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121.
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
122.
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
123.
124.
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
125.
126.
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
127.
128.
Vaccination Decreases the Infectious Viral Load of Delta Variant SARS-CoV-2 in Asymptomatic Patients
Jessica A. Plante Rafael R. G. Machado Brooke M. Mitchell Divya P. Shinde Jordyn Walker Dionna Scharton Allan McConnell Nehad Saada Jianying Liu Bilal Khan Rafael K. Campos Bryan A. Johnson Vineet D. Menachery Corri B. Levine Ping Ren Susan L. F. McLellan Kenneth S. Plante Scott C. Weaver 《Viruses》2022,14(9)
The Delta variant of SARS-CoV-2 has caused many breakthrough infections in fully vaccinated individuals. While vaccine status did not generally impact the number of viral RNA genome copies in nasopharyngeal swabs of breakthrough patients, as measured by Ct values, it has been previously found to decrease the infectious viral load in symptomatic patients. We quantified the viral RNA, infectious virus, and anti-spike IgA in nasopharyngeal swabs collected from individuals asymptomatically infected with the Delta variant of SARS-CoV-2. Vaccination decreased the infectious viral load, but not the amount of viral RNA. Furthermore, vaccinees with asymptomatic infections had significantly higher levels of anti-spike IgA in their nasal secretions compared to unvaccinated individuals with asymptomatic infections. Thus, vaccination may decrease the transmission risk of Delta, and perhaps other variants, despite not affecting the amount of viral RNA measured in nasopharyngeal swabs. 相似文献
129.
Xiaoning Guo Xiaohui Wang Sui Shen Bryan Oronsky Tony R Reid Meaghan Stirn Scott Caroen Franck Brinkhaus Nacer A Abrouk Liandai Yang Lianzong Wu Zhongwen Yu 《American journal of cancer research》2022,12(9):4448
RRx-001, a CD47 antagonist via its inhibition of MYC and the γ-subtype of the peroxisome proliferator-activated receptor (PPAR) has been associated to date with minimal toxicity. The aim of this post-hoc analysis was to evaluate the toxicity and efficacy of RRx-001 in Asian patients since RRx-001, in the context of multiple Phase 3 studies, will be administered in China and Chinese territories as well as potentially throughout the rest of Asia. Patients received 4 mg of RRx-001 in three different antitumor clinical trials with chemotherapy and/or radiation and a retrospective subset efficacy and toxicity analysis was conducted for patients with Asian ancestry in comparison to patients with other ethnic backgrounds. The toxicity and efficacy data from these studies were similar between Asians and the rest of the treated patients. While the sample sizes are too small to draw definitive conclusions, at a dose of 4 mg, when RRx-001 is combined with chemotherapy, no apparent differences in terms of safety and efficacy are observed in cancer patients with Asian ancestry. 相似文献