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761.
Stimulus-locked averages of electroencephalography (EEG) and magnetoencephalography (MEG) epochs reveal characteristic waveforms. EEG/MEG generation models to have reconstruct such waveforms have been recently proposed. These models assume that evoked, phase-modulated, and amplitude-modulated activities occur solely or simultaneously. We propose a two-stage stimulus-locked averaging method, called phase-interpolated averaging, to investigate the EEG/MEG generation process. First, virtual EEG/MEG epochs, which would be obtained as if instantaneous phases for each time sampling point were on a phase-grid, are interpolated from actually measured EEG/MEG epochs. Then, the virtual EEG/MEG epochs are discrete Fourier transformed. A simulation revealed that the zeroth Fourier term revealed the evoked activity, the first Fourier term revealed the amplitude-modulated activity, and the condition number of the interpolation reflected the phase-modulated activity. On the basis of these facts, a preliminary EEG analysis implied that the evoked activity is much smaller than what would be expected by using conventional averaging, the evoked and phase-modulated activities simultaneously occur, and the amplitude-modulated activity occasionally associates with the evoked and phase-modulated activities. To the best of our knowledge, this is the first time that these three activities have been shown to coexist by actually separating them.  相似文献   
762.
Proteomics is critically dependent on optimal sample preparation. Particularly, the interface between protein digestion and mass spectrometric analysis has a large influence on the overall quality and sensitivity of the analysis. We here describe a novel procedure in which a very small disk of beads embedded in a Teflon meshwork is placed as a microcolumn into pipet tips. Termed Stage, for STop And Go Extraction, the procedure has been implemented with commercially available material (C18 Empore Disks (3M, Minneapolis, MN)) as frit and separation material. The disk is introduced in a simple and fast process yielding a convenient and completely reliable procedure for the production of self-packed microcolumns in pipet tips. It is held in place free of obstacles solely by the narrowing tip, ensuring optimized loading and elution of analytes. Five disks are conveniently placed in 1 min, adding <0.1 cent in material costs to the price of each tip. The system allows fast loading with low backpressure (>300 micro/min for the packed column using manual force) while eliminating the possibility of blocking. The loading capacity of C18-StageTips (column bed: 0.4 mm diameter, 0.5 mm length) is 2-4 microg of protein digest, which can be increased by using larger diameter or stacked disks. Five femtomole of tryptic BSA digest could be recovered quantitatively. We have found that the Stage system is well-suited as a universal sample preparation system for proteomics.  相似文献   
763.
Photoinduced phase transitions are of special interest in condensed matter physics because they can be used to change complex macroscopic material properties on the ultrafast timescale. Cooperative interactions between microscopic degrees of freedom greatly enhance the number and nature of accessible states, making it possible to switch electronic, magnetic or structural properties in new ways. Photons with high energies, of the order of electron volts, in particular are able to access electronic states that may differ greatly from states produced with stimuli close to equilibrium. In this study we report the photoinduced change in the lattice structure of a charge and orbitally ordered Nd(0.5)Sr(0.5)MnO(3) thin film using picosecond time-resolved X-ray diffraction. The photoinduced state is structurally ordered, homogeneous, metastable and has crystallographic parameters different from any thermodynamically accessible state. A femtosecond time-resolved spectroscopic study shows the formation of an electronic gap in this state. In addition, the threshold-like behaviour and high efficiency in photo-generation yield of this gapped state highlight the important role of cooperative interactions in the formation process. These combined observations point towards a 'hidden insulating phase' distinct from that found in the hitherto known phase diagram.  相似文献   
764.
The characteristics of granular sludge from full-scale upflow anaerobic sludge blanket reactors used for the treatment of brewery wastewater were investigated. Fluorescence in situ hybridization (FISH) analyses of settled granules from a reactor that had been treating brewery wastewater stably at COD removal rates of over 90% for more than 6 months showed that a methanogen of the genus Methanosaeta was predominant near the granule surface and that Bacteria were not abundant. The center of the granules was composed of dead or resting cells, or both, which were used as a support for active archaeal and bacterial cells near the surface. Periodic analysis of granules from full-scale plants showed that granules containing methanogens deep within them tended to float. Granules with a Bacteria layer on the surface also tended to float. On the basis of these findings, well-settled granules are considered to have methanogens that develop near the granule surface so that the gases generated during methane fermentation are readily released.  相似文献   
765.
The catalysis of methane steam reforming (MSR) by pure Ni honeycombs with high cell density of 2300 cells per square inch (cpsi) was investigated to develop efficient and inexpensive catalysts for hydrogen production. The Ni honeycomb catalyst was assembled using 30-μm-thick Ni foils, and showed much higher activity than that of a Ni honeycomb catalyst with cell density of 700 cpsi at a steam-to-carbon ratio of 1.36 and a gas hourly space velocity of 6400 h?1 in a temperature range of 873–1173 K. Notably, the activity increased approximately proportional to the increasing geometric specific surface area of the honeycombs. The turnover rate of the Ni honeycomb catalyst was higher than that of supported Ni catalysts. The changes in chemical state of the Ni catalyst during hydrogen reduction and MSR reaction were analyzed by in situ X-ray absorption fine structure spectroscopy, which revealed that deactivation was mainly due to oxidation of the surface Ni atoms. These results demonstrated that the high-cell-density Ni honeycomb catalyst exhibits good performance for MSR reaction, and easy regeneration of the deactivated Ni honeycomb catalyst is possible only via hydrogen reduction.  相似文献   
766.
