469 research outputs found
Agricultural development and the opportunities for aquatic resources research in China
China is a large and rapidly developing country. Fisheries and aquaculture have been prominent sectors in the contribution to GDP and the provision of food security, export revenue, and livelihoods for the poor. The rapid development has come at some cost to the environment and the sustainability of natural resources. Levels of marine fisheries catches are stagnant. Some of the rivers and major lakes are polluted and the restoration of the productivity of these lakes is of key concern. These Proceedings, made up of four papers that leading Chinese experts presented to WorldFish Center in 2002, review four aspects of these trends: agricultural development, environmental issues and the contribution of aquaculture and fisheries to development in China.Agricultural development, Aquaculture development, Living resources, Research, WorldFish Center, WorldFish Center Contrib. No. 1668, China,
SPH simulation of free overfall in open channels with even and uneven bottom
The free overfall can be used as a simple and accurate device for flow measurement in open channels. In the past, the solution to this problem was found mainly through simplified theoretical expressions or on the basis of experimental data. In this paper, using the meshless smoothed particle hydrodynamics (SPH) method, the free overfall in open channels with even and uneven bottom is investigated. For the even bottom case, subcritical, critical and supercritical flows are simulated. For the uneven bottom case, supercritical flows with different Froude numbers are considered. The free surface profiles are predicted and compared with theoretical and experimental solutions in literature and good agreements are obtained. Keywords: SPH, free overfall, even and uneven bottom, subcritical flow, critical flow, supercritical flow
Rapid filling of pipelines with the SPH particle method
The paper reports the development and application of a SPH (smoothed particle hydrodynamics) based simulation of rapid filling of pipelines, for which the rigid-column model is commonly used. In this paper the water-hammer equations with a moving boundary are used to model the pipe filling process, and a mesh-less Lagrangian particle approach is employed to solve the governing equations. To assign boundary conditions with time-dependent (upstream) and constant (downstream) pressure, the SPH pressure boundary concept proposed recently in literature is used and extended. Except for imposing boundary conditions, this concept also ensures completeness of the kernels associated with particles close to the boundaries. As a consequence, the boundary deficiency problem encountered in conventional SPH is remedied. The employed particle method with the SPH pressure boundary concept aims to predict the transients occurring during rapid pipe filling. It is validated against laboratory tests, rigid-column solutions and numerical results from literature. Results obtained with the present approach show better agreement with the test data than those from rigid-column theory and the elastic model solved by the box scheme. It is concluded that SPH is a promising tool for the simulation of rapid filling of pipelines with undulating elevation profiles. Keywords: Rapid filling of pipelines; Undulating elevation profile; SP
