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131.
Purpose. This paper compares unsteady-state and steady-state methods for estimating dermal absorption or analyzing dermal absorption data. The unsteady-state method accounts for the larger absorption rates during short exposure times as well as the hydrophilic barrier which the viable epidermis presents to lipophilic chemicals.
Methods. Example calculations for dermal absorption from aqueous solutions are presented for five environmentally relevant chemicals with molecular weights between 50 and 410 and log10Kow between 0.91 and 6.8: chloromethane, chloroform, chlordane, 2,3,7,8-TCDD, and dibenz(a,h)anthracene. Also, the new method is used to evaluate experimental procedures and data analyses of in vivo and in vitro permeation measurements.
Results. In the five example cases, we show that the steady-state approach significantly underestimated the dermal absorption. Also, calculating permeability values from cumulative absorption data measured for exposure periods less than 18 times the stratum corneum lag time will overestimate the actual permeability.
Conclusions. In general, steady-state predictions of dermal absorption will underestimate dermal absorption predictions which consider unsteady-state conditions. Permeability values calculated from data sets which include unsteady-state data will be incorrect. Strategies for analyzing in vitro diffusion cell experiments and confirming steady state are described. 相似文献
132.
D. A. Basketter E. W. Scholes M. Cumberbatch C. D. Evans I. Kimber 《Contact dermatitis》1992,27(4):209-213
The guinea pig maximization test (GPMT) has proven to be a valuable tool for the identification of the skin sensitization potential of chemicals. The method identifies a hazard which can lead in the EC to compulsory labelling of that chemical. In the present study, data on sulphanilic acid derived from the GPMT has been compared with results from a second guinea pig assay (the cumulative contact enhancement test) and the murine local lymph node assay, both of which require only topical application of chemical. Except for the GPMT, no test identified any sensitizing activity associated with exposure to sulphanilic acid. These latter results are consistent with the experience gained from substantial human exposure in an occupational setting and from which no cases of allergic contact dermatitis to sulphanilic acid have arisen over a 20-year period. In consequence, it is questioned which test protocol in practice has given the more accurate identification of sensitization hazard relevant to man. 相似文献
133.
Most clinicians agree that psychological factors are important considerations in the evaluation and treatment of headache patients. There has been a lack of systematic research, however, that has examined the relationship between these variables. Attention to such factors may become a greater concern as the frequency of a patient's headaches increases, there is increased disability secondary to headaches, and/or there is an inadequate response to usually effective treatment. In addition, there is no consensus as to the proper method to assess psychopathology in headache patients. 相似文献
134.
目的:建立胃癌个体危险度判定及人群筛检的数量化模型。方法:在人群为基础的胃癌危险因素病例对照研究的基础上筛选出有统计学意义变化,应用概率论、模糊数学等原理和方法对胃癌危险因素和保护因素数量化,建立用于个体胃癌危险度测量和人群筛检的数量化评价方法(数学模型)。采用两种不同的加权系数计算方法,分别确定该数量化方法的判别阈值为0.20和0.17,对63例胃癌患者和693名正常人进行实际判别。结果:灵敏度和特异度均分别达到69%和63%左右,加权系数计算方法不同并不影响实际判别效果。结论:建立的胃癌个体危险度及人群筛检的数量化模型灵敏度和特异度尚理想;方法简便、易行、经济,有利于获得满意的受检率;可用于个体和群体(社区)的胃癌危险度测定。 相似文献
135.
目的 探讨计算机体层成像多平面重建(CTMPR)在评价椎间融合中的作用,寻找定量评价椎间融合的新方法.方法 13例行腰椎间融合的患者术后1周、3个月、6个月行CTMPR,行椎间融合器(Cage)内植骨CT值定量测量.结果 术后1周Cage内植骨CT值为(619.52±26.97)Hu,术后3个月为(628.69±42.60)Hu,术后6个月为(657.77±37.43)Hu.术后1周与术后3个月相比无显著性差异,与术后6个月相比有显著性差异.结论 CT值的测量在椎间融合的判断中具有高准确性. 相似文献
136.
Heukrodt Carol; Powazek Morris; Brown Warren S.; Kennelly Denise; Imbus Charles; Robinson Herb; Schantz Stacy 《Journal of pediatric psychology》1988,13(2):223-236
The long-term effects of disease and treatment on electrophysiologicalmeasures of neurocognitive function were studied in childrenwho had survived acute lymphoblastic leukemia (ALL) for at least4 years and were currently in remission. We report here changesin cognitive processing time as shown by the latency of theP3 wave of the auditory event-related EEG potential (ERP). P3latency was significantly prolonged in long-term ALL surivors,as well as in patients successfully trreated for solid tumors(ST)outside the CNS who received similar chemotherapy but did notreceive prophylactic treatment to the CNS. P3 latencies werestrongly correlated with measures of school performance andIQ in these individuals. The similarity in P3 latency betweenthe ALL and ST groups suggests that the treatments used on thesepateints produce changes in electrophysiological responses thatare associated with mild, but significant, cognitive deficits. 相似文献
137.
