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排序方式: 共有427条查询结果,搜索用时 15 毫秒
91.
This work was designed to investigate EEG indices of Internally and Externally Controlled Attention in infancy. EEG was recorded in 15 infants aged 7-8 months under three experimental conditions: (1) visual attention to a new stimulation (Externally Controlled Attention or baseline condition); (2) attention guided by internal cognitive schemata during 'anticipatory' phase of the peek-a-boo game (Internally Controlled Attention); and (3) 'reappearance' phase of the peek-a-boo game when the experimenter talked and smiled to an infant (reappearance). The relative power (RP) in 4-5 single-Hz theta sub-band increased under both phases of the peek-a-boo game. The reactive changes of 4-5 single-Hz RP at prefrontal and frontal leads under the Internally Controlled Attention condition positively correlated with the total time during which an infant was able to maintain ICA. The RP in 5-6 single-Hz theta sub-band significantly increased only under the Internally Controlled Attention condition and did not correlate with the total time of this type of attention. The results support the concept of 'Diffuse Theta-Response System' that is active during expectancy and effortfully focused attention. In contrast to theta, the RP in 6-7, 7-8, and 8-9 single-Hz bands decreased during both phases of the game. The decrease was maximal at precentral leads and most probably reflected blockage of the sensorimotor (mu) rhythm due to higher motility and muscular tension in the game situation. It is concluded that EEG is an adequate vehicle for investigation of brain mechanisms of attention and voluntary control in infants. 相似文献
92.
Auditory brain-stem potential findings in 154 healthy infants and infants with different forms of middle-ear pathological conditions (306 ears) were indicative of the inflammatory process influence on the parameters of auditory reception in most cases. The changes in the waves' forms and intraoperative morphological findings in the middle ear were correlated. Objective audiometry allows definite determination of the middle ear trouble which is important in diagnosis of latent otitis in infants who are especially prone to this disease. 相似文献
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NI Larionova IP Gladysheva IN Topchieva NF Kazanskaia 《Canadian Metallurgical Quarterly》1993,58(10):1658-1664
A classical soybean inhibitor of the Bowman-Birk type (BBI) with a copolymer of ethylene oxide and propylene oxide (PE) has been synthesized. The BBI-PE conjugate contain five covalently bound polymeric chains per one protein molecule and retains its capacity to inhibit trypsin (Ki = 10(-10) M), alpha-chymotrypsin (Ki = 7 x 10(-8) M) and human granulocyte elastase (Ki = 3 x 10(-8) M). The preservation of the antiproteinase activity in the antichymotrypsin center creates a prerequisite for the manifestation of the anticarcinogenic effect of the inhibitor. 相似文献
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IuP Solodovnikov IN Lytkina NN Filatov AV Ivanenko BE Za?tsev 《Canadian Metallurgical Quarterly》1997,40(1):31-35
Herpes simplex virus-1 (HSV-1) glycoprotein E (gE) is a multifunctional protein capable of both binding the Fc portion of IgG and mediating cell-to-cell spread of HSV-1. Here we report that the domain on gE involved in IgG binding is distinct from the domain involved in mediating cell-to-cell spread. To do this we have used five mutants of the HSV-1 strain NS: NS-gE(null), a gE deletion virus; rNS-gE(null), a gE rescued virus; NS-gE339, a gE mutant virus with a four amino acid insert at position 339; rNS-gE339, a gE rescue of NS-gE339; and NS-gE406, a gE mutant virus with the same four amino acids inserted at position 406. Using IgG coated sheep red blood cells in rosetting assays, we show that the NS-gE339 does not bind IgG, yet retains the ability to mediate normal cell-to-cell spread. These results demonstrate that the gE domain involved in IgG binding differs from the domain involved in cell-to-cell spread. 相似文献
99.
The acylated, B-ring substituted anthocyanins of Tradescantia pallida (TPA) were extracted from the leaves with acidic water, purified on a Duolite-861 resin and incorporated into a model beverage. The beverage was composed of a citrate-phosphate buffer at pH values 3.5, 4.5 or 5.5, and 15% sucrose. Comparison samples contained cyanidin-3-glucoside from blackberries and a commercial sample of enocyanin from grapes. The TPA samples were much more stable than the other two, particularly at the higher pH values as judged by pigment retention and tristimulus color readings. The extra absorption band of the TPA samples at pH 5.5 indicated the samples were well colored. Addition of tannin and/or ascorbic acid resulted in marked pigment and color loss. 相似文献
100.
SD Podymova IN Ulanova TD Bol?hakova VN Khomiakova 《Canadian Metallurgical Quarterly》1997,75(3):32-35
We have conducted a prospective study aimed to analyse contraceptive use among women seeking for legal abortion in the State University Hospital "Ma?chin dom"--Sofia. Our date demonstrate that the patients were well informed about the existing contraceptive methods. On the contrary the percentage of women-using contraception and especially those, using highly effective ones is relatively low. The patients claim the possible side effects of the high effective contraception as a reason against use. 相似文献