205 research outputs found
TARGETED POLYMERIC BIOMATERIALS FOR THE PREVENTION OF POST SURGICAL ADHESIONS
Despite recent advances in surgical technique and the development of numerous therapeutic agents, the formation post surgical adhesions (PSA) continues to cause complications for many patients. In this research, we have employed a rational system to develop a novel treatment to address this clinical need. Based on an understanding of the biochemical events that lead to PSA formation, a series of targeted polymeric biomaterials was designed to interrupt the fibrin gel matrix propagation and suppress PSA formation.
Using group transfer polymerization, a series of well controlled block copolymers of polyacrylic acid and poly(ethylene glycol-methacrylate) based materials was synthesized. Subsequent functionalization with the pentapeptide Cys-Arg-Glu-Lys-Ala (CREKA) was employed to target the materials to fibrin as a marker of pro-adhesive sites. While preliminary testing of the untargeted materials verified their ability to suppress non-specific protein adsorption to model surfaces, numerous in vitro tests were conducted to study the ability to inhibit fibrin gel propagation. The ability to inhibit both the rate and quantity of fibrinogen deposition to a fibrin coated surface has been demonstrated. In addition, the rate of fibrin gel propagation and the degree of cellular attachment can modulated.
Taking advantage of the systematic variation in structure facilitated by the robust synthetic methodology employed, statistical analysis was used to elucidate the structureproperty relationships governing the performance of these materials. The most important factors that lead to enhanced performance in in vitro tests are the length of PEG chain and number of peptide units conjugated to the polymer: increasing PEG chain length and increasing the number of peptides conjugated to the polymer both improve performance in all tests. The synthetic methods that have been developed, in conjunction with the experimental results, will be used to direct future studies, including cytotoxicity and animal studies
Compounds and Methods for Reducing the Occurrence of Post-Surgical Adhesions
Compounds and methods for reducing the occurrence of a post-surgical adhesion are provided. The compounds can include acrylic acid groups and ethylene glycol groups, and can be directed to an area of damaged tissue by the incorporation of a fibrin targeting peptide. The compounds can further include a brush-like portion, capable of creating a steric barrier between a damaged tissue or organ and adjacent tissues or organs, and a targeting portion, capable of directing the compounds to a damaged tissue or organ. Methods of detecting damaged tissue and kits are also provided
Can physical joint simulators be used to anticipate clinical wear problems of new joint replacement implants prior to market release?
Medley, J. B. (2016). Can physical joint simulators be used to anticipate clinical wear problems of new joint replacement implants prior to market release? Proceedings of the Institution of Mechanical Engineers. Part H, Journal of Engineering in Medicine, 230(5), 347–358. Copyright © 2016. Sage Publications. Reprinted by permission of SAGE Publications. https://doi.org/10.1177/0954411916643902One of the most important mandates of physical joint simulators is to provide test results that allow the implant manufacturer to anticipate and perhaps avoid clinical wear problems with their new products. This is best done before market release. This study gives four steps to follow in conducting such wear simulator testing. Two major examples involving hip wear simulators are discussed in which attempts had been made to predict clinical wear performance prior to market release. The second one, involving the DePuy ASR implant systems, is chosen for more extensive treatment by making it an illustrative example to explore whether wear simulator testing can anticipate clinical wear problems. It is concluded that hip wear simulator testing did provide data in the academic literature that indicated some risk of clinical wear problems prior to market release of the ASR implant systems. This supports the idea that physical joint simulators have an important role in the pre-market testing of new joint replacement implants
Education for democracy
The authors general thesis is that if we are serious about the need of planning for better world after the war the first thing to start thinking about is education. This is done by developing two definitions of two familiar words and then stating four general propositions. The first word is democracy which the author defines as a system of society in which a large majority of the citizens are not only qualified in mind and body to play a significant part in the common business of community, but actually have opportunities to do so. Secondly, education is defined as the process by means of which boys and girls do or do not become citizens so qualified. The four propositions are : 1. Any system of society is no better and no worse than the system of education which it fosters, 2. We are resolved that our system of society will after the war become a ‘democratic’ one, 3. The possibility of a ‘democratic’ society is dependant on equal opportunity and adequate facilities for learning cooperation, 4. a ‘democratic’ society is impossible which does not insist upon a broad system of education both of mind and body. [Author abstract, ed
Incidence and severity of respiratory syncytial virus pneumonia in rural Kenyan children identified through hospital surveillance
Background.Although necessary for developing a rationale for vaccination, the burden of severe respiratory syncytial virus (RSV) disease in children in resource‐poor settings remains poorly defined.
