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991.
992.
To explore the relationship between the processing of melodic and rhythmic patterns in speech and music, we tested the prosodic and musical discrimination abilities of two "amusic" subjects who suffered from music perception deficits secondary to bilateral brain damage. Prosodic discrimination was assessed with sentence pairs where members of a pair differed by intonation or rhythm, and musical discrimination was tested using musical-phrase pairs derived from the prosody of the sentence pairs. This novel technique was chosen to make task demands as comparable as possible across domains. One amusic subject showed good performance on both linguistic and musical discrimination tasks, while the other had difficulty with both tasks. In both subjects, level of performance was statistically similar across domains, suggesting shared neural resource for prosody and music. Further tests suggested that prosody and music may overlap in the processes used to maintain auditory patterns in working memory. 相似文献
993.
JG Cock AD Tepper E de Vries WJ van Blitterswijk J Borst 《Canadian Metallurgical Quarterly》1998,273(13):7560-7565
CD95 is a potent inducer of apoptosis. It activates the caspase cascade, but also induces ceramide (Cer) production, reportedly involving acid sphingomyelinase (aSMase) activity. A role for Cer as a second messenger for apoptosis induction was proposed, based on the finding that synthetic Cer analogues can induce cell death. We have tested whether aSMase is required for 1) apoptosis induction and 2) Cer production by CD95. For this purpose, we have used cultured Niemann-Pick disease (NPD) lymphoid cells with a defined mutation (R600H) in the aSMase protein. Despite their inherited deficiency of aSMase, we found that these cells readily undergo apoptosis upon CD95 stimulation. After retrovirus-mediated gene transfer of the aSMase cDNA, the transduced (i.e. "corrected") NPD cells showed neither increased levels of apoptosis nor altered kinetics of caspase-8 and caspase-3 activation and apoptosis induction as compared with empty vector-transduced cells. The slow sustained elevation of Cer levels in response to CD95, which we have previously documented for Jurkat T cells (Tepper, A. D., Boesen-de Cock, J. G. R., de Vries, E., Borst, J., and van Blitterswijk, W. J. (1997) J. Biol. Chem. 272, 24308-24312), was similarly found in NPD cells. Moreover, the kinetics of Cer formation remained unaffected after aSMase transduction. These results indicate that this Cer does not result from aSMase activity. We conclude that aSMase is not required for and does not facilitate CD95-mediated apoptosis and that it is not responsible for the late Cer response. 相似文献
994.
995.
Clinical and physiological examinations of 76 women in the postmenopause revealed in 64 of them the typical form of the climacteric syndrome, characterized by not only typical symptoms ("flushes", increased exudation, headaches, etc.), but also by various emotional vegetative disturbances detected at profound clinical neurological examination of the autonomic nervous system and the emotional sphere. Individual hormone therapy was associated with an appreciable alleviation of all psychovegetative disorders: "flushes", exudation, irritability, arterial hypertension, severity of vegetative dystonia, hysterical stigmata. 相似文献
996.
小隐孢子虫(Cryptosporidium parvum)污染是对水工程的一个挑战也威胁到公众健康.在此项研究中,我们开发了一种细胞培养-定量PCR分析法来评估消毒后小隐孢子虫的活性.我们用这种方法对水工程中多种消毒法包括低压紫外光(LP-UV),臭氧,混合氧化剂(MIOX),氯气进行评估.证实该检测方法是可信和敏感的,最低能检测到一个感染卵囊.有效的卵囊消毒(灭活率>2log10 units)是采用LP-UV(20 mJ/cm2)或2 mg臭氧/公升(10分钟).MIOX和氯气消毒卵囊效果最差(灭活率<0.1 log10 unit).这些结果证实了MIOX对小隐孢子虫消毒的无效性.该检测方法是对饮用水和循环水消毒系统有效的评估方法. 相似文献
997.