Bacterial cellulose (BC) was produced by Acetobacter xylinum BPR 2001 and its acetan nonproducing mutant EP1 in corn steep liquor-fructose medium in a 10-l jar fermentor supplemented with different agar concentrations ranging from 0% to 1.0% (w/v). The BC productivity of the two strains was increased by adding agar. The maximum BC production of BPR 2001 at an agar concentration of 0.4% was 12.8 g/l compared with 8 g/l without agar. The mutant EP1 produced 11.6 g/l of BC at an agar concentration of 0.6%, while only 5.5 g/l was produced in the control. Enhanced productivity is associated with an increase in viscosity of the culture, dispersion of BC pellets, and number of free cells due to agar addition, suggesting that acetan produced by BPR 2001 has a critical role in enhanced BC production.  相似文献   
767.
This study aimed to evaluate the effects of osmotic dehydration sheet (ODS) packaging on the quality parameters of beef biceps femoris muscle samples stored at 4 °C for 0, 1, 3 and 7 days. Quality indices such as Hunter color values (L, a and b, the percentage of metmyoglobin (Met-Mb%), K value (freshness index), and the contents of adenosine triphosphate (ATP)-related compounds (ARCs), thiobarbituric acid reactive substances (TBA-RS) and volatile basic nitrogen (VBN) were measured. ODS gave lower a and b values and lower Met-Mb% compared with control samples wrapped in polyvinylidene chloride film (PVDCF) (P < 0.01), but had no effect on L (P < 0.01). As a result, with higher levels of osmotic dehydration produced by the ODS, the percentage of weight loss and the total contents of ARCs and inosine monophosphate of the samples also increased (P < 0.05). The K values of ODS samples were also significantly lower than PVDCF-wrapped samples (P < 0.05). Low performance ODS wrapping reduced the TBA-RS values below those found with PVDCF and high performance ODS processing (P < 0.01). Moreover, the use of ODS had no effect on VBN values. Thus, although the bright red of beef samples changed to a dark purple color and the weights of samples decreased, the ODS approach has potential as a tool for decreasing the deterioration of other quality indices such as Met-Mb%, TBA-RS, ARCs, K values and the VBN content of cold-stored beef.  相似文献   
768.
Bovine lactoferrin was hydrolysed with a range of proteolytic enzymes including calf rennet, fungal rennin, and porcine pepsin. Lactoferrin hydrolysates were assessed for their antibacterial activities against Escherichia coli and Bacillus subtilis. At pH 3, calf rennet lactoferrin hydrolysate before (LFH) showed the highest antimicrobial activity, then pepsin LFH, while fungal rennin LFH was the least active. The calf rennet and pepsin LFH were fractionated using autofocusing and chromatographic techniques. The activity-guided fractionation of calf rennet LFH identified a potent antimicrobial peptide of 11-residues, lactoferricin B (Lf-cin B), and three other novel antibacterial peptides. The 11-residues Lf-cin B was the most potent antibacterial peptide and was isolated from both rennet and pepsin LFH. Pepsin LFH had a main antimicrobial peptide of 25-residues, which was not detected in calf rennet LFH. It could be concluded that calf rennet LFH had stronger antibacterial properties than porcine pepsin LFH. Besides, autofocusing could be used for scaling up the isolation of the potent rennet LFH peptides that would have a widespread commercial use as a natural food preservative substituting porcine pepsin digest, especially in Islamic communities.  相似文献   
769.
Starch and dextrin were phosphorylated by dry‐heating in the presence of phosphate, and their properties were examined. The phosphorylation of starch was accelerated with decreasing moisture, rising incubation temperature and prolongation of the incubation period. However, a rise in incubation temperature, and lengthened incubation period caused increased browning and degradation. A decrease in the pH from 5.5 to 3.0 resulted in a modest increase of phosphorylation, but also marked browning and degradation. When potato starch was phosphorylated at 140°C and pH 5.5 for 24 h, its phosphorus content was increased up to 3.47%, with fewer side reactions. Phosphorlylated starch and dextrin had calcium phosphate‐solubilizing abitity. Phosphorylated dextrin with 2.42% phosphorus had about half the calcium phosphate‐solubilizing ability of casein phosphopeptide (CPP). The possibility of substituting of phosphorylated starch and dextrin for CPP as a calcium phosphate‐absorption enhancing material is discussed herein.  相似文献   
770.
信息技术的进化,不可思议地降低了信息费用,急剧增加了信息利用者,制造业面临生产主导型的大量生产模式向消费者主导型的订货生产模式的迫切转换,在此时代的转换点,我们提倡“ITonMT”的设想作为制造业强化竞争力的指针,从同时具有应用IT(用IT)和提供IT的生产手段(作IT)两种立场的机床业发展出发,在此介绍实现“ITonMT”的设想的工具IT广场。  相似文献   
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