Preparation, characterization and anti-ageing activity of Gastrodia elata blume polysaccharide
Gastrodia elata Blume polysaccharide (GEP) was extracted and then chemically characterised. Its antioxidant activity was evaluated in vitro and in vivo. The results of the in vitro investigation show that GEP consists of glucose with molecular weight of 875 185 Da and exhibits high hydroxyl radical scavenging, as well as 2,2-diphenyl-1- picrylhydrazyl activity and reducing capacity. For antioxidant activity in vivo, D-galactose-induced-aged mice were orally administered with three different doses of GEP over a period of 6 weeks. The administration of GEP dosedependently increased the body weight gain rates, liver and brain indices, superoxide dismutase and glutathione peroxidase activities, and malondialdehyde levels in the sera and brains of ageing mice. These results suggest that GEP exhibits high antioxidant activity and can retard human ageing associated with free radicals
Combination of cyclooxygenase-2 inhibitor and doxorubicin increases the growth inhibition and apoptosis in human hepatocellular carcinoma cells
Inhibition of cyclooxygenase (COX)-2 elicits therapeutic effects in solid tumors that are coupled with the inhibition of cell proliferation and induction of apoptosis in tumor cells. Aim: This study was designed to investigate the role of COX-2 inhibitor nimesulide in cell growth and apoptosis of the cultured human hepatocellular carcinoma HepG2 cells. Methods: We performed the MTT assay, flow cytometric analysis and cell morphology study to evaluate growth inhibition and cell apoptosis upon the action of nimesulide alone or along with doxorubicin, a common agent for the treatment of human hepatocellular carcinoma. Results: Our results showed that the treatment of HepG2 cells with more than 50 Β΅M of nimesulide suppressed COX-2 enzyme activity because of reduced PGE2 production, and then induced growth inhibition and cell apoptosis despite no alterations of COX-2 protein expression. Importantly, the combination of 50 Β΅M or 100 Β΅M of nimesulide and low concentrations (5 Β΅M to 20 Β΅M) of doxorubicin resulted in enhanced cell growth inhibition, apoptosis induction and reduced VEGF production. Conclusion: These data suggest synergistic and/or additive effects of COX-2 inhibitors and chemotherapeutic agents, and may provide the rational for clinical studies of COX-2 inhibitors on the treatment or chemoprevention of human hepatocellular carcinoma.Π£Π³Π½Π΅ΡΠ΅Π½ΠΈΠ΅ ΡΠΈΠΊΠ»ΠΎΠΎΠΊΡΠΈΠ³Π΅Π½Π°Π·Ρ-2 (Π¦ΠΠ-2) ΠΎΠΊΠ°Π·ΡΠ²Π°Π΅Ρ ΡΠ΅ΡΠ°ΠΏΠ΅Π²ΡΠΈΡΠ΅ΡΠΊΠΈΠΉ ΡΡΡΠ΅ΠΊΡ ΠΏΡΠΈ Π»Π΅ΡΠ΅Π½ΠΈΠΈ Π±ΠΎΠ»ΡΠ½ΡΡ
Ρ ΡΠΎΠ»ΠΈΠ΄Π½ΡΠΌΠΈ ΠΎΠΏΡΡ
ΠΎΠ»ΡΠΌΠΈ
ΠΈ ΡΠΎΠΏΡΠΎΠ²ΠΎΠΆΠ΄Π°Π΅ΡΡΡ ΡΠ½ΠΈΠΆΠ΅Π½ΠΈΠ΅ΠΌ ΠΏΡΠΎΠ»ΠΈΡΠ΅ΡΠ°ΡΠΈΠΈ ΠΎΠΏΡΡ
ΠΎΠ»Π΅Π²ΡΡ
ΠΊΠ»Π΅ΡΠΎΠΊ ΠΈ ΠΈΠ½Π΄ΡΠΊΡΠΈΠ΅ΠΉ Π°ΠΏΠΎΠΏΡΠΎΠ·Π°. Π¦Π΅Π»Ρ: ΠΈΠ·ΡΡΠ΅Π½ΠΈΠ΅ ΡΠΎΠ»ΠΈ ΠΈΠ½Π³ΠΈΠ±ΠΈΡΠΎΡΠ°
Π¦ΠΠ-2 β Π½ΠΈΠΌΠ΅ΡΡΠ»ΠΈΠ΄Π° Π² ΠΏΡΠΎΡΠ΅ΡΡΠ°Ρ
ΡΠΎΡΡΠ° ΠΈ Π°ΠΏΠΎΠΏΡΠΎΠ·Π° ΠΊΡΠ»ΡΡΠΈΠ²ΠΈΡΠΎΠ²Π°Π½Π½ΡΡ
ΠΊΠ»Π΅ΡΠΎΠΊ Π³Π΅ΠΏΠ°ΡΠΎΠΊΠ°ΡΡΠΈΠ½ΠΎΠΌΡ ΡΠ΅Π»ΠΎΠ²Π΅ΠΊΠ° HepG2.
ΠΠ΅ΡΠΎΠ΄Ρ: Π΄Π»Ρ ΠΎΡΠ΅Π½ΠΊΠΈ Π°ΠΏΠΎΠΏΡΠΎΠ·Π° ΠΈ ΡΠ³Π½Π΅ΡΠ΅Π½ΠΈΡ ΡΠΎΡΡΠ° ΠΊΠ»Π΅ΡΠΎΠΊ ΠΏΡΠΈ ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΠΈ Π½ΠΈΠΌΠ΅ΡΡΠ»ΠΈΠ΄Π° ΡΠ°ΠΌΠΎΡΡΠΎΡΡΠ΅Π»ΡΠ½ΠΎ ΠΈ Π² ΡΠΎΡΠ΅ΡΠ°Π½ΠΈΠΈ Ρ
