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1.
During the period April 1962 to April 1963, 28 newborn infants, 7 stillborns, and 21 children from 4 to 15 years of age were examined for emission of gamma activity in a low-background, high-sensitivity, total-body counting facility. The 21 children contained traces of combined Zr(95) and Nb(95), Ru(103), (106), and Cs(137) in addition to the normal K(40). The greatest concentration of Cs(137) observed was 80 picocuries per kilogram of body weight, or about 4 percent of the natural K(40) radioactivity. Four of the seven stillborns, each counted for 10 hours, shoWed K(40) and traces of Zr(95), Nb(95), and Ru(103), (106). The ratios of Zr(95) to Nb(95) were lower in the stillborns than in their placentas which suggested placental discrimination against Zr(95). The ratios of Cs(137) to K(40) were lower in infants than in children or adults. Thyroid glands obtained atautopsy from 24 infants during April to September 1962 contained no detectable radioiodine ( less than 30 pc). 相似文献
2.
Human infants begin to acquire their native language in the first months of life. To determine which brain regions support language processing at this young age, we measured with functional magnetic resonance imaging the brain activity evoked by normal and reversed speech in awake and sleeping 3-month-old infants. Left-lateralized brain regions similar to those of adults, including the superior temporal and angular gyri, were already active in infants. Additional activation in right prefrontal cortex was seen only in awake infants processing normal speech. Thus, precursors of adult cortical language areas are already active in infants, well before the onset of speech production. 相似文献
3.
Depression in infant monkeys separated from their mothers 总被引：2，自引：0，他引：2
The mothers of four pigtail (Macaca nemestrina) infants living in a group were removed for 4 weeks. All infants reacted initially with agitation. Three of the four infants then became severely depressed. The depression lasted about a week and was strikingly similar to the "anaclitic depression" of human infants who lost their mothers. When they were reunited, all four dyads showed a marked and prolonged intensification of the mother-infant relationship. 相似文献
4.
Having repeatedly retrieved an object from a location, human infants tend to search the same place even when they observe the object being hidden at another location. This perseverative error is usually explained by infants' inability to inhibit a previously rewarded search response or to recall the new location. We show that the tendency to commit this error is substantially reduced (from 81 to 41%) when the object is hidden in front of 10-month-old infants without the experimenter using the communicative cues that normally accompany object hiding in this task. We suggest that this improvement is due to an interpretive bias that normally helps infants learn from demonstrations but misleads them in the context of a hiding game. Our finding provides an alternative theoretical perspective on the nature of infants' perseverative search errors. 相似文献
5.
Human milk fat (HMF) is the component that supplies the highest fraction of the infant's required dietary energy. Other sources of fat are necessary and crucial for infants while the breastfeeding is not possible, desirable or sufficient. There is enough scientific evidence that suggests the composition and distribution of the fatty acids affect the absorption of the fat in infants greatly, which influences the growth and health of infants. However, the composition and distribution of the fatty acids in cer... 相似文献
6.
微生态制剂联合非营养性吸吮对早产儿黄疸的干预作用 总被引：1，自引：0，他引：1
目的观察早期应用微生态制剂联合非营养性吸吮对早产儿黄疸的干预效果。方法60例需经鼻胃管喂养的早产适于胎龄儿随机分成治疗组和对照组,各为30例。对照组予常规支持治疗,治疗组在此基础上予微生态制剂联合非营养性吸吮。测定两组早产儿生后第1、4、7、14天血清胆红素水平,并记录高胆红素血症发生例数和黄疸持续时间。结果与对照组相比,治疗组早产儿生后第4、7、14天血清胆红素水平明显降低（P〈0．01）,高胆红素血症发生率明显减少（23．3%vs50．0％,P〈0．05）,黄疸持续时间明显缩短[（8．34±1．60）vs（12．14±1．90）,P〈0．01]。结论早期应用微生态制剂联合非营养性吸吮可有效降低早产儿高胆红素血症发生率,缩短黄疸持续时间。 相似文献
7.
Manipulated infant rats respond to cold with depletion of adrenal ascorbic acid (AAA) significantly earlier than nonmanipulated infants. The study discussed in this report examined the critical period for infantile manipulation on the depletion of AAA. It was found that infant rats manipulated immediately following birth exhibited significant AAA depletion, whereas infants manipulated later did not exhibit depletion. 相似文献
8.
