching the maximum values at 36 h. Moreover, the expression levels of starch-related genes AMY and BMY and sugar-related genes SS4 and SS3 were significantly upregulated by 75% HRW treatment during germination, particularly at 36 h. These results suggest that H2 might promote cucumber seed germination by increasing sugar and starch metabolisms
The Antioxidant Defense System during Lanzhou Lily Scales Storage Is Modulated by Hydrogen Sulfide
As an important gaseous regulator, hydrogen sulfide (H2S) is involved in various aspects of plant processes, including seed germination, stomatal movement, and postharvest senescence. The preservation capacity of Lanzhou lily (Lilium davidii var. unicolor Salisb) scales fumigated with or without exogenously applied sodium hydrosulfide (NaHS, a H2S donor) was investigated in the current study. Results indicate that NaHS fumigation was able to extend storage life and elicit endogenous H2S production of postharvest Lanzhou lily scales with an optimal concentration at 0.8 mM. Moreover, exogenously applied NaHS (0.8 mM) led to higher soluble sugar, soluble protein, and ascorbic acid levels and lower total phenolic and flavonoid contents compared with those of the control. The application of 0.8 mM NaHS also reduced the lipid peroxidation level and reactive oxygen species (ROS) accumulation in scales, as indicated by the lower malondialdehyde (MDA) content, relative conductivity, lipoxygenase (LOX) activity, O2− production rate, and hydrogen per-oxide (H2O2) content. Further, scales treated with 0.8 mM NaHS exhibited significantly higher activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbic acid peroxidase (APX). Collectively, our data provide new insight into how the postharvest senescence of Lanzhou lily scales might be alleviated by H2S by enhancing antioxidant defense systems
Frequency spectrum method-based stress analysis for oil pipelines in earthquake disaster areas.
When a long distance oil pipeline crosses an earthquake disaster area, inertial force and strong ground motion can cause the pipeline stress to exceed the failure limit, resulting in bending and deformation failure. To date, researchers have performed limited safety analyses of oil pipelines in earthquake disaster areas that include stress analysis. Therefore, using the spectrum method and theory of one-dimensional beam units, CAESAR II is used to perform a dynamic earthquake analysis for an oil pipeline in the XX earthquake disaster area. This software is used to determine if the displacement and stress of the pipeline meet the standards when subjected to a strong earthquake. After performing the numerical analysis, the primary seismic action axial, longitudinal and horizontal displacement directions and the critical section of the pipeline can be located. Feasible project enhancement suggestions based on the analysis results are proposed. The designer is able to utilize this stress analysis method to perform an ultimate design for an oil pipeline in earthquake disaster areas; therefore, improving the safe operation of the pipeline
Effects of Hydrogen Sulfide on Sugar, Organic Acid, Carotenoid, and Polyphenol Level in Tomato Fruit
Hydrogen sulfide (H2S) is known to have a positive effect on the postharvest storage of vegetables and fruits, but limited results are available on its influence in fruit flavor quality. Here, we presented the effect of H2S on the flavor quality of tomato fruit during postharvest. H2S decreased the content of fructose, glucose, carotene and lycopene but increased that of soluble protein, organic acid, malic acid and citric acid. These differences were directly associated with the expression of their metabolism-related genes. Moreover, H2S treatment raised the contents of total phenolics, total flavonoids and most phenolic compounds, and up-regulated the expression level of their metabolism-related genes (PAL5, 4CL, CHS1, CHS2, F3H and FLS). However, the effects of the H2S scavenger hypotaurine on the above flavor quality parameters were opposite to that of H2S, thus confirming the role of H2S in tomato flavor quality. Thus, these results provide insight into the significant roles of H2S in tomato fruit quality regulation and implicate the potential application of H2S in reducing the flavor loss of tomato fruit during postharvest
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