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Kenji Masumoto Tomoki Shono Shin-ichiro Takasugi Noboru Hotta Kazutaka Fujishima Yukihide Iwamoto 《Journal of electromyography and kinesiology》2007,17(5):596-604
This study aimed to examine whether walking in water produces age-related differences in muscle activity, stride frequency (SF), and heart rate (HR) response. Surface electromyography (EMG) was used to evaluate muscle activities in six older and six young subjects while they walked in water immersed to the level of the xiphoid process. The trials in water utilized the Flowmill which consists of a treadmill at the base of a water flume. The measurement of maximal voluntary contraction (MVC) of each muscle was made prior to the gait analysis. The %MVCs, which refer to the surface EMG measures, from the gastrocnemius of the older subjects were significantly lower than those of the young subjects, in every experimental condition (P<0.05). In contrast, the %MVCs from the rectus femoris (P<0.05) and the biceps femoris (P<0.001) of older subjects were significantly greater than those of young subjects in every experimental condition. Moreover, the SFs of older subjects were also significantly greater than those of young subjects (P<0.05), while the HR responses of older and young subjects were similar. In conclusion, the older subjects had increased hip musculature activity and decreased ankle plantar flexor activity while walking in water, compared with the young subjects. 相似文献
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Yasumasa Kunifuji Terumasa Nakamura Masayuki Takasugi 《Biological trace element research》1987,14(3):237-248
Cd induced changes of Zn and Cd distribution in the liver and kidneys were studied in relation to Cd metallothionein (MT)
synthesis. Wistar male rats were given CdCl2 by sc injection of .8, 1.5, and 3.0 mg Cd/kg three times a week for three weeks. Cd levels of liver and kidneys increased
with the increment of Cd dosage and 80–90% of Cd was found in the cytosol. The MT fractions contained 80–89% cytosolic Cd
in the liver and 55–75% Cd in the kidneys. Zn concentrations in the liver increased following Cd administration, But Zn in
the kidneys showed only slight increase. There was a distinct decrease of Cu concentration in the liver of the 3.0 mg group.
In contrast, Cu concentrations in the kidneys increased about three times in the .8 and 1.5 mg Cd groups, but Cu in the 3.0
mg group showed only 1.5 times increase. The changes of these metal concentrations were observed mainly in the cytosol. Non-MT-Cd
in the kidneys was maximum in the 1.5 mg group, but the 3.0 mg group showed significant decrease. In parallel with this decrease
of Cd, Cu and Zn in the kidneys showed similar decrease. When the kidneys are injured, Zn and Cu appear to leak from this
organ. 相似文献
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Went's classical experiment on the diffusion of auxin activity from unilaterally illuminated oat coleoptile tips (Went 1928), was repeated as precisely as possible. In agreement with Went's data with theAvena curvature assay, the agar blocks from the illuminated side of oat (Avena sativa L. cv. Victory) coleoptile tips had, on an average, 38% of the auxin activity of those from the shaded side. However, determination of the absolute amounts of indole-3-acetic acid (IAA) in the agar blocks, using a physicochemical assay following purification, showed that the IAA was evenly distributed in the blocks from the illuminated and shaded sides. In the blocks from the shaded and dark-control halves the amounts of IAA were 2.5 times higher than the auxin activity measured by theAvena curvature test, and in those from the illuminated half even 7 times higher. Chromatography of the diffusates prior to theAvena curvature test demonstrated that the amounts of two growth inhibitors, especially of the more polar one, were significantly higher in the agar blocks from the illuminated side than in those from the shaded side and the dark control. These results show that the basic experiment from which the Cholodny-Went theory was derived, does not justify this theory. The data rather indicate that phototropism is caused by the light-induced, local accumulation of growth inhibitors against a background of even auxin distribution, the diffusion of auxin being unaffected.Abbreviation IAA
indole-3-acetic acid 相似文献
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We have reevaluated the sequence of porcine follicle-stimulating hormone (pFSH) with more recent protein-sequencing methodology. This has led to revision of the earlier proposed sequence. As with almost all reported gonadotropin -subunits, NH2-terminal heterogeneity was found in the porcine FSH -subunit (FSH), starting with residue Phe (1), Asp (3), Gly (4), or Thr (7). In the -subunit, there were found to be at least two molecular species, starting with residue Asn (1) (minor 20%) or Cys (3) (major 80%) as NH2-terminal and ending at residue Glu (108) as COOH-terminal. The net effect of the present revisions is to increase the homology of pFSH with other reported follitropin sequences. Apparent differences in the half-cystine placements in a previous proposal for pFSH compared with other species of FSH are no longer tenable. The half-cystine placements thus remain a constant structural feature throughout the gonadotropin hormones (choriogonadotropin, follitropin, and lutropin). 相似文献
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It is often reported that an animal with spotty coat markings on its body has a tail with stripe-shaped pattern. In other various biological and chemical phenomena in/on cylinder-like domains, longitudinally periodic band patterns are observed much more often than the other non-uniform patterns. This paper mathematically explains these observations by proving that, in/on a long and narrow cylinder-like domain, any solution of reaction-diffusion system asymptotically loses its spatial dependence in the transectional/circumferential direction. 相似文献
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Fertilization of the medaka egg in 10% Ringer's solution generates a depolarization of 4 mV just before the appearance of a characteristically longer hyperpolarization (25). The depolarization appears to be the result of a nonspecific leak triggered by sperm stimulation and the amplitude of the depolarization is thought to be independent of [Ca2+ ]o (25). We have investigated the ionic dependence of this depolarization. An initial small depolarization (3–4 mV; duration, 5–8 sec) is followed by a rising phase of a spike-like depolarization in the range of 10–60 mV. The amplitude of this spike-like depolarization is propodional to log [Ca2+ ], ranging from 0.33–18 mM. Calcium antagonists, e.g. 10 mM cobalt or 10 μg/ml verapamil in 10% Ringer do not block the depolarization in the presence of 1.1 mM CaCl2 . 相似文献