934 resultados para Single-case design
Resumo:
The case of a 16-year-old patient with atrioventricular tachycardia caused by a single left anterolateral accessory pathway is reported. When the patient underwent radiofrequency ablation, a lesion on the mitral annulus lateral wall produced changes in the retrograde atrial activation pattern determined by that pathway; changes ranged from a delay in depolarization of the annulus posterior portions to full left atrium counterclockwise activation. Such phenomena were probably caused by a block in the isthmus between the annulus and the lower left pulmonary vein ostium. This case illustrates the importance of the mitral-pulmonary isthmus in the process of left atrium activation, an alert to changes induced by its unintentional block during accessory pathway ablation.
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This thesis presents the research and development of sustainable design guidelines for the furniture and wood products industry, suitable for sustainably enhancing design, manufacturing and associated activities. This sustainable guideline is based on secondary research conducted on subject areas such as ‘eco’ design, ‘green’ branding and ‘green’ consumerism, as well as an examination of existing certifications and sustainable tools techniques and methodologies, national and international drivers for sustainable development and an overview of sustainability in the Irish furniture manufacturing context. The guideline was further developed through primary research. This consisted of a focus group attended by leading Irish designers, manufacturers and academics in the area of furniture and wood products. This group explored the question of ‘green branding’ saturation in the market and the viability of investing in sustainability just yet. Participants stated that they felt the market for ‘green’ products is evolving very slowly and that there is no metric or legal framework present to audit whether or not companies are producing products that really embody sustainability. All the participants believed that developing and introducing a new certification process to incorporate a sustainable design process was a viable and necessary solution to protecting Irish furniture and wood manufacturers going forward. For the purposes of the case study, the author investigated a ‘sustainable’ design process for Team woodcraft, Ltd., through the design and development of a ‘sustainable’ children’s furniture range. The case study followed a typical design and development process; detailing customer design specifications, concept development and refinement and cumulating in final prototype, as well as associated engineering drawings. Based on this primary and secondary research, seven fundamental core principles for this sustainable guideline have been identified by the author. The author then used these core principles to expand into guidelines for the basis of proposed new Irish sustainable design guidelines for the furniture and wood products industry, the concept of which the author has named ‘Green Dot’. The author suggests that the ‘Green Dot’ brand or logo could be used to market an umbrella network of Irish furniture designers and manufactures who implement the recommended sustainable techniques.
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Abdominal Aortic Aneurysms (AAA) haemorhaging is a life-threatening disease. An aneurysm is a permanent swelling of an artery due to a weakness in its wall. Current surgical repair involves opening the chest or abdomen, gaining temporary vascular control of the aorta and suturing a prosthetic graft to the healthy aorta within the aneurysm itself The outcome of this surgical approach is not perfect, and the quality of life after this repair is impaired by postoperative pain, sexual dysfunction, and a lengthy hospital stay resulting in high health costs. All these negative effects are related to the large incision and extensive tissue dissection. Endovascular grafting is an alternative to the standard surgical method. This treatment is a less invasive method of treating aortic aneurysms. It involves a surgical exposure of the common femoral arteries where the stent graft can be inserted through by an over-the-wire technique. All manipulations are controlled from a remote place by the use of a catheter and this technique avoids the need to directly expose the diseased artery through a large incision or an extensive dissection. The proposed design method outlined in this project is to develop the endovascular approach. The main aim is to design an unitary bifurcated stent graft (1 e- bifurcated graft as a single component) to treat these Abdominal Aortic Aneurysms. This includes the delivery system and deployment mechanism necessary to first accurately position the stent graft across the aneurysm sac and also across the iliac bifurcation, and secondly fix the stent graft in position by using expandable metal stents. Thus, excluding the aneurysm from the circulation and therefore preventing rupture. Miniaturisation is a critical aspect of this design, as the smaller the crimped stent graft the easier to guide through the vascular system to the desired location. Biocompatibility is an important aspect. The preferred materials for this prosthesis are to use Shape Memory Alloys for the stent and a multifilament fabric for the graft. A taper design is applied for the geometry as this gives a favourable flow characteristic and reduced wave reflections. Adequate testing of the stent graft to prove its durability and the ease of the method of deployment is a prerequisite. A bench test facility has being designed and build to replicate the cardiovascular system and the disease in question aortic aneurysms at the iliac bifurcation. The testing here shows the feasibility of the proposed delivery system and the durability of the stent graft across the aneurysm sac. Finally, these endovascular treatments offer the economic advantage of short hospital stays or even treatment as an outpatient, as well as elimination of the need for postoperative intensive care The risk of developing an aneurysm increases with age, that is one of the mam reasons to look for less invasive ways of treating aneurysms. Consequently, there is enormous pressure to develop and use these devices rapidly.
