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排序方式: 共有324条查询结果,搜索用时 15 毫秒
1.
Ernest B. Cady Ann Lorek Yakito Takei John S. Wyatt Juliet M. Penrice A. David Edwards Donald Peebles Marzena Wylezinska Huw Owen-Reece Vincent Kirkbride Christopher E. Cooper Richard F. Aldridge Simon C. Roth Guy Brown David T. Delpy E. Osmund R. Reynolds 《Magma (New York, N.Y.)》1994,2(3):437-439
The aim of this study was to reproduce the delayed (secondary) cerebral energy failure previously described in birth-asphyxiated newborn infants and to investigate relationships between primary insult severity and the extent of the delayed energy failure. Phosphorus (31P) magnetic resonance spectroscopy (MRS) at 7 T was used to study the brains of 12 newborn piglets during an acute, reversible, cerebral hypoxic-ischemic episode which continued until nucleotide triphosphates (NTP) were depleted. After reperfusion and reoxygenation, spectroscopy was continued for 48 h. High-energy metabolite concentrations returned to near normal levels after the insult, but later they fell as delayed energy failure developed. The time integral of NTP depletion in the primary insult correlated strongly with the minimum [phosphocreatine (PCr)]/[inorganic orthophosphate (Pi)] observed 24–48 h after the insult. (Linear regression analysis gave slope –8.04 h–1; ordinate intercept=1.23;r=0.92;P<0.0001.) This model is currently being used to investigate the therapeutic potential of various cerebroprotective strategies including hypothermia. 相似文献
2.
Takekazu Ishida Kiichi Okuda Hidehito Asaoka Yukio Kazumata Kenji Noda Humihiko Takei 《Journal of Low Temperature Physics》1996,105(5-6):1165-1170
The interplane (cb) and intraplane (ab) anisotropy of untwinned YBa2 Cu307 single crystals has been investigated by means of the torque magnetometry. To extract the reversible and irreversible components, the torque was measured as a function of increasing angle as well as decreasing angle. The interplane irreversible torque irr shows two-fold peaks at c =90 ° and270 ° (of half width11 ° at77 K) due to the well-known intrinsic interplane pinning. A novel intrinsic pinning has been discovered in the intraplane irreversible torque, i.e., irr shows four-fold peaks of half width20° at77 K when a =0 °, 90 °, 180 ° and270 °. We argue that the intrinsic intraplane pinning comes from the four-fold nature of the gap parameter. 相似文献
3.
Yanyan Hou Satoshi Arai Yoshiaki Takei Atsushi Murata Shinji Takeoka 《Science and Technology of Advanced Materials》2016,17(1):293-299
Ca2+ distribution is spatially and temporally non-uniform inside cells due to cellular compartmentalization. However, Ca2+ sensing with small organic dyes, such as fura-2 and fluo-4, has been practically applied at a single cell level where the averaged signal from freely diffusing dye molecules is acquired. In this study, we aimed to target azide-functionalized fura-2 (N3-fura-2) to a specific site of subcellular compartments to realize focal Ca2+ sensing. Using scAVD (single-chain avidin)–biotin interaction and a copper-free click reaction system, we linked N3-fura-2 to specifically-targeted scAVD protein fused with a red fluorescent protein mCherry, so that Ca2+ sensors conjugated with four N3-fura-2 dyes with dibenzocyclooctyne (DBCO)-PEG4-biotin as a linker were generated at subcellular compartments in living cells. In cytoplasm, N3-fura-2 showed a prolonged retention period after binding to scAVD. Furthermore, the reacted N3-fura-2 was retained inside cells even after free dyes were washed out by methanol fixation. When scAVD was overexpressed on endoplasmic reticulum (ER) membranes, N3-fura-2 was accumulated on ER membranes. Upon histamine stimulation, which increases cytosolic Ca2+ concentration, ER-localized N3-fura-2 successfully sensed the Ca2+ level changes at the cytosolic side of ER membrane. Our study demonstrated specific targeting of N3-fura-2 to subcellular compartments and the ability of sensing focal Ca2+ level changes with the specifically targeted Ca2+ sensors. 相似文献
4.
Takayuki Takei Hideki Nakahara Sadao Tanaka Hiroto Nishimata Masahiro Yoshida Koei Kawakami 《Journal of materials science. Materials in medicine》2013,24(10):2479-2487
We previously developed chitosan cryogels from chitosan-gluconic acid conjugate without using toxic additives for wound care. In this study, we improved physiological characteristics of the previous cryogels by incorporating poly(vinyl alcohol) that also form cryogels. Mechanical strength of the cryogels was more than two times higher than that of the previous cryogels. Furthermore, the incorporation of poly(vinyl alcohol) enhanced water retention and resistance to degradation of the gels by lysozyme. The cryogels retained the favorable biological properties of the previous cryogels that they accelerate infiltration of inflammatory cells into wound sites. Time period for repairing 50 % of initial area of partial-thickness skin wound treated with the cryogels (4.0 ± 1.1 days) was shorter than those with gauze (6.5 ± 0.3 days) or a commercial hydrogel dressing (5.7 ± 0.3 days). Finally, we confirmed that incorporation of basic fibroblast growth factor into the cryogels was effective to further accelerate wound healing (2.7 ± 1.0 days). These results demonstrate that the cryogels in this study are promising for wound care. 相似文献
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7.