Few‐Layer MoSe2 Nanosheets with Expanded (002) Planes Confined in Hollow Carbon Nanospheres for Ultrahigh‐Performance Na‐Ion Batteries
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Hui Liu Hong Guo Beihong Liu Mengfang Liang Zhaolin Lv Keegan R. Adair Xueliang Sun 《Advanced functional materials》2018,28(19)
Sodium‐ion batteries (SIBs) are considered as a promising alternative to lithium‐ion batteries, due to the abundant reserves and low price of Na sources. To date, the development of anode materials for SIBs is still confronted with many serious problems. In this work, encapsulation‐type structured MoSe2@hollow carbon nanosphere (HCNS) materials assembled with expanded (002) planes few‐layer MoSe2 nanosheets confined in HCNS are successfully synthesized through a facile strategy. Notably, the interlayer spacing of the (002) planes is expanded to 1.02 nm, which is larger than the intrinsic value of pristine MoSe2 (0.64 nm). Furthermore, the few‐layer nanosheets are space‐confined in the inner cavity of the HCNS, forming hybrid MoSe2@HCNS structures. When evaluated as anode materials for SIBs, it shows excellent rate capabilities, ultralong cycling life with exceptional Coulombic efficiency even at high current density, maintaining 501 and 471 mA h g?1 over 1000 cycles at 1 and 3 A g?1, respectively. Even when cycled at current densities as high as 10 A g?1, a capacity retention of 382 mA h g?1 can be achieved. The expanded (002) planes, 2D few‐layer nanosheets, and unique carbon shell structure are responsible for the ultralong cycling and high rate performance. 相似文献
998.
PM Martha AD Rogol LM Carlsson N Gesundheit RM Blizzard 《Canadian Metallurgical Quarterly》1993,77(2):452-457
Previous studies have provided compelling evidence that GH secretion increases transiently during midpuberty in normally growing children. Although it is likely that the increase in GH production serves a primary role in generating the pubertal growth spurt, such a conclusion necessarily assumes that other essential "down-stream" components of the GH axis responsible for mediating the effects of GH remain unchanged. To investigate this concept, we assessed longitudinally another important component of the endogenous GH axis, the serum GH-binding protein (GHBP)/receptor system, in a cohort of 11 normal boys as they matured through normal puberty. At 4-month intervals over 4.0-5.1 yr, 24-h serum GH concentration profiles and serum GHBP activity were evaluated. Serum GHBP levels varied over a more than 12-fold range (40-504 pmol/L) among all subjects. However, the values for individual subjects consistently varied within more narrow limits. The coefficient of variation for values from all subjects was 51% compared to the mean intrasubject coefficient of variation of only 30% (P < 0.05). Although the highest GHBP level (all subjects) was 12.6-fold greater than the lowest, the mean intrasubject range was only 3.1 +/- 0.5-fold (P < 0.05). The overall mean serum GHBP level correlated directly with the overall mean body mass index (r = 0.69; P = 0.018), but correlated inversely with the mean 24-h GH concentration (r = -0.61; P < 0.05). There was no significant increase in the GHBP level during puberty. However, because mean 24-h GH concentrations did increase during midpuberty, the data suggest that an increase in the relative amounts of free vs. bound GH develops during the period of the pubertal growth spurt. These data indicate that serum GHBP levels are regulated in individual children within much more narrow limits than those present in the larger population and do not undergo the dramatic changes during puberty typical of GH secretion and linear growth velocity. As a consequence, alterations may develop in the relative amounts of free vs. bound GH present in serum during the midpubertal years compared to those present during either the prepubertal or postpubertal periods. The majority of the known age-related increase in serum GHBP levels probably occurs before the period of active pubertal development. These findings strengthen further the concept that the midpubertal changes in GH secretion serve a primary role in generating the growth spurt.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
999.
Taxonomies of SOFC material and manufacturing alternatives 总被引:4,自引:0,他引:4
Material and manufacturing alternatives for solid oxide fuel cells are listed and analyzed. Specifically, four categories of anode materials, five categories of cathode materials, four categories of electrolytes, and three categories of interconnect materials are presented. Design considerations including operating temperatures and compatibilities among stack materials are also highlighted. Similarly, stack manufacturing options are separated into seven categories and developed into process sequences based on the number and type of firing steps. This work is intended to facilitate material and manufacturing assessments through the consideration of the variety of alternatives prior to capital investment for wide-scale production. 相似文献
1000.