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141.
废橡胶颗粒浸提液物质释放及其浸种对草坪植物生长的影响 总被引:3,自引:0,他引:3
纯胶粒浸提液、胶粒与壤土混合的浸提液中重金属含量分析表明,纯胶粒浸提液中Zn含量最高,其次为Pb,而Cd与Cu最少;与纯胶粒浸提液相比,胶粒与壤土混合的浸提液中Zn含量显著降低.紫外吸收光谱图显示,胶粒粒径越小,浸提液中有机物越复杂.用4种不同粒径胶粒的浸提液对2种草坪植物种子浸种处理后进行培养,研究了草坪植物的生长效应.结果表明,胶粒浸提液浸种对2种草坪植物的种子萌发率影响不大,但对株高产生不同的影响.对黑麦草而言,以2~4 mm胶粒浸提液浸种的株高为最高,1~2和4~6 mm胶粒浸提液浸种株高与之差异较大,分别降低1.52和1.32 cm,但均与对照无显著差异.对于高羊茅,以粒径1~2 mm胶粒浸提液浸种的株高为最低,比对照降低了18.76%,其它处理间无明显差异.浸提液浸种对黑麦草地下生物量有明显的抑制作用,但对根长生长有促进作用.胶粒浸提液浸种对2种草坪植物的地上生物量无明显影响.从胶粒浸提液的物质释放及其浸种对草坪植物生长的影响来看,废胶粒可用于运动场草坪的基质组配. 相似文献
142.
Neuroprotection and free radical scavenging effects of <Emphasis Type="Italic">Osmanthus fragrans</Emphasis> 总被引:1,自引:0,他引:1
The ethanol extract of dried flowers Osmanthus fragrans (OFE) was assessed for free radical scavenging effects measured by the bleaching of the 1,1-diphenyl-2-picryl-hydrazyl (DPPH)
radical, scavenging of the hydroxyl anion, investigation of the ferric reducing/antioxidant power (FRAP) and lipid-peroxidation
inhibition in rat tissues. OFE contained a high amount of total flavonoid and polyphenol. OFE presented the effects in the
metal reducing power, FRAP assay with IC50 values of 0.23 μg/ml, and 7.74 μg/ml, respectively. OFE presented similar activities toward the DPPH and hydroxyl anion scavenging
ability with IC50 values of 10 μg/ml. OFE with IC50 values between 46 and 97 μg/ml inhibited lipid peroxidation initiated by ferrous chloride in rat brain, liver, heart and kidney
mitochodrias. Moreover, the neuroprotective activity of OFE was investigated under different insults (glutamate, arachidonic
acid, and 6-hydroxydopamine) in Wistar rat primary cortical neurons. OFE with EC50 values between 66 and 165 μg/ml attenuated the neurotoxicity on MTT and LDH assays. In addition, the AKT protein expression
of excitotoxicity and oxidative stress was displayed by western blotting analysis. OFE could up-regulate the glutamate and
6-OHDA decreased AKT expression. This is the first demonstration of the neuroprotective, free radical scavenging and anti-oxidative
effects of O. fragrans. 相似文献
143.
Catania MV D'Antoni S Bonaccorso CM Aronica E Bear MF Nicoletti F 《Molecular neurobiology》2007,35(3):298-307
Group I metabotropic glutamate receptors (mGlu1 and mGlu5) are coupled to polyphosphoinositide hydrolysis and are involved
in activity-dependent forms of synaptic plasticity, both during development and in the adult life. Group I mGlu receptors
can also regulate proliferation, differentiation, and survival of neural stem/progenitor cells, which further support their
role in brain development. An exaggerated response to activation of mGlu5 receptors may underlie synaptic dysfunction in Fragile
X syndrome, the most common inherited form of mental retardation. In addition, group I mGlu receptors are overexpressed in
dysplastic neurons of focal cortical dysplasia and hemimegaloencephaly, which are disorders of cortical development associated
with chronic epilepsy. Drugs that block the activity of group I mGlu receptors (in particular, mGlu5 receptors) are potentially
helpful for the treatment of Fragile X syndrome and perhaps other neurodevelopmental disorders. 相似文献
144.
We consider a mathematical model of mesoscopic human cortical ictal electrical activity. We compare the model results with
ictal electrocortical data recorded from three human subjects and show how the two agree. We determine that, in the model
system, seizures result from increased connectivity between excitatory and inhibitory cell populations, or from decreased
connectivity within either excitatory or inhibitory cell populations. We compare the model results with the disinhibition
and 4-AP models of epilepsy and suggest how the model may guide the development of new anticonvulsant therapies. 相似文献
145.
