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61.
62.
Jun-ichi Kadokawa Masa-aki Murakami Akihiko Takegawa Yoshiro Kaneko 《Carbohydrate polymers》2009,75(1):180-183
This paper reports the preparation of a cellulose–starch composite gel from an ionic liquid solution. The gel was obtained by keeping the homogeneous mixture of cellulose (10% w/w) and starch (5% w/w) in 1-butyl-3-methylimidazolium chloride (BMIMCl) for several days at room temperature and characterized by elemental analysis, X-ray diffraction, and thermal gravimetric analysis. Furthermore, the production of the fibrous material composed of cellulose and starch by reconstitution from the homogeneous mixture (10% w/w each) in BMIMCl is demonstrated. 相似文献
63.
64.
Brain activities related to cognitive functions, such as attention, occur with unknown and variable delays after stimulus onsets. Recently, we proposed a method (Common Waveform Estimation, CWE) that could extract such brain activities from magnetoencephalography (MEG) or electroencephalography (EEG) measurements. CWE estimates spatiotemporal MEG/EEG patterns occurring with unknown and variable delays, referred to here as unlocked waveforms, without hypotheses about their shapes. The purpose of this study is to demonstrate the usefulness of CWE for cognitive neuroscience. For this purpose, we show procedures to estimate unlocked waveforms using CWE and to examine their role. We applied CWE to the MEG epochs during Go trials of a visual Go/NoGo task. This revealed unlocked waveforms with interesting properties, specifically large alpha oscillations around the temporal areas. To examine the role of the unlocked waveform, we attempted to estimate the strength of the brain activity of the unlocked waveform in various conditions. We made a spatial filter to extract the component reflecting the brain activity of the unlocked waveform, applied this spatial filter to MEG data under different conditions (a passive viewing, a simple reaction time, and Go/NoGo tasks), and calculated the powers of the extracted components. Comparing the powers across these conditions suggests that the unlocked waveforms may reflect the inhibition of the task-irrelevant activities in the temporal regions while the subject attends to the visual stimulus. Our results demonstrate that CWE is a potential tool for revealing new findings of cognitive brain functions without any hypothesis in advance. 相似文献
65.
The destruction of blood–brain barrier (BBB) and blood-nerve barrier (BNB) has been considered to be a key step in the disease
process of a number of neurological disorders including cerebral ischemia, Alzheimer’s disease, multiple sclerosis, and diabetic
neuropathy. Although glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF) facilitate
neuronal or axonal regeneration in the brain or peripheral nerves, their action in the BBB and BNB remains unclear. The purpose
of the present study was to elucidate whether these neurotrophic factors secreted from the brain or peripheral nerve pericytes
increase the barrier function of the BBB or BNB, using our newly established human brain microvascular endothelial cell (BMEC)
line or peripheral nerve microvascular endothelial cell (PnMEC) line. GDNF increased the expression of claudin-5 and the transendothelial
electrical resistance (TEER) of BMECs and PnMECs, whereas BDNF did not have this effect. Furthermore, we herein demonstrate
that the GDNF secreted from the brain and peripheral nerve pericytes was one of the key molecules responsible for the up-regulation
of claudin-5 expression and the TEER value in the BBB and BNB. These results indicate that the regulation of GDNF secreted
from pericytes may therefore be a novel therapeutic strategy to modify the BBB or BNB functions and promote brain or peripheral
nerve regeneration. 相似文献
66.
Muramatsu M Ohto C Obata S Sakuradani E Shimizu S 《Applied microbiology and biotechnology》2008,80(4):589-595
Squalene synthase inhibitors significantly accelerate the production of farnesol by various microorganisms. However, farnesol
production by Saccharomyces cerevisiae ATCC 64031, in which the squalene synthase gene is deleted, was not affected by the inhibitors, indicating that farnesol
accumulation is enhanced in the absence of squalene synthase activity. The combination of diphenylamine as an inhibitor of
carotenoid biosynthesis and a squalene synthase inhibitor increases geranylgeraniol production by a yeast, Rhodotorula rubra NBRC 0870. An ent-kauren synthase inhibitor also enhances the production of farnesol and geranylgeraniol by a filamentous
fungus, Gibberella fujikuroi NBRC 30336. These results indicate that the inhibition of downstream enzymes from prenyl diphosphate synthase leads to the
production of farnesol and geranylgeraniol. 相似文献
67.
Sugar regulates a variety of genes and controls plant growth and development similarly to phytohormones. As part of a screen for Arabidopsis mutants with defects in sugar-responsive gene expression, we identified a loss-of-function mutation in the HOOKLESS1 (HLS1) gene. HLS1 was originally identified to regulate apical hook formation of dark-grown seedlings (Lehman et al., 1996, Cell 85: 183-194). In hls1, sugar-induced gene expression in excised leaf petioles was more sensitive to exogenous sucrose than that in the wild type. Exogenous IAA partially repressed sugar-induced gene expression and concomitantly activated some auxin response genes such as AUR3 encoding GH3-like protein. The repression and the induction of gene expression by auxin were attenuated and enhanced, respectively, by the hls1 mutation. These results suggest that HLS1 plays a negative role in sugar and auxin signaling. Because AUR3 GH3-like protein conjugates free IAA to amino acids (Staswick et al., 2002, Plant Cell 14: 1405-1415; Staswick et al., 2005, Plant Cell 17: 616-627), enhanced expression of GH3-like genes would result in a decrease in the free IAA level. Indeed, hls1 leaves accumulated a reduced level of free IAA, suggesting that HLS1 may be involved in negative feedback regulation of IAA homeostasis through the control of GH3-like genes. We discuss the possible mechanisms by which HLS1 is involved in auxin signaling for sugar- and auxin-responsive gene expression and in IAA homeostasis. 相似文献
68.
