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151.
P McDonald S E Bryan G J Hunt M Baldwin T G Parker 《Journal of radiological protection》2005,25(1):67-82
A survey of the contribution to external dose from gamma rays originating from intertidal sediments in the vicinity of the British Nuclear Group Sellafield site showed that the major anthropogenic contributions were due to (137)Cs and (60)Co. At some sites, traces of other anthropogenic radionuclides were detected, namely (106)Ru, (125)Sb, and (154)Eu. The proportions of fine grained material (<63 microm) were used to improve model predictions of dose contribution due to external exposure to gamma rays, using the CUMBRIA77/DOSE77 model. Model dose predictions were compared to those directly measured in the field. Using the new proportions of fine grained material (1-17.5%) in conjunction with field gamma-ray spectra, model predictions were improved considerably for most sites. Exceptions were at Drigg Barn Scar and Whitehaven Coal Sands sites, which had their own unique characteristics. The highest (60)Co activity concentrations in this study were detected at Drigg Barn Scar. These relatively high activity concentrations of (60)Co were due to the presence of (60)Co in mussels and barnacles, hence upsetting the fine sediment relationships used in previous dose calculations. Whitehaven Coal Sands was unusual in that it contained higher levels of radionuclides than would be expected in sandy sediment. The mineralogy of these sediments was the controlling factor on (137)Cs binding, rather than the proportion of fine grained material. By adjusting the effective fine grained sediment proportions for calculations involving (60)Co and (137)Cs at Drigg Barn Scar and Whitehaven Coal Sands respectively, the CUMBRIA77/DOSE77 model predictions could be improved upon significantly for these sites. This work highlights the influence of particle size and sediment composition on external dose rate calculations, as well as the potential for external dose contributions from biota. 相似文献
152.
Helstrom Amy Bryan Angela Hutchison Kent E. Riggs Paula D. Blechman Elaine A. 《Prevention science》2004,5(4):267-277
The prevalence and persistence of adolescent substance use and abuse is a national health issue, and substance use among adolescents is frequently comorbid with other psychiatric disorders. Most studies in this area utilize samples of middle or high school students or from inpatient settings. Less is known about substance use and psychiatric comorbidity among delinquent adolescents. The present study examined data from two cohorts of juvenile offenders collected over a 2-year period (n = 245, n = 299). Participants reported frequency of cigarette, alcohol, marijuana, and other substance use. Participants' parents completed a measure of behavior problems. Path analyses suggested that parental reports of externalizing problems were significantly related to self-reported substance use while parental reports of internalizing problems were not. Results also suggested that smoking and alcohol use act as mediators between externalizing problems and marijuana and other drug use. Although there were some mean differences by gender, the pattern of relationships amongst the variables did not differ by gender. Implications of the findings and future directions are discussed. 相似文献
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154.
Risk factors that may independently predict mortality and morbidity in patients with abdominal gunshot wounds have not been fully elucidated. We prospectively studied the effects of 12 potential risk factors on mortality and morbidity in 82 patients with abdominal gunshot wounds who required laparotomy. Univariate analysis of these factors revealed that shock on admission, presence of penetrating colon injury and number of intra-abdominal organs injured (NOI)>2 were associated with greater than threefold increased incidence of death (p<0.05). Penetrating abdominal trauma index (PATI) score>15 was associated with twentyfold increased incidence of death (P<0.0001). Multivariate analysis showed that only PATI (P=0.001), number of postoperative complications per patient (N(comp)) (P=0.023) and presence of shock on admission (P=0. 028) were independently significant in predicting mortality. PATI was the only risk factor that independently predicted the development of postoperative infectious complications and N(comp) (P<0.0001). The type of gun used was not a significant risk factor (P>0.05). The 15 (18.3%) non-survivors were significantly older than survivors (P=0.02), had longer operations (P=0.004) and their NOI, PATI and N(comp) were significantly higher (P<0.001). The uniformly prolonged injury to surgery time in all patients contributed to the high incidence of infectious complications (62.2%) and mortality. PATI score was the most important factor found to be independently associated with mortality and morbidity in our subset of patients with prolonged injury to surgery time and high rate of colon injury. 相似文献
155.