初产妇30例,用亲水性聚氯酯泡沫宫颈扩张棒(简称“扩张棒”)作人工剥膜与破膜加催产素引产前扩张宫颈,同时以条件类同初产妇30例进行对照。扩张棒组置棒前宫颈成熟度评分为2.93±0.91,对照组为3.7±0.88,两组无显著差异:扩张后宫颈评分为6.13±1.22,与扩张前有显著差异(P<0.05)。扩张棒组引产成功率为92.6%,而对照组为64.3%,差异非常显著(P<0.01),同时能缩短产程。本组用扩张棒组引产的30例,无一例发生产时、产后感染。 相似文献
138.
Two methods of assessing candidates for coloured overlays were compared with the aim of determining which method had the most practical utility. A total of 58 adults were assessed as potential candidates for coloured overlays, using two methods; a questionnaire, which identified self-reported previous symptoms, and a measure of perceptual distortions immediately prior to testing. Participants were classified as normal, Meares-Irlen sensitive, and borderline sensitive. Reading speed was measured with and without coloured overlays, using the Wilkins Rate of Reading Test and the change in speed was calculated. Participants classified as normal did not show any significant benefit from reading with an overlay. In contrast, a significant reading advantage was found for the borderline and Meares-Irlen participants. Current symptom rating was found to be a significant predictor of the change in reading speed, however the previous symptom rating was not found to be a reliable predictor. These data indicate that the assessment of perceptual distortions immediately prior to measuring colour preference and reading speed is the most meaningful method of assessing pattern glare and determining the utility of coloured overlays. 相似文献
139.
Effect of Population Aging on the International Organ Donation Rates and the Effectiveness of the Donation Process 总被引:2,自引:2,他引:0
N. Cuende J. I. Cuende J. Fajardo J. Huet M. Alonso 《American journal of transplantation》2007,7(6):1526-1535
This study analyzed the effect of population aging on organ donation for transplants in 43 countries and on the effectiveness of the donation process by comparing the results between Spain and the United States. The percentage of the population aged 65 or over accounted for 33% of the difference in the donation rates between the countries and for 91% of the variation in the rates after age adjustment. However, the level of aging of the Spanish (16.5%) and American (12.3%) populations failed to account for the percentages of deceased donors 65 or over (28% vs. 10%), due to the different age-specific donation rates, much higher in Spain above 50 years. These differences lead to a higher effectiveness of the process in the United States (3.1 transplanted organs per donor vs. 2.5 in Spain), though at lower rates of transplant per million population (73 vs. 87). We conclude that older populations have a greater donation potential as donation rates are strongly associated with population aging. It should therefore be mandatory to adjust donation rates for age before making comparisons. Additionally, effectiveness decreases with older donors, so age should be considered when establishing standards relating to organ donation and effectiveness of the process. 相似文献
140.
B. Cyrulnik M. Delage M.-N. Blein S. Bourcet A. Dupays 《Annales médico-psychologiques》2007,165(3):154-161
The newborn are subject to the bond between infants and their caregivers. The newborn receives the imprint of a style of attachment of which the function involves “proximity-maintenance” and “separation-protest”. The “secure-base” uses the attachment as a base from which the newly born is able to explore his environment. The continuity between childhood and adult relationships changes when romantic love and sexual appetite appear. A new kind of attachment with the love partner must develop and it has to support both attachment and sexuality. The youngster produces the same secure, avoiding, ambivalent or confused attachment as when he was an infant but, as opposed to that with his family, when the young person is attached to his partner he doesn't want to leave. In order to assess the link between the attachment with caregivers and the attachment with the first love, we proposed a questionnaire, a kind of “Love quiz”. First, the representation of attachment with their parents was assessed by four columns of ten questions. Each question referred to a style of attachment, for instance at the end of the interview, the column asking questions about avoidance displayed seven answers, whereas the secure column showed only three answers and the confused only one. Later, the same questionnaire was submitted in order to describe the new attachment with the first love. Results showed that the commitment to romantic love was similar to those observed among infants. But, after a while, the scores obtained in each column evolved: Fourteen out of twenty symptomatic adolescents improved their secure score; three remained in the same style of attachment and three others felt their first love as a traumatism. Out of eighteen no-symptomatic adolescents, fourteen were secure. Only four were insecure. After the first love, the rate of insecure adolescents increased to eight; four others were traumatised. The first love probably sets up a sensitive period in which biology, emotion and culture converge to enable us to be imprinted by a partner. An affect regulation with romantic partners is negotiated like a transaction between two styles of attachment. What is surprising is that the population of insecure adolescents benefited more from romantic love than the secure population by increasing their score in the attachment style. Adult relationships can be understood in terms of attachment. The first attachment is acquired during early interactions, and when the beginnings of life are difficult the first love gives them a second chance. 相似文献