RESUMEN
Objective: To get a general estimation of the pneumatic system in ventilators and supply technical assistance for screening and removing the faults of pneumatic component. Methods: Pneumatic system of three kinds of ventilators, Sevro-i/s, Rapheal XTC and PB840 were analyzed and the differences of the three pneumatic systems were compared. Results:Known the construct and differences of pneumatic system. Conclusion: Pneumatic system is the major component of ventilator, and the analysis of the pneumatic component is benefited for the common troubleshooting of ventilators.
RESUMEN
ObjectiveTo explore the role of psychological capital in psychological stress and mental maladjustment in recruits.Methods405 recruits were sampled and investigated using the psychological stress selfevaluation test( PSET),the psychological capital questionnaires(PCQ),and military mental maladjustment scale (MMMS).ResultsPsychological stress had significant positive correlation with each factor of mental maladjustment ( r =0.164 ～ 0.438,P ＜ 0.01 ),and psychological capital had significant negative correlation with each factor of mental maladjustment ( r=-0.312 ～ -0.463,P＜ 0.001 ).The hierarchical regression analysis indicated that psychological capital,confidence,hoping,resiliency and optimism had the positive prediction of all the four factors of mental maladjustment,the variance contribution rates were 27.2％,20.1％,25.8％ and 15.9％,respectively; the main effect of psychological capital(β1 =-0.406,P＜0.01 ;β2 =-0.351,P＜0.01 ) and psychological stress(β1 =0.304,P ＜ 0.01 ;β2 =0.267,P ＜ 0.01 ) on recruits'behavioral problem and interpersonal relationship maladjustment was significant,the interaction effect of psychological capital and psychological stress on recruits' behavioral problem (β =- 0.098,P ＜ 0.05 ) and interpersonal relationship maladjustment (β =- 0.087,P ＜ 0.05 ) was significant.ConclusionPsychological capital is a moderator in interaction between mental maladjustment and psychological stress.The PCQ score may predict the variation of recruits'mental status.
RESUMEN
BACKGROUND: Environment pollution due to lead is severe day by day,and the lead-induced developmental toxicity of central nervous system is prominent.OBJECTIVE: To observe the effect of lead at low exposure level on neurobehavioral function of preschool children and provide basis for preventing childhood behavior disorders.DESIGN: Sampling survey.SETTING: Department of Children and Adolescent Health, Public Health College, Sun Yat-sen University.PARTICIPANTS: Totally 211 children of 4-6 years (109 boys and 102girls) were enrolled from a kindergarten of a populated area of Zhuhai City by randomized cluster sampling from September to October 2004.METHODS: 20 mL peripheral blood of finger tip was collected. Blood lead was determined with graphite stove atomic absorption spectrometry.According to the amount of blood lead, the children were divided into high blood lead exposure group (＞100μg/L) and low blood lead exposure group (＜100μg/L). Furthermore, they were also assigned into ＜50 μg/L group, 50μg/L- group, 100μg/L- group, 150 μg/L- group, 250- μg/L group. Achenbach's Child Behavior Checklist (CBCL) and self-designed questionnaire (composed of possibly effective factor on children's neurobehavioral function, such as age, sex, cultivation, family background and so on) were applied, filled by their parents under the instruction of professional staffs. Results and blood lead value were analyzed with first order correlation and multiple factors stepwise regressive analysis.MAIN OUTCOME MEASURES: ①Blood lead level and each factor scores of CBCL, ②correlation analysis between blood lead value and behavioral factor score.RESULTS: A total of 211 questionnaires were sent out, and 211 were retrieved with 211 effective questionnaires. The effective rate was 100%. ①Score on externalizing and behavioral disorder rate in the high blood lead exposure group (13.28±6.26,18.26%) was significantly higher than those in the low blood lead exposure group (9.98±5.46,7.29%)( t=4.067 7,χ2=5.470, P＜0.05). There was insignificant difference in score on internalizing and total score of CBCL between the low and high blood lead exposure groups. ②The behavioral disorder rate of different blood lead level had significance (χ2=13.695,P＜0.01). The behavioral disorder rate in blood lead ≥ 150 μg/L was obviously higher than that of the former 3groups after further pairwise comparison (χ2 were 4.727, 6.261, 5.168;4.503, 5.911, 4.928, P＜0.05), which revealed that the child behavioral disorder rate markedly increased when the blood lead was ≥ 150 μg/L.③Blood lead logarithm value had positive correlation with the scores on hyperactivity, aggression and defiance (r=0.316 4,0.282 8,0.188 6,P ＜0.05), and had no correlation with obesity, desintegration, truculence and sexual questionnaire (r=0.102 4,0.094 2,0.118 3,0.092 6,P ＞ 0.05). ④After the stepwise regression analysis, the scores on hyperactivity, aggression and defiance factors were included in the regression equation. The results suggested that the effect of lead on child externalizing behavior still remained, and kept statistical meaning after confounding factors, such as controlling family and society, etc.CONCLUSION: Low-level lead exposure has adverse effects on externalizing behavior in preschool children.
RESUMEN
BACKGROUND: Attachment reflects the early social experience of infant, which plays an important role in later child development. Although most of the attachment develops between infant and mother, some may occur between infant and care giver or others who have close relationship with it.OBJECTIVE: To analyze the infant-mother attachment patterns and the factors related to infant attachment.DESIGN: It was a sampling investigation.SETTING: Department of Maternal and Child Health, School of Public Health, Sun Yat-sen University.PARTICIPANTS: Totally 75 infants and their mother were selected randomly for this study in the Department of Child Health in Guangdong Maternal and Child Health Hospital from August to October 2002.METHODS: Strange situation test (SST) was performed by 6 researchers who were trained systematically. They watched the videos collectively and classified the patterns of infant attschment based on their performance. The internal consistency coefficient was 0.90. For those inconsistent assessments, the video should be reviewed and discussed to get an accordant conclusion. In addition, a self-designed maternal questionnaire was used to investigate the general condition of the infant and the familial information.MAIN OUTCOME MEASURES: ①Distribution of infant attachment patterns. ②Analysis of the risk factors related to infant attachment.RESULTS: All the 75 infants and their mother entered the statistical analysis. ①Distribution of the infant attachment patterns: In 75 infants, secure attachment was 65% and insecure attachment was 35%, among which,insecure-indifferent type was 18%, insecure-importunate type was 13%,and insecure-disorganized type was 4%. ②Analysis of the risk factors related to infant attachment Those infants with a younger age, a poor approachability (the response to strangers, new environment and objects), a closer relationship with caregiver and a more inconsistent education from the family members, are prone to develop insecure attachment.CONCLUSION: Secure attachment is dominant in infants. The security of attachment is related to the maturity and personality traits of the infants,the relationship between infant and caregiver and the educational approach for them. Key words Object attachment; Infant; Factor analysis, statistics