Coelomocytes, the immunodefense cells of the earthworm Lumbricus terrestris, are exposed to changing osmotic pressures as the worm's coelomic fluid responds to fluctuating wet-dry conditions of the surrounding soil. Using light and fluorescence microscopy combined with actin and tubulin disrupting drugs, we determined the effects of changing osmotic pressure on coelomocyte morphology. The coelomocytes from L. terrestris respond to an increase in environmental osmotic pressure from isotonic conditions (170 mOsm) to hypertonic conditions (715 mOsm) by changing from a round/petalloid morphology to a filopodial morphology. Cytoskeletal fluorescent staining studies indicate that for filopodia to form, the actin cortical ring, present in most coelomocytes in isotonic conditions, must be disrupted. Breakdown of the actin ring by exposure to a hypertonic environment or actin disrupting drugs allows the formation of actin or tubulin-based filopodia. The filopodia, or podial-like extensions formed by earthworm coelomocytes, may enable the cells to better explore their environment. 相似文献
146.
The purpose of this research was to develop and optimize a controlled-release multiunit floating system of a highly water
soluble drug, ranitidine HCl, using Compritol, Gelucire 50/13, and Gelucire 43/01 as lipid carriers. Ranitidine HCl-lipid
granules were prepared by the melt granulation technique and evaluated for in vitro floating and drug release. ethyl cellulose,
methylcellulose, and hydroxypropyl methylcellulose were evaluated as release rate modifiers. A 32 full factorial design was used for optimization by taking the amounts of Gelucire 43/01 (X
1) and ethyl cellulose (X
2) as independent variables, and the percentage drug released in 1(Q1), 5(Q5), and 10 (Q10) hours as dependent variables. The results revealed that the moderate amount of Gelucire 43/01 and ethyl cellulose provides
desired release of ranitidine hydrochloride from a floating system. Batch F4 was considered optimum since it contained less
Gelucire and was more similar to the theoretically predicted dissolution profile (f2=62.43). The temperature sensitivity studies for the prepared formulations at 40°C/75% relative humidity for 3 months showed
no significant change in in vitro drug release pattern. These studies indicate that the hydrophobic lipid Gelucire 43/01 can
be considered an effective carrier for design of a multiunit floating drug delivery system for highly water soluble drugs
such as ranitidine HCl.
Published: April 13, 2007 相似文献
147.
148.
Hiroshi Gomi Satomi Morikawa Naoki Shinmura Hiroaki Moki Tadashi Yasui Azuma Tsukise Seiji Torii Tsuyoshi Watanabe Yoshinori Maeda Masahiro Hosaka 《The journal of histochemistry and cytochemistry》2015,63(5):350-366
The expression of secretogranin III (SgIII) in chicken endocrine cells has not been investigated. There is limited data available for the immunohistochemical localization of SgIII in the brain, pituitary, and pancreatic islets of humans and rodents. In the present study, we used immunoblotting to reveal the similarities between the expression patterns of SgIII in the common endocrine glands of chickens and rats. The protein–protein interactions between SgIII and chromogranin A (CgA) mediate the sorting of CgA/prohormone core aggregates to the secretory granule membrane. We examined these interactions using co-immunoprecipitation in chicken endocrine tissues. Using immunohistochemistry, we also examined the expression of SgIII in a wide range of chicken endocrine glands and gastrointestinal endocrine cells (GECs). SgIII was expressed in the pituitary, pineal, adrenal (medullary parts), parathyroid, and ultimobranchial glands, but not in the thyroid gland. It was also expressed in GECs of the stomach (proventriculus and gizzard), small and large intestines, and pancreatic islet cells. These SgIII-expressing cells co-expressed serotonin, somatostatin, gastric inhibitory polypeptide, glucagon-like peptide-1, glucagon, or insulin. These results suggest that SgIII is expressed in the endocrine cells that secrete peptide hormones, which mature via the intragranular enzymatic processing of prohormones and physiologically active amines in chickens. 相似文献
149.
150.
Michael R Bron AJ 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2011,366(1568):1278-1292
Cataract is a visible opacity in the lens substance, which, when located on the visual axis, leads to visual loss. Age-related cataract is a cause of blindness on a global scale involving genetic and environmental influences. With ageing, lens proteins undergo non-enzymatic, post-translational modification and the accumulation of fluorescent chromophores, increasing susceptibility to oxidation and cross-linking and increased light-scatter. Because the human lens grows throughout life, the lens core is exposed for a longer period to such influences and the risk of oxidative damage increases in the fourth decade when a barrier to the transport of glutathione forms around the lens nucleus. Consequently, as the lens ages, its transparency falls and the nucleus becomes more rigid, resisting the change in shape necessary for accommodation. This is the basis of presbyopia. In some individuals, the steady accumulation of chromophores and complex, insoluble crystallin aggregates in the lens nucleus leads to the formation of a brown nuclear cataract. The process is homogeneous and the affected lens fibres retain their gross morphology. Cortical opacities are due to changes in membrane permeability and enzyme function and shear-stress damage to lens fibres with continued accommodative effort. Unlike nuclear cataract, progression is intermittent, stepwise and non-uniform. 相似文献