193 research outputs found
Collection and analysis of multispectral magnetic resonance imaging data using a clinical imaging system
As most radiologists would attest, the accuracy of pathology diagnosis is greatly increased by acquiring more information about the tissue in question. An innovative data acquisition technique has been developed that will do just that - gather more information about the tissues being studied. As each tissue type is composed of a unique arrangement of chemical components, each tissue exhibits a characteristic nuclear magnetic resonance (NMR) frequency spectrum. Unfortunately, current clinical magnetic resonance imaging (MRI) systems integrate the characteristic spectra of the tissue within a voxel to create a single signal for the voxel, thus throwing away what could be invaluable information. In an effort to regain the typically discarded information, a spatial-spatial-spectral imaging technique has been developed and demonstrated using a clinical MRI system. The technique, which was originally developed and demonstrated by Lauterbur on a NMR system, involves acquiring projections through the spatial-spectral plane of the spatial-spatial-spectral volume and reconstructing that plane through use of a back-projection procedure. This technique is made possible on clinical MRI systems through the advent of variable bandwidth imaging - a technological advance that allows for a variation in the sampling bandwidth used in the acquisition steps of MRI. Combined with specific variations of the frequency-encoding gradient, specific bandwidth values can be used with existing pulse sequences to acquire projections through the spatial-spectral plane at very particular angles. The technique has been demonstrated on a 1.5T, whole-body, clinical imaging system (Signa, GE Medical Systems, Milwaukee, WI) using chemical shift phantoms as well as in vivo tissue. In addition, the accuracy of the technique has been analyzed via point spread function (PSF) estimation and classification accuracy techniques. The impacts on these analysis metrics due to variations in acquisition and processing parameters have also been investigated
Infrared symbolic scene comparator
Infrared image analysis has become a very popular subject of study. Situations as recent as the Gulf War have proved the advantages, and therefore the need, of having not only the proper imaging equipment but the training and expertise to use that equipment. To date, there are few tools that analysts can use to educate themselves and the operators of the state-of-the-art imaging equipment. There are even fewer tools that provide the flexibility to control nearly every aspect of infrared imaging phenomena. Several pre-existing and a few new remote sensing sub-systems have been combined to create an extremely user-friendly infrared imaging analysis package that can be used to educate people about infrared imaging phenomena or as a direct analysis tool to assist analysts in distinguishing between infrared phenomena in actual imagery
Peptoids and methods for treating alzheimer\u27s disease
Peptoids capable of inhibiting or reversing amyloid .beta. (A.beta.) fibril or plaque production are described. The peptoids form a helical structure with three monomers per helical turn and have at least two monomers with a side-chain having an arylalkyl group having the same chirality positioned such that the side-chains are on the same side of the peptoid. Methods of using the peptoids to inhibit or reverse aggregation of A.beta of treating subjects with Alzheimer\u27s disease (AD) or slowing the progression of AD are also provided
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Misbehavior, Suspensions, and Security Measures in High School: Racial/Ethnic and Gender Differences
This study used merged data from three national surveys to address questions about security measures in American high schools, suspension rates, and student misbehavior. First, the study identified the characteristics of schools that implemented the most extreme security measures and those with the highest levels of discipline. Second, the study used data on individual students to examine misbehavior and race and gender disparities in suspensions not attributable to misbehavior. The main findings were: (1) In-school suspensions serve a ‘gateway’ function with regard to out-of-school suspensions. They may provide a time and place to address behavior problems before they escalate or disproportionate out-of-school suspensions before they occur; (2) Out-of-school suspensions were more frequent among schools in higher-crime neighborhoods. Thus students suspended may be relegated to an environment not conducive to positive educational or social outcomes; (3) African-American students and Hispanic/Latino students were suspended at higher rates than were non-Hispanic whites, differences in most cases not attributable to different levels of misbehavior; (4) Overall, males were more likely to be suspended than were females, an effect above and beyond that explained by differences in behavior. There was little or no difference in the suspension rates of black males and females, however; (5) High degrees of school security were associated with increased suspension rates and increased black – white disparities in total suspensions. At the same time, most black students were enrolled in schools with high degrees of security; (6) Black males were suspended at higher and higher rates as school size increased.