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Nowadays a huge attention of the academia and research teams is attracted to the potential of the usage of the 60 GHz frequency band in the wireless communications. The use of the 60GHz frequency band offers great possibilities for wide variety of applications that are yet to be implemented. These applications also imply huge implementation challenges. Such example is building a high data rate transceiver which at the same time would have very low power consumption. In this paper we present a prototype of Single Carrier -SC transceiver system, illustrating a brief overview of the baseband design, emphasizing the most important decisions that need to be done. A brief overview of the possible approaches when implementing the equalizer, as the most complex module in the SC transceiver, is also presented. The main focus of this paper is to suggest a parallel architecture for the receiver in a Single Carrier communication system. This would provide higher data rates that the communication system canachieve, for a price of higher power consumption. The suggested architecture of such receiver is illustrated in this paper,giving the results of its implementation in comparison with its corresponding serial implementation.
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We use statistical techniques to quantify the effects of school attainment on individual wages, participation rates and employment probabilities in Spain, and to measure the contribution of education to labour productivity at the regional level. These estimates are then combined with data on private and public expenditure on education and with information on taxes and social benefits to construct measures of the private and social returns to schooling, to explore the effects of public policies on private incentives to invest in human capital, and to analyse the long-term effects of schooling on public finances. The results are used, together with estimates of the returns to alternative assets, to draw some tentative conclusions regarding the adequacy of the aggregate investment patterns observed in the regions of Spain, and to identify changes in the design of national and EU cohesion and growth policies that may help enhance their effectiveness.
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The metropolitan spatial structure displays various patterns, sometimes monocentricity and sometimes multicentricity, which seems much more complicated than the exponential density function used in classic works such as Clark (1961), Muth (1969) or Mills (1973) among others, can effectively represent. It seems that a more flexible density function,such as cubic spline function (Anderson (1982), Zheng (1991), etc.) to describe the density-accessibility relationship is needed. Also, accessibility, the fundamental determinant of density variations, is only partly captured by the inclusion of distance to the city centre as an explanatory variable. Steen (1986) has proposed to correct that miss-especification by including an additional gradient for distance to the nearest transportation axis. In identifying the determinants of urban spatial structure in the context of inter-urban systems, some of the variables proposed by Muth (1969), Mills (1973) and Alperovich (1983) such as city age or population, make no sense in the case of a single urban system. All three criticism to the exponential density function and its determinants apply for the Barcelona Metropolitan Region, a polycentric conurbation structured on well defined transportation axes.
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In this paper we analyze the determination of "key" sectors in the final energy consumption. We approach this issue from an input-output perspective and we design a methodology based on the elasticities of the demands of final energy consumption. As an exercise, we apply the proposed methodology to the Spanish economy. The analysis allows us to indicate the greater or lesser relevance of the different sectors in the consumption of final energy, pointing out which sectors deserve greater attention in the Spanish case and showing the implications for energy policy.
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Purpose - This paper focuses on analyzing the effect that public reforms have on the efficiency of state-owned enterprises in regulated environments. Design/methodology/approach - The research is focused in the postal sector where public and private companies must obey a legal framework related to provide a universal service. The analysis is carried out using a panel of 7 European postal operators for the period 1997-2003. The activity analyzed was the letter mail division; we take as key variable the unit cost of a letter and use a translog cost function where as independent variables we include traffic levels, labor cost per employee, quality and availability of the service as well as the type of ownership (public or private). Additionally, in a second stage the geographical differences among countries are considered. Findings - Results indicate that postal operators that experienced organizational changes without being privatized, such as the Spanish and Greek operators, do not have higher unit costs than privatized postal operators like the one of Germany and the Netherlands. Moreover, we find that in all cases the operator of Ireland appear to be the most efficient. In this case restructuring process has been carried out giving an important leadership role to workers. This suggests us that labor culture could be a key variable to study when analyzing reform processes in public enterprises. Originality/value - Our findings show that in a regulated environment like in the postal sector, public and private companies can obtain similar efficiency levels in term of unit costs.