Data from two experiments show that the duration of visual fixation of solid objects by infants aged 6 to 20 weeks varies as a function of object distance between 30 and 90 centimeters. There was no characteristic habituation of fixation of an object at 90 centimeters but there was a marked increase in fixation time when objects were advanced to 30 centimeters (experiment 1). A linear decline in fixation times occurred as the object distance increased from 30 to 90 centimeters with the real size and the angular size of the object held constant (experiment 2). No evidence for visual size constancy in young infants was obtained by this method. 相似文献
9.
Infants prefer to look at an array of objects that corresponds in number to a sequence of sounds. In doing so, infants disregard the modality (visual or auditory) and type (object or event) of items presented. This finding indicates that infants possess a mechanism that enables them to obtain information about number. 相似文献
10.
Infant responses to impending collision: optical and real 总被引：2，自引：0，他引：2
Twenty-four infants ranging in age from 2 to 11 weeks responded to symmetrically expanding shadows, which optically specify an approaching object, with an integrated avoidance response and upset. This response did not occur for asymmetrically expanding shadows nor for contracting shadows that specify an object on a miss path and a receding object. The response was observed in all the infants regardless of age, and the addition of kinetic depth information to the displays did not increase the intensity or likelihood of the response. In a second experiment, seven infants defensively reacted to the approach of a real object except when it was on a miss path. 相似文献
11.
Sixteen-month-old infants (N = 83) rationally used sparse data about the distribution of outcomes among agents and objects to solve a fundamental inference problem: deciding whether event outcomes are due to themselves or the world. When infants experienced failed outcomes, their causal attributions affected whether they sought help or explored. 相似文献
12.
Prelinguistic infants recognized structural correspondences in acoustic and optic properties of synchronized, naturally spoken disyllables, but did so only when they were looking to their right sides. This result suggests that intermodal speech perception is facilitated by rightward orientation of attention and subserved by the left hemisphere. 相似文献
13.
Isolation and propagation of a human enteric coronavirus 总被引：6，自引：0，他引：6
Coronavirus-like particles were found by electron microscopy in stools from infants with necrotizing enterocolitis. Stool samples from these infants as well as control specimens were passaged in cultures of human fetal intestinal organs. Two samples yielded virus-like particles and these have now been passaged 14 times (HEC 14). Gradient-purified HEC 14 strains had typical coronavirus morphology on electron microscopy and contained five major proteins with molecular sizes ranging from 190 to 23 kilodaltons. Infants with necrotizing enterocolitis developed specific antibody to the viral antigens between the acute and convalescent stages of the disease, as shown by examining serum specimens by single radial hemolysis, immunoenzymatic assay, and Western immunoblotting. No cross-reactivity was shown with other coronavirus strains tested, or with the newly isolated viruses of the Breda-Berne group, responsible for calf or horse diarrhea. 相似文献
14.
Effects of brief separation from mother on rhesus monkeys 总被引：2，自引：0，他引：2
To summarize, data on the course of development of mother-infant relations in rhesus monkeys have been presented; a method for teasing apart the relative roles of mother and infant in causing changes or differences in the interaction described; and the complexity of the social nexus, within which the relationship is set, stressed. When the mother is removed for a few days, the infant calls a great deal at first and then shows depressed locomotor and play activity. These symptoms may last for a month after the mother's return. Simple tests given 6 months and even 2 years later strongly suggest that the differences (between infants that have had such a separation experience and infants that have not) are persistent. Are these data relevant to the human case? The rhesus monkey has no verbal language and a much less complex social development than man. Furthermore, its social environment is quite different from that found in any human culture. Parallels between monkey and man must therefore be scrutinized carefully before being used as a basis for generalization. But the facts show that a brief separation experience produces in rhesus monkey infants symptoms that are very similar (except for the apparent absence of a "phase of detachment" on reunion) to those in human infants (25). While age of separation, within the rather narrow limits used here, was a variable of minor importance, the effects of the separation varied, as in the human case, with the length of the separation experience and the sex of the infant. Differences in the techniques of experimenters, as well as differences in the species, prevent precise comparisons of the roles of the mother-infant relationships; nevertheless, the nature of the relationship appears to be an important variable in both monkey and man. There would seem, therefore, to be strong reasons for thinking that we are dealing with comparable phenomena. If that is the case, the fact that monkeys function at a simpler conceptual level than man limits the complexity of the explanatory hypotheses necessary in the human case. In addition, the finding that such a brief separation experience, involving removal of the mother but no exposure to a strange environment, can produce effects lasting for months or years in rhesus monkeys strengthens the evidence that long-term effects may occur also in man. Finally, this analysis provides bases for attempts to predict individual differences in the effects of a period of separation on rhesus infants, and the parallels with man suggest that examination of the same variables in the human case would be worthwhile. 相似文献
15.