Π΄ΠΎΠΊΡΠΎΡΡΠ±ΠΈΡΠΈΠ½ΠΎΠΌ ΠΏΡΠΈΠΌΠ΅Π½ΡΠ»ΠΈ MTT-Π°Π½Π°Π»ΠΈΠ·, ΠΏΡΠΎΡΠΎΡΠ½ΡΡ ΡΠΈΡΠΎΠΌΠ΅ΡΡΠΈΡ ΠΈ ΡΡΠ°Π½Π΄Π°ΡΡΠ½ΡΠ΅ ΠΌΠΎΡΡΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΠΌΠ΅ΡΠΎΠ΄Ρ. Π Π΅Π·ΡΠ»ΡΡΠ°ΡΡ:
ΡΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΎ, ΡΡΠΎ ΠΎΠ±ΡΠ°Π±ΠΎΡΠΊΠ° ΠΊΠ»Π΅ΡΠΎΠΊ HepG2 cells Π½ΠΈΠΌΠ΅ΡΡΠ»ΠΈΠ΄ΠΎΠΌ Π² ΠΊΠΎΠ½ΡΠ΅Π½ΡΡΠ°ΡΠΈΠΈ > 50 ΞΌM ΠΏΡΠΈΠ²ΠΎΠ΄ΠΈΠ»Π° ΠΊ ΡΠ³Π½Π΅ΡΠ΅Π½ΠΈΡ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ
Π¦ΠΠ-2 Π·Π° ΡΡΠ΅Ρ ΡΠ½ΠΈΠΆΠ΅Π½ΠΈΡ ΠΏΡΠΎΠ΄ΡΠΊΡΠΈΠΈ PGE2
, ΠΏΠΎΡΠ»Π΅ ΡΠ΅Π³ΠΎ ΠΎΡΠΌΠ΅ΡΠ°Π»ΠΈ ΠΏΠΎΠ΄Π°Π²Π»Π΅Π½ΠΈΠ΅ ΡΠΎΡΡΠ° ΠΈ Π°ΠΏΠΎΠΏΡΠΎΠ· ΠΊΠ»Π΅ΡΠΎΠΊ ΠΏΡΠΈ Π½Π΅ΠΈΠ·ΠΌΠ΅Π½Π΅Π½Π½ΠΎΠΌ
ΡΡΠΎΠ²Π½Π΅ ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΠΈ Π¦ΠΠ-2. ΠΠΎΠΌΠ±ΠΈΠ½ΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠ΅ ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΠ΅ 50 ΞΌM ΠΈΠ»ΠΈ 100 ΞΌM Π½ΠΈΠΌΠ΅ΡΡΠ»ΠΈΠ΄Π° ΠΈ Π΄ΠΎΠΊΡΠΎΡΡΠ±ΠΈΡΠΈΠ½Π° Π² ΠΊΠΎΠ½ΡΠ΅Π½ΡΡΠ°ΡΠΈΠΈ
5β20 ΞΌM ΠΎΠ±ΡΡΠ»ΠΎΠ²ΠΈΠ»ΠΎ ΡΡΠΈΠ»Π΅Π½Π½ΠΎΠ΅ ΡΠ³Π½Π΅ΡΠ΅Π½ΠΈΠ΅ ΡΠΎΡΡΠ° ΠΊΠ»Π΅ΡΠΎΠΊ, ΠΈΠ½Π΄ΡΠΊΡΠΈΠΈ Π°ΠΏΠΎΠΏΡΠΎΠ·Π° ΠΈ ΡΠ½ΠΈΠΆΠ΅Π½ΠΈΠ΅ ΠΏΡΠΎΠ΄ΡΠΊΡΠΈΠΈ VEGF. ΠΡΠ²ΠΎΠ΄Ρ:
ΠΏΠΎΠ»ΡΡΠ΅Π½Π½ΡΠ΅ Π΄Π°Π½Π½ΡΠ΅ ΡΠ²ΠΈΠ΄Π΅ΡΠ΅Π»ΡΡΡΠ²ΡΡΡ ΠΎ ΡΠΈΠ½Π΅ΡΠ³ΠΈΡΠ΅ΡΠΊΠΎΠΌ ΠΈ/ΠΈΠ»ΠΈ Π°Π΄Π΄ΠΈΡΠΈΠ²Π½ΠΎΠΌ ΡΡΡΠ΅ΠΊΡΠ΅ ΠΏΡΠΈ ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΠΈ ΠΈΠ½Π³ΠΈΠ±ΠΈΡΠΎΡΠΎΠ² Π¦ΠΠ-2
ΠΈ Ρ
ΠΈΠΌΠΈΠΎΡΠ΅ΡΠ°ΠΏΠ΅Π²ΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΏΡΠ΅ΠΏΠ°ΡΠ°ΡΠΎΠ²
Polarization of AGN in UV Spectral Range
We present the review of some new problems in cosmology and physics of stars
in connection with future launching of WSO. We discuss three problems. UV
observations of distant z > 6 quasars allow to obtain information on the soft <
1 KeV X-ray radiation of the accretion disk around a supermassive black hole
because of its cosmological redshift. Really the region of X-ray radiation is
insufficiently investigated because of high galactic absorption. In a result
one will get important information on the reionization zone of the Universe.
Astronomers from ESO revealed the effect of alignment of electric vectors of
polarized QSOs. One of the probable mechanism of such alignment is the
conversion of QSO radiation into low mass pseudoscalar particles (axions) in
the extragalactic magnetic field. These boson like particles have been
predicted by new SUSY particle physics theory. Since the probability of such
conversion is increasing namely in UV spectral range one can expect the strong
correlation between UV spectral energy distribution of QSO radiation and
polarimetric data in the optical range. In the stellar physics one of the
interesting problems is the origin of the X-ray sources with super Eddington
luminosities. The results of UV observations of these X-ray sources will allow
to find the origin of these sources as accreting intermediate mass black holes.Comment: 6 pages, 3 figure
A strong steric hindrance effect on ground state, excited state, and charge separated state properties of a CuI-diimine complex captured by X-ray transient absorption spectroscopy
Steady-state and transient structures of a copper diimine dye sensitizer on TiO2 nanoparticles undergoing photoinduced interfacial electron transfer are determined.</p
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