Removal and recovery of phosphorus from water by means of adsorption onto orange waste gel loaded with zirconium 总被引:4,自引:0,他引:4
Biswas BK Inoue K Ghimire KN Harada H Ohto K Kawakita H 《Bioresource technology》2008,99(18):8685-8690
Orange waste, an available biomass, was immobilized with zirconium(IV) to investigate its feasibility for phosphate removal from an aquatic environment. Kinetics, effects of pH and foreign anions, and the adsorption isotherm for phosphate have been examined. The adsorption capacity has been compared to that of two commercially available adsorbents such as zirconium ferrite and MUROMAC XMC 3614. The prepared gel was an effective adsorption gel for phosphate removal with a reasonably high sorption capacity of 57mg-P/g, which was four times higher than that of zirconium ferrite. The highest removal of phosphate was observed at low pH, whereas higher pH suppressed phosphate removal, but even up to pH 9 more than 85% phosphate removal was observed. Adsorbed phosphate was eluted by NaOH solution. Fixed bed column-mode experiments confirmed the complete adsorption of phosphate in continuous-mode operation. Throughout the operating conditions, zirconium was not leaked. 相似文献
69.
Oozono S Yamauchi N Nishimura K Matsumoto K Watanabe R Kubota K Aramaki S Sato F Wood C Soh T Kizaki K Hattori MA 《Journal of experimental zoology. Part B. Molecular and developmental evolution》2008,310(8):642-649
Implantation serine protease (ISP) was first identified in the uteri of pregnant mice. It is thought that ISP may have an important role in the initiation of implantation. However, the expression status and detailed functions of ISP remain unclear. In this study, the expression of ISP was investigated in the rat uterus. The analysis of two rat genes registered in GenBank, accession nos. XM_220240 and XM_577076, exhibited high identities to the mouse ISP2 genes, respectively at an mRNA level. We labeled the former as rISP2a and the latter as rISP2b. Using RT-PCR, we found that both genes were expressed in the uterus. Specifically, rISP2a mRNA was detected in the uterus throughout pregnancy, whereas rISP2b mRNA was only expressed in the uterus from day 5 of pregnancy until the end of gestation. Expression of both genes was observed specifically within the endometrial gland epithelium. Furthermore, rISP2a was also observed to be expressed in the fetus and placenta, whereas rISP2b expression was observed in the fetus but not in the placenta. An expressional signal of the rISP2a gene was observed in the spongiotrophoblasts, giant cells and decidual endometrium in the placenta. In the embryo, the ventral specific region was positive in rISP2a and rISP2b gene expression. These findings indicate the possibility that the presently examined genes with high identity to mouse ISP2 may play some role not only during the implantation phase, but also in the development of the placenta and embryo. 相似文献
70.
A thermophilic cyanobacterium Synechococcus elongatus has three different Class I prenyltransferase genes 总被引:1,自引:0,他引:1
Ohto Chikara Ishida Chika Nakane Hiroyuki Muramatsu Masayoshi Nishino Tokuzo Obata Shusei 《Plant molecular biology》1999,40(2):307-321
Prenyltransferases (prenyl diphosphate synthases), which are a broad group of enzymes that catalyze the consecutive condensation of homoallylic diphosphate of isopentenyl diphosphates (IPP, C5) with allylic diphosphates to synthesize prenyl diphosphates of various chain lengths, have highly conserved regions in their amino acid sequences. Based on the above information, three prenyltransferase homologue genes were cloned from a thermophilic cyanobacterium, Synechococcus elongatus. Through analyses of the reaction products of the enzymes encoded by these genes, it was revealed that one encodes a thermolabile geranylgeranyl (C20) diphosphate synthase, another encodes a farnesyl (C15) diphosphate synthase whose optimal reaction temperature is 60 °C, and the third one encodes a prenyltransferase whose optimal reaction temperature is 75 °C. The last enzyme could catalyze the synthesis of five prenyl diphosphates of farnesyl, geranylgeranyl, geranylfarnesyl (C25), hexaprenyl (C30), and heptaprenyl (C35) diphosphates from dimethylallyl (C5) diphosphate, geranyl (C20) diphosphate, or farnesyl diphosphate as the allylic substrates. The product specificity of this novel kind of enzyme varied according to the ratio of the allylic and homoallylic substrates. The situations of these three S. elongatus enzymes in a phylogenetic tree of prenyltransferases are discussed in comparison with a mesophilic cyanobacterium of Synechocystis PCC6803, whose complete genome has been reported by Kaneko et al. (1996). 相似文献