All of these have implications for school policy and practice. These are discussed in the paper together with limitations of the investigation
Peptoids and methods for attenuating inflammatory response
Disclosed herein are peptoids and methods for attenuating inflammatory responses, and more particularly RAGE-associated inflammatory responses
Peptoids and methods for treating Alzheimer\u27s disease
Provided herein are peptoids capable of inhibiting or reversing amyloid .beta. (A.beta.) fibril or plaque production. The peptoids form a helical structure with three monomers per helical turn and have at least four monomers with a side-chain having an arylalkyl or aryl group. The peptoid may be achiral. Also provided are methods of using the peptoids to inhibit or reverse aggregation of A.beta. and methods of treating subjects with Alzheimer\u27s disease (AD) or slowing the progression of AD
Non-natural protein mimetics for the treatment of Alzheimer\u27s disease
Alzheimer\u27s disease (AD) is a slow degenerative disease that causes memory loss and eventually leads to death. AD is caused by the aggregation of the amyloid-beta protein, found on the outside of brain cells; once the amyloid-beta protein begins to aggregate it forms plaques on the extracellular part of the neural cells. To date there is no AD medication commercially available that breaks up the amyloid-beta aggregates. Current research has found that certain molecules bind to the amyloid-beta protein and prevent aggregation. The purpose of this research project is to engineer a peptoid-based molecule to stop the aggregation of the amyloid-beta protein. Peptoids have been found to form strong helices, have high bioactivity, and are easy and cost-effective to synthesize. Three peptoids with different chemistries at only the 6th side chain have been designed; the first peptoid is neutral, the second peptoid is positive, and the third peptoid is negative. The binding ability of the peptoids with the amyloid-beta protein will be tested at the University of South Carolina in the laboratory of Dr. Melissa Moss. Currently the peptoids have been synthesized and are in the process of purification and characterization. The peptoids binding ability with the amyloid-beta protein will provide important information regarding their use for the therapeutic treatment of AD
Hollow fibers for artificial lung applications
Artificial lungs are in use, but difficult issues remain in the field of membrane development related to fouling issues. Currently there are external artificial lungs circulating blood outside the body, taking out the carbon dioxide, and inserting oxygenated blood back into the body. An example of this type of machine is the ExtraCorporeal Membrane Oxygenation (ECMO) machine currently used in hospitals. The ECMO takes over the functions for both the lungs and the heart but is only available for short term use by patients with respiratory failure due to infections (1). The fibers in the machine develop fouling due to the fibers’ small surface areas coupled with their long term exposure to proteins in the blood. These factors continuously decrease the gas transfer abilities of the fibers until the machine is no longer effective at exchanging gases with the blood. The goal of this research is to create a lung that can function within the body until an actual lung becomes available using hollow fiber membranes with proteins attached to prevent fouling. A fouling study was performed on 17.8% polysulfone hollow fiber membranes with polydopamine and peptoid attached. Unmodified, polydopamine modified, and polydopamine and peptoid modified fibers were placed in a diffusion chamber with Bovine Serum Albumin (BSA) flowing on the outside of the fibers and oxygen flowing on the inside. Evapoporometry was run on the fibers to determine the pore size distribution of the fibers before and after the run. The evapoporometry of the fibers shows that the pores for the fibers after 48 hours in the chamber are smaller overall with a few larger pores from oxygen flowrate being too high, tearing the pores. There were also fewer pores overall in the fibers after the run; therefore, the fibers are fouling in the diffusion chamber. The oxygen concentration of the BSA was also measured while the BSA was run outside of the fibers in the chamber. The fibers were considered to be completely fouled when no more oxygen was able to diffuse into the BSA. The fouling was shown to take longer to occur in the protein coated fibers than in the unmodified fibers.
Reference:
(1) Downs, M. (2014, October 18). Artificial Lung Closer to Clinical Trial. Retrieved from WebMD: http://www.webmd.com/lung/features/ar tificial-lung-closer-to-clinical-trial
Estimating impacts on safety caused by the introduction of electronic medical records in primary care
Context Primary care is a highly complex environment in which multiple safety problems have been identified. Each primary care practice can be viewed as a complex adaptive system with its own unique characteristics. The introduction of an electronic medical record (EMR) into such a system represents a significant perturbation that can have multiple unpredictable effects. From a safety standpoint this can mean reduction in some vulnerabilities and increase in others, as well as the introduction of new vulnerabilities that did not exist under the old system.
Objective To estimate the impacts of a new EMR on various aspects of practice function using a Failure Modes and Effects Analysis (FMEA) approach based on the concept of hazard adapted from safety engineering.
Setting/participants Academic rural primary care practice with 32 staff.
Design At baseline, a survey instrument (Perceived Hazard Questionnaire) was used to elicit staff (physicians, nurses and administrative) perceptions of frequency and severity of multiple different primary care errors in 12 different domains in the practice. For each error, a Hazard score was calculated based on the product of frequency and severity. The Hazard scores thus derived were used to prioritise the safety problems within the practice. One year later, after partial implementation of an EMR, the survey was repeated.
Main outcome measures Comparison is made between priorities identified by physicians, nursing and administrative staff before and after EMR implementation.
Results At baseline, a high concordance between priorities identified by physicians, nursing and administrative staff was recorded. This concordance halved after partial implementation of the EMR. The staff perceived decreased hazard in nurse– physician and physician–chart interactions but hazard increased in the already high-hazard domains of physician–patient interaction in the assessment stage and nurse–chart interactions, apart from three other domains.
Conclusions This FMEA-like approach identified changes in practice hazards apparently related to EMR implementation. This in turn can help in targeting pre-existing and new vulnerabilities in primary care practices
Using standardized patient encounters to teach longitudinal continuity of care in a family medicine clerkship
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