Naohiro Gotoh Shino Miyake Hiroko Takei Kumi Sasaki Saori Okuda Michitaka Ishinaga Shun Wada 《Food Analytical Methods》2011,4(4):525-530
We developed a simple method for quantification of the peroxide value (PV) in colored lipids on the basis of the reaction
between triphenylphosphine (TPP) and oxidized oil to afford triphenylphosphineoxide (TPPO). Diphenylphosphineoxide (DPPO)
was employed as internal standard. The formed TPPO was analyzed by high-pressure liquid chromatography–UV spectroscopy with
absorption at 260 nm. The conditions that gave the highest correlative calibration curve between the peak area on the chromatogram
and peroxide value were identified: the optimum TPP–oxidized oil mix ratio, reaction temperature, and reaction time were found
to be 2:1, 40 °C, and 30 min, respectively. Linear calibration curves, passing through the origin, were obtained for PV versus
TPPO and TPPO versus DPPO. The quantification limit for this method was 2.01 pmol hydroperoxyl group, which corresponds to
a PV value of 0.2 meq/kg in a 10-mg oil sample. This method was used to measure the PV in colored fats and oils or lipids
extracted from dark meat and processed food containing a coloring agent. Though the official method could not measure the
PVs in the colored lipids, the method proposed here, which uses an inexpensive chemical reagent and machine, could. The developed
method could play an important role for food quality control. 相似文献
8.
9.
Measurement of particle concentration in powder coating process using capacitance computed tomography and wavelet analysis 总被引:1,自引:0,他引:1
Capacitance computed tomography techniques were used to visualize particles movement in the draft tube of a spouted fluidized bed for the coating process of drug production. A total of 512 frames images of the particle concentration distribution were obtained at 10-millisecond intervals over a coating time of 5 min using a capacitance computed tomography system. The three-dimensional capacitance CT images (time and two-dimensional space images) were decomposed to wavelet time and space levels to extract the dominant particle distribution feature using three-dimensional discrete wavelet multiresolution at different coating times. As a result, the time and space dominant particle distribution with a specific frequency level can be visualized. 相似文献
10.
Kotaro Hama Yuko Fujiwara Masashi Morita Fumiyoshi Yamazaki Yuko Nakashima Shiro Takei Shigeo Takashima Mitsutoshi Setou Nobuyuki Shimozawa Tsuneo Imanaka Kazuaki Yokoyama 《Lipids》2018,53(1):85-102
ABCD1 is a gene responsible for X‐linked adrenoleukodystrophy (X‐ALD), and is critical for the transport of very long‐chain fatty acids (VLCFA) into peroxisomes and subsequent β‐oxidation. VLCFA‐containing lipids accumulate in X‐ALD patients, although the effect of ABCD1‐deficiency on each lipid species in the central nervous system has not been fully characterized. In this study, each phospholipid and lysophospholipid species in Abcd1‐deficient mice brains were profiled by liquid chromatography‐mass spectrometry. Among the phospholipid and lysophospholipid species that are significantly more enriched in Abcd1‐deficient mice brains, VLCFA were present in 75, 15, 5, 4, and 1 species of phosphatidylcholine, phosphatidylethanolamine, sphingomyelin, lysophosphatidylcholine, and lysophosphatidylethanolamine, respectively. Most VLCFA were incorporated at the sn‐1 position of phosphatidylcholine and phosphatidylethanolamine. Among the phospholipid species that are significantly less enriched in Abcd1‐deficient mice brains, odd‐numbered saturated or mono‐unsaturated fatty acyl moieties are contained in all phosphatidylcholine species. In addition, a number of phosphatidylglycerol, phosphatidylinositol, and phosphatidylserine species contained highly unsaturated fatty acyl moieties. Intriguingly, 44:1 phosphatidylcholine with VLCFA was mainly distributed in the gray matter, such as the cortex, but not in the white matter in the cerebrum and cerebellum. These results show that ABCD1‐deficiency causes metabolic alternation of long‐chain fatty acids and VLCFA. Moreover, our results imply a molecular mechanism for the incorporation of saturated or monounsaturated VLCFA into the sn‐1 position of phospholipids, and also indicate that the distribution of phospholipids with VLCFA may correlate with the development of X‐ALD. 相似文献