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Un reto al ejecutar las aplicaciones en un cluster es lograr mejorar las prestaciones utilizando los recursos de manera eficiente, y este reto es mayor al utilizar un ambiente distribuido. Teniendo en cuenta este reto, se proponen un conjunto de reglas para realizar el cómputo en cada uno de los nodos, basado en el análisis de cómputo y comunicaciones de las aplicaciones, se analiza un esquema de mapping de celdas y un método para planificar el orden de ejecución, tomando en consideración la ejecución por prioridad, donde las celdas de fronteras tienen una mayor prioridad con respecto a las celdas internas. En la experimentación se muestra el solapamiento del computo interno con las comunicaciones de las celdas fronteras, obteniendo resultados donde el Speedup aumenta y los niveles de eficiencia se mantienen por encima de un 85%, finalmente se obtiene ganancias de los tiempos de ejecución, concluyendo que si se puede diseñar un esquemas de solapamiento que permita que la ejecución de las aplicaciones SPMD en un cluster se hagan de forma eficiente.
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INTRODUCTION: EORTC trial 22991 was designed to evaluate the addition of concomitant and adjuvant short-term hormonal treatments to curative radiotherapy in terms of disease-free survival for patients with intermediate risk localized prostate cancer. In order to assess the compliance to the 3D conformal radiotherapy protocol guidelines, all participating centres were requested to participate in a dummy run procedure. An individual case review was performed for the largest recruiting centres as well. MATERIALS AND METHODS: CT-data of an eligible prostate cancer patient were sent to 30 centres including a description of the clinical case. The investigator was requested to delineate the volumes of interest and to perform treatment planning according to the protocol. Thereafter, the investigators of the 12 most actively recruiting centres were requested to provide data on five randomly selected patients for an individual case review. RESULTS: Volume delineation varied significantly between investigators. Dose constraints for organs at risk (rectum, bladder, hips) were difficult to meet. In the individual case review, no major protocol deviations were observed, but a number of dose reporting problems were documented for centres using IMRT. CONCLUSIONS: Overall, results of this quality assurance program were satisfactory. The efficacy of the combination of a dummy run procedure with an individual case review is confirmed in this study, as none of the evaluated patient files harboured a major protocol deviation. Quality assurance remains a very important tool in radiotherapy to increase the reliability of the trial results. Special attention should be given when designing quality assurance programs for more complex irradiation techniques.
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CD8 T cells play a key role in mediating protective immunity against selected pathogens after vaccination. Understanding the mechanism of this protection is dependent upon definition of the heterogeneity and complexity of cellular immune responses generated by different vaccines. Here, we identify previously unrecognized subsets of CD8 T cells based upon analysis of gene-expression patterns within single cells and show that they are differentially induced by different vaccines. Three prime-boost vector combinations encoding HIV Env stimulated antigen-specific CD8 T-cell populations of similar magnitude, phenotype, and functionality. Remarkably, however, analysis of single-cell gene-expression profiles enabled discrimination of a majority of central memory (CM) and effector memory (EM) CD8 T cells elicited by the three vaccines. Subsets of T cells could be defined based on their expression of Eomes, Cxcr3, and Ccr7, or Klrk1, Klrg1, and Ccr5 in CM and EM cells, respectively. Of CM cells elicited by DNA prime-recombinant adenoviral (rAd) boost vectors, 67% were Eomes(-) Ccr7(+) Cxcr3(-), in contrast to only 7% and 2% stimulated by rAd5-rAd5 or rAd-LCMV, respectively. Of EM cells elicited by DNA-rAd, 74% were Klrk1(-) Klrg1(-)Ccr5(-) compared with only 26% and 20% for rAd5-rAd5 or rAd5-LCMV. Definition by single-cell gene profiling of specific CM and EM CD8 T-cell subsets that are differentially induced by different gene-based vaccines will facilitate the design and evaluation of vaccines, as well as enable our understanding of mechanisms of protective immunity.
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Introduction/objectives: Multipatient use of a single-patient CBSD occurred inan outpatient clinic during 4 to 16 months before itsnotification. We looked for transmission of blood-bornepathogens among exposed patients.Methods: Exposed patients underwent serology testing for HBV,HCV and HIV. Patients with isolated anti-HBc receivedone dose of hepatitis B vaccine to look for a memoryimmune response. Possible transmissions were investigatedby mapping visits and sequencing of the viral genomeif needed.Results: Of 280 exposed patients, 9 had died without suspicionof blood-borne infection, 3 could not be tested, and 5declined investigations. Among the 263 (93%) testedpatients, 218 (83%) had negative results. We confirmeda known history of HCV infection in 6 patients (1 coinfectedby HIV), and also identified resolved HBVinfection in 37 patients, of whom 18 were alreadyknown. 2 patients were found to have a previouslyunknown HCV infection. According to the time elapsedfrom the closest previous visit of a HCV-infected potentialsource patient, we could rule out nosocomial transmissionin one case (14 weeks) but not in the other (1day). In the latter, however, transmission was deemedvery unlikely by 2 reference centers based on thesequences of the E1 and HVR1 regions of the virus.Conclusion: We did not identify any transmission of blood-bornepathogens in 263 patients exposed to a single-patientCBSD, despite the presence of potential source cases.Change of needle and disinfection of the device betweenpatients may have contributed to this outcome.Although we cannot exclude transmission of HBV, previousacquisition in endemic countries is a more likelyexplanation in this multi-national population.
