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61.
DiPietro Janet A.; Caulfield Laura; Costigan Kathleen A.; Merialdi Mario; Nguyen Ruby H. N.; Zavaleta Nelly; Gurewitsch Edith D. 《Canadian Metallurgical Quarterly》2004,40(3):445
Longitudinal neurobehavioral development was examined in 237 fetuses of low-risk pregnancies from 2 distinct populations-Baltimore, Maryland, and Lima. Peru-at 20. 24. 28. 32, 36. and 38 weeks gestation. Data were based on digitized Doppler-based fetal heart rate (FHR) and fetal movement (FM). In both groups. FHR declined while variability, episodic accelerations, and FM-FHR coupling increased, with discontinuities evident between 28 and 32 weeks gestation. Fetuses in Lima had higher FHR and lower variability, accelerations, and FM-FHR coupling. Declines in trajectories were typically observed 1 month sooner in Lima, which magnified these disparities. Motor activity differences were less consistent. No sex differences in fetal neurobehaviors were detected. It is concluded that population factors can influence the developmental niche of the fetus. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
62.
The differential effectiveness of group psychotherapy was estimated in a meta-analysis of 111 experimental and quasi-experimental studies published over the past 20 years. A number of client, therapist, group, and methodological variables were examined in an attempt to determine specific as well as generic effectiveness. Three different effect sizes were computed: active versus wait list, active versus alternative treatment, and pre- to posttreatment improvement rates. The active versus wait list overall effect size (0.58) indicated that the average recipient of group treatment is better off than 72% of untreated controls. Improvement was related to group composition, setting, and diagnosis. Findings are discussed within the context of what the authors have learned about group treatment, meta-analytic studies of the extant group literature, and what remains for future research. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
63.
WL Flejter D Finlinson S Root W Nguyen AR Brothman D Viskochil 《Canadian Metallurgical Quarterly》1996,66(3):276-280
Ring (19) chromosomal mosaicism has been identified in a 14-month-old girl referred for cytogenetic evaluation due to microcephaly and developmental delay with autistic-like mannerisms. An analysis of her peripheral blood lymphocytes showed a 46,XX,r(19) cell line in 119/121 of cells examined. Of the two remaining cells, one had a normal female chromosome complement and the other showed loss of one of the chromosome 19 homologs. Further analysis by fluorescence in situ hybridization using an all human telomere probe showed the presence of a single hybridization signal on the r(19) chromosome. Subsequent cytogenetic characterization of cells derived from the patient's phenotypically normal mother also demonstrated the presence of a ring 19 chromosome in 4/100 cells. The remaining cells had a normal female chromosome complement. These findings represent the first reported case of familial ring 19 mosaicism. The cytogenetic and clinical findings in these two individuals are discussed in relation to six previously reported cases of de novo ring chromosome 19 mosaicism. 相似文献
64.
Optimization of a Ductile-Particle-Toughened Ceramic 总被引:2,自引:0,他引:2
The nature of the interfacial bond has a major effect on the degree of toughening that can be achieved in a ductile-particle-reinforced ceramic-matrix composite. The effect of variation of oxygen partial pressure during fabrication on the bonding in an alumina-nickel composite has been investigated. Calculations suggest that wetting of alumina by nickel should always be accompanied by spinel (NiAl2 O4 formation. A range of microstructures within a single specimen have been produced, however, indicating that wetting occurs more rapidly than spinel formation and that reduction of oxygen partial pressure during the hot-pressing process can prevent spinel formation after wetting has occurred. Within this specimen, interfaces that have been formed under nonwetting conditions or conditions under which spinel formation has occurred are weak, whereas wetting without spinel formation produces chemically strengthened and mechanically interlocked interfaces that lead to crack interaction with the metallic particles and a higher toughening increment than for other microstructures. Subsequent specimens fabricated from preconsolidation-heat-treated powder exhibit favorable microstructures throughout, are tougher, and show more-desirable resistance-curve behavior in double-cantilever-beam tests than specimens produced from unreacted powder. 相似文献
65.
The preparation of a SiC coating on a carbon fiber surface using a sol-gel mixture of tetraethyl orthosilicat (TEOS) and phenolic resin was studied. FTIR and SEM investigations indicated that the SiC coating can be formed by carbothermal reduction of the sol-gel mixture at 1420°C for 15–20 min in an argon atmosphere. TGA of the coated fiber was also performed, showing that the SiC coating improves the thermooxidative stability of the carbon fiber. With the thickness of the obtained coating of 0.47 μm using a C/Si ratio of 4, this treatment does not affect the carbon fiber strength. 相似文献
66.
67.
H. Launay S. Loridant D.L. Nguyen A.M. Volodin J.L. Dubois J.M.M. Millet 《Catalysis Today》2007,128(3-4):176-182
New vanadium oxide supported on mesoporous silica catalysts for the oxidation of methane to formaldehyde were investigated by infrared and Raman spectroscopies to identify and characterize the molecular structure of the most active and selective catalytic sites. In situ and operando experiments have been conducted in order to understand the redox and hydroxylation/dehydroxylation processes of the vanadium species. (SiO)2VO(OH) species were identified in these catalysts in reaction conditions and shown to undergo a deprotonation at 580 °C under vacuum, leading to a site giving a photoluminescence band at 550 nm attributed to reverse radiative decay from the excited triplet state:
(V4+–O−)* (V5+O2−). An activation mechanism of vanadium monomeric species with electrophilic oxygen species is proposed. 相似文献
68.
Integrated Microfluidic CustomArray Device for Bacterial Genotyping and Identification 总被引:2,自引:0,他引:2
69.
Evidence from 3 experiments reveals interference effects from structural relationships that are inconsistent with any grammatical parse of the perceived input. Processing disruption was observed when items occurring between a head and a dependent overlapped with either (or both) syntactic or semantic features of the dependent. Effects of syntactic interference occur in the earliest online measures in the region where the retrieval of a long-distance dependent occurs. Semantic interference effects occur in later online measures at the end of the sentence. Both effects endure in offline comprehension measures, suggesting that interfering items participate in incorrect interpretations that resist reanalysis. The data are discussed in terms of a cue-based retrieval account of parsing, which reconciles the fact that the parser must violate the grammar in order for these interference effects to occur. Broader implications of this research indicate a need for a precise specification of the interface between the parsing mechanism and the memory system that supports language comprehension. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
70.
W Feng RC Ribeiro RL Wagner H Nguyen JW Apriletti RJ Fletterick JD Baxter PJ Kushner BL West 《Canadian Metallurgical Quarterly》1998,280(5370):1747-1749