King BH 《Journal of autism and developmental disorders》2000,30(5):439-445
Aggression, self-injury, and mood disturbances in persons with autistic disorders, while not uncommon, do not constitute core features of autism. Moreover, these problems can occur for a variety of reasons, which need to be assessed in order to plan appropriate and frequently combined (behavioral-pharmacological) treatments. Drugs acting primarily in the dopaminergic, serotonergic, adrenergic, opioidergic, and glutamatergic systems all have been explored in the treatment of aggression and self-injury. While no single drug or class of medication has yet emerged as consistently effective, a number of drugs appear promising. Advances in the assessment of aggressive behaviors, the identification of predictors of drug response, and additional controlled clinical drug trials specifically aimed at these target behaviors are essential in improving the approach to these problematic behaviors in the context of autistic disorder. 相似文献
156.
157.
Fass U Panickar K Personett D Bryan D Williams K Gonzales J Sugaya K McKinney M 《Neuroreport》2000,11(5):931-936
Many neuronal nitric oxide synthase (nNOS)-expressing brain neurons, including some cholinergic populations, are resistant to disease or to certain forms of excitotoxicity. Vulnerability to NO excess of forebrain (medial septal/diagonal band; MS-ACh) and brainstem (pedunculopontine/laterodorsal tegmental nuclei; BS-ACh) cholinergic neurons was compared in E16-E18 primary rat brain cultures. MS-ACh cells were approximately 300-fold more sensitive to the NO donor S-nitro-N-acetyl-D,L-penicillamine (SNAP) than were BS-ACh cells. Most (69%) MS-ACh cells contained nuclear DNA fragments by 2 h after addition of SNAP, while only 21% BS-ACh cells were TUNEL-positive after NO excess. Depletion of glutathione content did not potentiate the effect of SNAP on MS-ACh cells, but sensitized BS-ACh cells to the NO donor. Caffeic acid, a putative NF-kappa B inhibitor, enhanced the toxicity of SNAP to cholinergic neurons in both preparations. Our experiments show that cholinergic neurons in mixed primary cultures from different brain regions possess biochemical differences with respect to their vulnerability to NO excess. 相似文献
158.
OBJECTIVE To investigate the expression of Coxsackie and Adenovirus receptor (CAR) in renal-cell carcinoma and the relationship of the CAR to the biological behavior of the carcinomas.METHODS The immunohistochemical SP method was used to detect the expression of Coxsaekie and Adenovirus receptor in 48 cases of renalcell carcinoma and in 12 cases of normal renal tissue 2 cm away from the tumor tissue.RESULTS The positive rates of CAR were 100% in 12 cases of para-tumcr normal renal tissue and 35.4% in 48 cases of renal-cell carcinoma respectively. The difference of CAR expression between them was significant (P<0.05). The grades of the tumor were as follows: 22 in Grade Ⅰ, 17in Grade Ⅱ and 9 in Grade Ⅲ with the CAR positive rate being 54.5%,23.5% and 11.1%, respectively. There was a negative correlation between CAR expression and tumor grading (P<0.05). In addition, the number of the cases in stages Ⅰ to ⅣV were 19, 13, 11 and 5 respectively, with the respective positive rates being 57.9%, 30.8%, 18.2% and 0.0%, i.e. there also was a negative relationship between CAR expression and the stage (P<0.05).CONCLUSION CAR expression is down-regulated in renal-cell carcinoma compared with normal tissue. The level of CAR may be a sensitive predictor of differentiation, invasion and metastasis. Loss of CAR expression correlates with the invasive phenotype in our analysis of renal-cell carcinoma. 相似文献
159.
160.