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STUDY OBJECTIVE: Prior research has identified five common genetic variants associated with narcolepsy with cataplexy in Caucasian patients. To replicate and/or extend these findings, we have tested HLA-DQB1, the previously identified 5 variants, and 10 other potential variants in a large European sample of narcolepsy with cataplexy subjects. DESIGN: Retrospective case-control study. SETTING: A recent study showed that over 76% of significant genome-wide association variants lie within DNase I hypersensitive sites (DHSs). From our previous GWAS, we identified 30 single nucleotide polymorphisms (SNPs) with P < 10(-4) mapping to DHSs. Ten SNPs tagging these sites, HLADQB1, and all previously reported SNPs significantly associated with narcolepsy were tested for replication. PATIENTS AND PARTICIPANTS: For GWAS, 1,261 narcolepsy patients and 1,422 HLA-DQB1*06:02-matched controls were included. For HLA study, 1,218 patients and 3,541 controls were included. MEASUREMENTS AND RESULTS: None of the top variants within DHSs were replicated. Out of the five previously reported SNPs, only rs2858884 within the HLA region (P < 2x10(-9)) and rs1154155 within the TRA locus (P < 2x10(-8)) replicated. DQB1 typing confirmed that DQB1*06:02 confers an extraordinary risk (odds ratio 251). Four protective alleles (DQB1*06:03, odds ratio 0.17, DQB1*05:01, odds ratio 0.56, DQB1*06:09 odds ratio 0.21, DQB1*02 odds ratio 0.76) were also identified. CONCLUSION: An overwhelming portion of genetic risk for narcolepsy with cataplexy is found at DQB1 locus. Since DQB1*06:02 positive subjects are at 251-fold increase in risk for narcolepsy, and all recent cases of narcolepsy after H1N1 vaccination are positive for this allele, DQB1 genotyping may be relevant to public health policy.
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Objectives: Skin can be partially regenerated after full thickness defects by collagen matrices, In this study, we identified the main limitations of induced regeneration aiming to improve the design of dermal matrices. Methods: Single mice received a 1 cm2, full thickness skin wound on the dorsum, which were grafted with collagen-GAG matrices or left ungrafted. The healing modulation induced by the collagen-GAG matrices was compared to spontaneous healing and to custom designed, bioactive, poly-N-Acetyl- Glucosamine (NAG) matrices. Wound staging was based on macroscopic, histological and immunhistochemical analysis on days 3, 7, 10 and 21 post wounding. Results: Cell density was higher in spontaneously granulating wounds compared to grafted wounds. While grafted wounds exhibited increased levels of cell proliferation on days 7 and 10, vascularity was dramatically reduced. NAG scaffolds accelerated both angiogenesis and wound re-epithelialization. Conclusions: Since slow integration and revascularization severely limit the engraftment of clinically used dermal scaffolds, the design of dermal matrices using bioactive materials represent the next step in skin regeneration.
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We demonstrate that RecA protein can mediate annealing of complementary DNA strands in vitro by at least two different mechanisms. The first annealing mechanism predominates under conditions where RecA protein causes coaggregation of single-stranded DNA (ssDNA) molecules and where RecA-free ssDNA stretches are present on both reaction partners. Under these conditions annealing can take place between locally concentrated protein-free complementary sequences. Other DNA aggregating agents like histone H1 or ethanol stimulate annealing by the same mechanism. The second mechanism of RecA-mediated annealing of complementary DNA strands is best manifested when preformed saturated RecA-ssDNA complexes interact with protein-free ssDNA. In this case, annealing can occur between the ssDNA strand resident in the complex and the ssDNA strand that interacts with the preformed RecA-ssDNA complex. Here, the action of RecA protein reflects its specific recombination promoting mechanism. This mechanism enables DNA molecules resident in the presynaptic RecA-DNA complexes to be exposed for hydrogen bond formation with DNA molecules contacting the presynaptic RecA-DNA filament.