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31.
A multiplex polymerase chain reaction (PCR) assay was designed to simplify detection of Escherichia coli O157:H7 and to identify the H serogroup and the type of Shiga toxin produced by this bacterium. Primers for a plasmid-encoded hemolysin gene (hly933), and chromosomal flagella (fliCh7; flagellar structural gene of H7 serogroup), Shiga toxins (stx1, stx2), and attaching and effacing (eaeA) genes were used in a multiplex PCR for coamplification of the corresponding DNA sequences from enterohemorrhagic E. coli (EHEC) O157:H7. Enrichment cultures of ground beef, blue cheese, mussels, alfalfa sprouts, and bovine feces, artificially inoculated with various levels of E. coli O157:H7 strain 933, were subjected to a simple DNA extraction step prior to the PCR, and the resulting amplification products were analyzed by agarose gel electrophoresis. Sensitivity of the assay was < or = 1 CFU/g of food or bovine feces (initial inoculum level), and results could be obtained within 24 h. Similar detection levels were obtained with ground beef samples that underwent enrichment culturing immediately after inoculation and samples that were frozen or refrigerated prior to enrichment. The multiplex PCR facilitates detection of E. coli O157:H7 and can reduce the time required for confirmation of isolates by up to 3 to 4 days.  相似文献   
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Passive radiometry is a health-safe alternative to other imaging techniques conceived to be used on human beings for security screening or medical imaging applications. In this work we address a study on the feasibility of W-band passive radiometers in nano-scale CMOS technology for imaging applications. In particular, this study takes into account some of the most relevant aspects regarding the system-on-a-chip implementation, from system to circuit and technology limitations, with emphasis on the impact of the non-idealities of the detector on the overall system performances. Excluding the hardware differences between the investigated receiver architectures and their substantial implications, especially in case of array systems, the investigation shows how there is no a clear evidence to identify a priori the best performance receiver architecture, but it depends on the circuits, as well as operating frequency and technology.  相似文献   
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In this paper the output tracking control problem for a class of non‐linear time delay systems with some unknown constant parameters is addressed. Such a problem is solved in the case that the non‐linear time‐delay system has full delay relative degree and stable internal dynamics. It is supposed moreover that the output and its time derivatives until n?1, where n is the length of the state vector (euclidean part), do not depend explicitly on the unknown parameters. This work is the first step towards the application of the methodologies of adaptive control for non‐linear delayless systems, based on tools of differential geometry, to non‐linear time‐delay systems too. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
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Attempts to assist psychologists involved in policy discussions regarding the economics of mental health care by summarizing important sources of information on the characteristics and trends of psychological service providers and the cost of such services. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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superconducting thin films by Mo75Re25 single-target magnetron sputtering at various temperatures on sapphire substrates were prepared. Sharp superconductive transitions andT c values above 10 K were achieved, and the deposited films showed a good metallic behavior. According to structural analyses (EDS and X-rays), all the samples have the same stoichiometry as the target and, even at low deposition temperatures, they exhibit theA15 phase. From measured residual resistivities and superconducting critical temperatures the theoretical BCS surface resistances were estimated and compared to those o Mo60Re40 films, presented in a previous work. Both these alloys, in fact, being characterized by low surface resistances and high critical fields, are good candidates as coating films in r.f. cavities.  相似文献   
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This discussion about advanced cardiac life support (ACLS) reflects disappointment with the over 50% of out-of-hospital cardiopulmonary resuscitation (CPR) attempts that fail to achieve restoration of spontaneous circulation (ROSC). Hospital discharge rates are equally poor for in-hospital CPR attempts outside special care units. Early bystander CPR and early defibrillation (manual, semi-automatic or automatic) are the most effective methods for achieving ROSC from ventricular fibrillation (VF). Automated external defibrillation (AED), which is effective in the hands of first responders in the out-of-hospital setting, should also be used and evaluated in hospitals, inside and outside of special care units. The first countershock is most important. Biphasic waveforms seem to have advantages over monophasic ones. Tracheal intubation has obvious efficacy when the airway is threatened. Scientific documentation of specific types, doses, and timing of drug treatments (epinephrine, bicarbonate, lidocaine, bretylium) are weak. Clinical trials have failed so far to document anything statistically but a breakthrough effect. Interactions between catecholamines and buffers need further exploration. A major cause of unsuccessful attempts at ROSC is the underlying disease, which present ACLS guidelines do not consider adequately. Early thrombolysis and early coronary revascularization procedures should also be considered for selected victims of sudden cardiac death. Emergency cardiopulmonary bypass (CPB) could be a breakthrough measure, but cannot be initiated rapidly enough in the field due to technical limitations. Open-chest CPR by ambulance physicians deserves further trials. In searches for causes of VF, neurocardiology gives clues for new directions. Fibrillation and defibrillation thresholds are influenced by the peripheral sympathetic and parasympathetic nervous systems and impulses from the frontal cerebral cortex. CPR for cardiac arrest of the mother in advanced pregnancy requires modifications and outcome data. Until more recognizable critical factors for ROSC are identified, titrated sequencing of ACLS measures, based on physiologic rationale and sound judgement, rather than rigid standards, gives the best chance for achieving survival with good cerebral function.  相似文献   
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There is growing recognition that race and socioeconomic variables in health research demand greater attention. The investigators compared racial differences in health definition, health value, and health-promoting behavior of 62 pairs (N = 124) of Black and White college women matched on age, body mass index, and socioeconomic status. Both groups of women had similar definitions of health, valued health to the same extent, and reported similar levels of self-actualization, health responsibility, exercise, and stress management. Black women, relative to White women, practiced fewer nutrition behaviors and had less interpersonal support. Interventions to reduce health risk associated with nutrition practices of Black women are warranted and further research is needed to explore the influence of the social structure of educational institutions on interpersonal relationships and other health behaviors. When socioeconomic status is taken into consideration, Black and White college women demonstrated more commonalities in health behavior than differences.  相似文献   
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