目的：总结重症婴儿室间隔缺损(VSD)的外科治疗经验。方法：全组61例,术前均有反复感染、缺氧发作、营养不良、肺动脉高压和(或)心功能不全等的情况。做好抗感染、氧疗、降肺压、抗心力衰竭、营养支持等充分术前准备后行心内直视手术,均用补片修补室缺。结果：全组死亡2例,生存59例中低心排综合征3例,肺动脉高压危象4例,严重肺部感染6例,血气胸及痰堵导致肺叶不张各2例,拔管后窒息再插管2例,严重心律失常2例,VSD残余分流1例。结论：婴儿室间隔缺损伴有反复感染、缺氧发作、营养不良、肺动脉高压和(或)心功能不全等宜及早手术治疗,提高手术技巧和加强围术期处理是治疗成功的关键。 相似文献
16.
Development of sensitivity to pictorial depth 总被引：1，自引：0，他引：1
Sensitivity to static pictorial information for depth develops between 22 and 26 weeks of age. When conflicting binocular and surface-texture information was minimized, 26- to 30-week-old infants directed their reaching to the apparently closer side of a photograph of a window rotated in depth. Younger infants, from 20 to 22 weeks of age, did not direct their reaching to the pictorially nearer side of the display but did reach with a high degree of directionality when presented with a real window rotated in depth. 相似文献
17.
L H Hempelmann 《Science (New York, N.Y.)》1968,160(824):159-163
The incidence of thyroid carcinoma and of clinically palpable thyroid nodules is compared in three groups of individuals many years after exposure to ionizing radiation in childhood or infancy. The estimated mean cumulative doses to the thyroid gland ranged from 20 rad in the Ann Arbor series irradiated with x-rays as infants for thymic enlargement upward to 1225 rad of mixed radiation (including that from ingested radioiodine) in the Marshallese children. Intermediate between these extremes is the high-risk subgroup in the Rochester series of persons irradiated for thymic enlargement; they received an estimated mean thyroid dose of 335 rad. A plot of the incidence of thyroid nodularity against the total cumulative thyroid dose gives what could be a linear dose response with no threshold or, at least, a threshold below 20 rad. The risk of developing carcinoma in the three studies ranges from 0 to 5.5 cases and that for nodularity 38 to 52 cases per 106 persons exposed per rad (thyroid dose) per year. There is evidence dence from animal experimentation that the biologically effective dose in the case of the Marshallese would have been considerably lower than the cumulative physical dose; hence, the dose response might actually be curvilinear at least in the higher dose range. In view of the uncertainties regarding dose and the assumptions made in my study, the risk values may not be exact; however, these values reflect the trends regarding risks estimated from the best available data in man. Furthermore, the estimated risk values apply only if radiation exposure occurred in childhood. 相似文献
18.
Behavioral development after forelimb deafferentation on day of birth in monkeys with and without blinding 总被引：1，自引：0，他引：1
Four infant monkeys underwent somatosensory deafferentation of both forelimbs within hours after birth. Ambulation, climbing, and reaching toward objects developed spontaneously in each case. Thumb-forefinger prehension could be trained by operant shaping methods. Two infants deafferented at birth and blinded by eyelid closure were retarded in motor development by only 1 to 2 weeks. Results indicate that topographic sensory feedback and autogenetic spinal reflexes are not necessary after birth for the development of most types of movement performed by the forelimb musculature in monkeys. 相似文献
19.
M A Taylor 《Science (New York, N.Y.)》1969,164(880):723-724
From a review of the records of schizophrenic women whose psychotic symptoms were associated with pregnancy, it was found that those who had developed a psychosis within 1 month of conception delivered only live female infants. A predominance of males was born to 13 women who became psychotic during the first month after delivery. These observations are interpreted as consistent with a theory that schizophrenia is associated with plasma factors which interact with the fetus and provide the basis for a higher fetal mortality. 相似文献
20.
Helmuth L 《Science (New York, N.Y.)》2000,289(5479):521-522
On page 628, neuroscientists report that painful stimuli delivered to rats shortly after birth permanently rewire the spinal cord circuits that respond to pain. Not only do the circuits contain more axons, but the axons extend to more areas of the spinal cord than they normally would. The results should help convince skeptics of the importance of managing pain in human infants. 相似文献