Methods.We conducted prospective surveillance of severe and very severe pneumonia in children aged <5 years admitted from 2002 through 2007 to Kilifi district hospital in coastal Kenya. Nasal specimens were screened for RSV antigen by immunofluorescence. Incidence rates were estimated for the well‐defined population.
Results.Of 25,149 hospital admissions, 7359 patients (29%) had severe or very severe pneumonia, of whom 6026 (82%) were enrolled. RSV prevalence was 15% (20% among infants) and 27% during epidemics (32% among infants). The proportion of case patients aged 3 months was 65%, and the proportion aged 6 months was 43%. Average annual hospitalization rates were 293 hospitalizations per 100,000 children aged <5 years (95% confidence interval, 271–371 hospitalizations per 100,000 children aged <5 years) and 1107 hospitalizations per 100,000 infants (95% confidence interval, 1012–1211 hospitalizations per 100,000 infants). Hospital admission rates were double in the region close to the hospital. Few patients with RSV infection had life‐threatening clinical features or concurrent serious illnesses, and the associated mortality was 2.2%.
Conclusions.In this low‐income setting, rates of hospital admission with RSV‐associated pneumonia are substantial; they are comparable to estimates from the United States but considerably underestimate the burden in the full community. An effective vaccine for children aged >2 months (outside the age group of poor responders) could prevent a large portion of RSV disease. Severity data suggest that the justification for RSV vaccination will be based on the prevention of morbidity, not mortality
Cognitive code-division links with blind primary-system identification
Abstract—We consider the problem of cognitive code-division channelization (simultaneous power and code-channel allocation) for secondary transmission links co-existing with an unknown primary code-division multiple-access (CDMA) system. We first develop a blind primary-user identification scheme to detect the binary code sequences (signatures) utilized by primary users. To create a secondary link we propose two alternative procedures –one of moderate and one of low computational complexity – that optimize the secondary transmitting power and binary codechannel assignment in accordance with the detected primary code channels to avoid “harmful ” interference. At the same time, the optimization procedures guarantee that the signalto-interference-plus-noise ratio (SINR) at the output of the maximum SINR linear secondary receiver is no less than a certain threshold to meet secondary transmission quality of service (QoS) requirements. The extension of the channelization problem to multiple secondary links is also investigated. Simulation studies presented herein illustrate the theoretical developments. Index Terms—Blind user identification, code-channel allocation, code-division multiple-access, cognitive radio, dynamic spectrum access, power allocation, signal-to-interference-plusnoise ratio. I
Evidence gathering in support of sustainable Scottish inshore fisheries: work package (6) final report: integrating stock management considerations with market opportunities in the Scottish inshore fisheries sector – a pilot study
In June 2014, Hambrey Consulting successfully responded to a call for tenders for research to undertake a pilot assessment of the potential economic and associated benefits of establishing minimum market landing size (MMLS) in excess of minimum legal landing size (MLS) for shellfish; and to evaluate if such an intervention could be undertaken at a regional level.
The project was originally conceived as including 3 case studies, but the scope of the research led us to focus mainly on the trawl and creel fishery for Nephrops prosecuted by the fleet based in Skye and SW Ross. The basic framework for the assessment approach was to: Develop an economic profile of the case study area and its fishing fleet; Review and synthesise existing data on size profile of the catch, the factors that affect size, including costs associated with individual (vessel) actions or strategies to increase the size profile of the catch; Analyse market and market trends, and the prices for different sizes of product; Develop economic models of representative fishing enterprises, taking account of the relationships between costs and returns and the size profile of the catch; Use plausible scenarios to explore likely short term economic consequences of any changes in MMLS; Use yield and utility per recruit analysis to explore possible yield benefits associated with increased MMLS.Publisher PD
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