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The objective of this study was to estimate the availability of large weight capacity computed tomography (CT) and magnetic resonance imaging (MRI) equipment in US hospitals with emergency departments (EDs) and to evaluate animal facilities as alternate sources of imaging. We conducted a telephone survey of radiology technicians from a random sample of all the US hospitals with EDs (n = 262) and all 136 primary hospitals of academic EDs, 145 zoos, and 28 veterinary schools. We measured the prevalence of large weight capacity (>450 lb) CT and MRI, stratified by hospital characteristics. Response rates were 94-100% across samples. Nationally, 10% (95% confidence interval, 7-15) of hospitals with EDs had large weight capacity CT and 8% (95% confidence interval, 5-13) had large weight capacity MRI. In academic hospitals, access to large capacity equipment was better for CT (28%), but similar for MRI (10%) (P < 0.001 and 0.51, respectively). Few rural (5%) and critical-access hospitals (3%) had large capacity CT. In addition, 34% of trauma centers, 23% of stroke centers, and 21% of bariatric surgery centers of excellence had large capacity CT. Only two zoos (1%) had CT scanners; both would not image human patients. Among veterinary schools, 16 (57%) had large weight capacity CT equipment, but only 4 (14%) would consider imaging human patients. Further, 23 (82%) veterinary schools reported policies that specifically prohibited imaging humans. For patients who weigh >450 lb, access to emergent CT and MRI is limited, even at academic and bariatric surgery centers. Animal facilities are not a viable alternative for diagnostic imaging of human patients.  相似文献   
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An ab initio model for gene prediction in prokaryotic genomes is proposed based on physicochemical characteristics of codons calculated from molecular dynamics (MD) simulations. The model requires a specification of three calculated quantities for each codon: the double-helical trinucleotide base pairing energy, the base pair stacking energy, and an index of the propensity of a codon for protein-nucleic acid interactions. The base pairing and stacking energies for each codon are obtained from recently reported MD simulations on all unique tetranucleotide steps, and the third parameter is assigned based on the conjugate rule previously proposed to account for the wobble hypothesis with respect to degeneracies in the genetic code. The third interaction propensity parameter values correlate well with ab initio MD calculated solvation energies and flexibility of codon sequences as well as codon usage in genes and amino acid composition frequencies in ∼175,000 protein sequences in the Swissprot database. Assignment of these three parameters for each codon enables the calculation of the magnitude and orientation of a cumulative three-dimensional vector for a DNA sequence of any length in each of the six genomic reading frames. Analysis of 372 genomes comprising ∼350,000 genes shows that the orientations of the gene and nongene vectors are well differentiated and make a clear distinction feasible between genic and nongenic sequences at a level equivalent to or better than currently available knowledge-based models trained on the basis of empirical data, presenting a strong support for the possibility of a unique and useful physicochemical characterization of DNA sequences from codons to genomes.  相似文献   
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This work investigates the potential of metabolic stimulators, firstly to enhance the production of beta-carotene, and later use of inhibitors of lycopene cyclase so as to accumulate lycopene in the fermentation medium. Various non-ionic surfactants, natural oils, stimulators such as amino-acids, tricarboxylic acid cycle (TCA) intermediates, vitamin A and antibiotics were investigated for improved production of beta-carotene using the zygomycete fungus Blakeslea trispora. Span 20 at 0.2% increased the beta-carotene production from 139 mg/l to 318 mg/l. Examination of the mycelial morphology of the B. trispora with span 20 showed a shorter mycelial length, which allowed a well-dispersed growth of B. trispora. Supplementation of the medium with 1000 ppm vitamin A acetate gave highest concentration of beta-carotene (830+/-6 mg/l). Several chemical inhibitors such as imidazole, pyridine, triethylamine, piperidine, and nicotinic acid were then evaluated to block the biosynthesis at lycopene. Piperidine at 500 ppm gave a 7.76-fold improvement, and produced high titers of lycopene (775+/-5 mg/l) in a medium supplemented with vitamin A acetate.  相似文献   
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S Kacew  R L Singhal 《Life sciences》1973,13(10):1363-1371
Administration of an acute oral dose of p,p′-DDT (600 mg/kg), α-chlordane (200 mg/kg), heptachlor (200 mg/kg) and endrin (50 mg/kg) produced a significant rise in the concentration of serum glucose and urea and a lowering of hepatic glycogen. In addition, treatment with either of these insecticides significantly increased the activities of hepatic and renal pyruvate carboxylase, phosphoenolpyruvate carboxykinase, fructose 1,6-diphosphatase and glucose 6-phosphatase, the four enzymes which play a key, rate-limiting role in the process of gluconeogenesis. Treatment with p,p′-DDT, α-chlordane, heptachlor or endrin proved equally effective in elevating the levels of endogenous cyclic AMP and augmenting the activity of basal- and fluoride-stimulated forms of adenyl cyclase in both tissues. Whereas renal phosphodiesterase was decreased slightly by p,p′-DDT, the activity of this cyclic AMP-degrading enzyme remained unaltered following the administration of other pesticides. Our data indicate that the pesticide-induced alterations in carbohydrate metabolism of liver and kidney may be associated with an enhanced ability of these organs to synthesize cyclic AMP.  相似文献   
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Gum arabic is used as an encapsulating agent because of its film-forming ability. However, India has to import gum arabic for its domestic requirement. Oxidised starch has been reported as a substitute for gum arabic but no data are reported on the exact conditions of oxidation of starch or the analytical indicators for determining the suitability of the product for such a purpose. This work reports on the effect of process conditions for oxidation of corn and waxy amaranth starch with film-forming ability as the major criterion. The process was followed using the analytical indicators of oxidation such as carboxyl content, chlorine consumption and ferricyanide number.  相似文献   
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