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961.
Fatty acid composition of three species of Chlorella were studied under conditions of photoautotrophic and heterotrophic cultivation, nitrogen starvation, and outdoor in a photobioreactor. The composition 14:0, 16:0, 16:1, 16:2, 16:3, 18:0, 18:1, 18:2, α-18:3 is confirmed for Chlorella. Fatty acids with 20 carbon atoms and four or five double bonds are considered not originating from Chlorella. Other exceptions of this composition are interpreted as mixed algal culture, bacterial contamination or impurities. 相似文献
962.
Kim SJ Lee BH Lee YS Kang KS 《Biochemical and biophysical research communications》2007,360(3):593-599
Niemann-Pick type C disease (NPC) is a neurodegenerative and lipid storage disorder for which no effective treatment is known. We previously reported that neural stem cells derived from NPC1 mice showed impaired self-renewal and differentiation. We examined whether valproic acid (VPA), a histone deacetylase inhibitor, could enhance neuronal differentiation and recover defective cholesterol metabolism in neural stem cells (NSCs) from NPC1-deficient mice (NPC1(-/-)). VPA could induce neuronal differentiation and restore impaired astrocytes in NSCs from NPC1(-/-) mice. Importantly, an increasing level of cholesterol within NSCs from NPC1(-/-) mice could be reduced by VPA. Moreover, essential neurotrophic genes (TrkB, BDNF, MnSoD, and NeuroD) were up-regulated through the repression of the REST/NRSF and HDAC complex by the VPA treatment. Up-regulated neurotrophic genes were able to enhance neural differentiation and cholesterol homeostasis in neural stem cells from NPC1(-/-) mice. In this study, we suggested that, along with cholesterol homeostasis, impaired neuronal differentiation and abnormal morphology of astrocytes could be rescued by the inhibition of HDAC and REST/NRSF activity induced by VPA treatment. 相似文献
963.
External phosphorus load to a wetland with two shallow lakes in the Botshol Nature Reserve, The Netherlands, was reduced,
resulting in a rapid reduction of phytoplankton biomass and turbidity, and after 4 years, explosive growth of Characeae. The
clear water state was unstable, however, and the ecosystem then alternated between clear, high-vegetation and turbid, low-vegetation
states. A model of water quality processes was used in conjunction with a 14-year nutrient budget for Botshol to determine
if fluctuations in precipitation and nutrient load caused the ecosystem instability. The results indicate that, during wet
winters when groundwater level rose above surface water level, phosphorus from runoff was stored in the lake bottom and banks.
Stored phosphorus was released the following spring and summer under anaerobic sediment conditions, resulting in increased
phytoplankton density and light attenuation in the water column. During years with high net precipitation, flow from land
to surface water also transported humic acids, further increasing light attenuation. In years with dry winters, the phosphorus
and humic acid loads to surface water were reduced, and growth of submerged macrophytes was enhanced by clear water. Thus,
the temporal pattern of precipitation and flow from land to water gave a coherent, quantitative explanation of the observed
dynamics in phosphorus, phytoplankton, turbidity, and Characeae. Global warming has caused winters in The Netherlands to become
warmer and wetter during the last 50 years, increasing flow from land to water of humic acids and phosphorus and, ultimately,
enhancing instability of Characeae populations. In the first half of the 20th century interannual variation in precipitation
was not sufficient to cause large changes in internal P flux in Botshol, and submerged macrophyte populations were stable. 相似文献
964.
Silvia Gosiewska Anthony L. Spek Robertus J.M. Klein Gebbink 《Inorganica chimica acta》2007,360(1):405-417
Mononuclear iron(II) complexes of enantiopure Py(ProOH)2 (2) and Py(ProPh2OH)2 (3) ligands have been prepared with FeCl2 and Fe(OTf)2 · 2MeCN. Both ligands coordinate to the metal in a pentadentate fashion. Next to the meridional N,N′,N-coordination of the ligand, additional coordination of the oxygen atoms of both hydroxyl groups to the metal is found in complexes 4-7. Complex [FeCl(2)](Cl) (4) shows an octahedral geometry as determined by X-ray diffraction and is formed as a single diastereoisomer. The solution structures of complexes 4-7 were characterized by means of UV-Vis, IR, ESI-MS, conductivity and CD measurements. The catalytic potential of these complexes in the oxidation of alkenes and sulfides in the presence of H2O2 is presented. 相似文献
965.
966.
Gelmi ML Caputo F Clerici F Pellegrino S Giannaccini G Betti L Fabbrini L Schmid L Palego L Lucacchini A 《Bioorganic & medicinal chemistry》2007,15(24):7581-7589
Enantiopure constrained 1-aminocyclopentane-1,2,4-tricarboxylic acids containing the glutamic acid skeleton were prepared as two diastereomers characterized by having the carboxylic groups in position two and four cis-oriented to each other and trans with respect to 1-carboxylic group and all cis-oriented carboxylic groups, respectively. A biochemical screening of activity of the above amino acids was investigated on glutamate and 5-HT receptors to find a possible metabotropic agonist, acting on the serotoninergic system. 相似文献
967.
Dietary n-3 fatty acids generally attenuate elevated cyclooxygenase-2 (COX-2) levels in disease states. However, models of renal cystic disease (RCD) exhibit reduced renal COX-2 expression. Therefore, the in vivo regulation of COX-2 expression by dietary n-3 fatty acids was examined. In archived tissues from dietary studies, COX-2 protein and gene expression was up-regulated in diseased pcy mouse and Han:SPRD-cy rat kidneys when given diets containing eicosapentaenoic acid (EPA) and/or docosahexaenoic acid (DHA), but not those containing -linolenic acid (ALA), compared to control diets with linoleic acid (LA). The presence of disease was necessary to elicit these effects as COX-2 expression was unaltered by diet in normal kidneys. The effects were specific for COX-2, since COX-1 levels were unaltered by these dietary manipulations in either model. Thus, in RCD, diets containing EPA and DHA but not ALA appear to specifically up-regulate renal COX-2 gene and protein levels in vivo. 相似文献
968.
Human-specific expression of Siglec-6 in the placenta 总被引:3,自引:0,他引:3
969.
Kudo T Fujii T Ikegami S Inokuchi K Takayama Y Ikehara Y Nishihara S Togayachi A Takahashi S Tachibana K Yuasa S Narimatsu H 《Glycobiology》2007,17(1):1-9
The 3-fucosyl-N-acetyllactosamine [Lewis x (Le(x)), CD15, SSEA-1] carbohydrate structure is expressed on several glycolipids, glycoproteins, and proteoglycans of the nervous system and has been implicated in cell-cell recognition, neurite outgrowth, and neuronal migration during development. To characterize the functional role of Le(x) carbohydrate structure in vivo, we have generated mutant mice that lack alpha1,3-fucosyltransferase IX (Fut9(-/-)). Fut9(-/-) mice were unable to synthesize the Le(x) structure carried on glycoproteins and glycolipids in embryonic and adult brain. However, no obvious pathological differences between wild-type and Fut9(-/-) mice were found in brain. In behavioral tests, Fut9(-/-) mice exhibited increased anxiety-like responses in dark-light preference and in elevated plus maze tests. Immunohistochemical analysis showed that the number of calbindin-positive neurons was decreased in the basolateral amygdala in Fut9(-/-) mice. These observations indicated that the carbohydrates synthesized by Fut9 play critical roles in functional regulations of interneurons in the amygdalar subdivisions and suggested a role for the Le(x) structure in some aspects of emotional behavior in mice. 相似文献
970.