983 resultados para Dies (Metal-working)
Resumo:
OBJECTIVES: This study was designed to compare the long-term clinical outcome of coronary artery bypass grafting (CABG) with intracoronary stenting of patients with isolated proximal left anterior descending coronary artery. BACKGROUND: Although numerous trials have compared coronary angioplasty with bypass surgery, none assessed the clinical evaluation in the long term. METHODS: We evaluated the 10-year clinical outcome in the SIMA (Stent versus Internal Mammary Artery grafting) trial. Patients were randomly assigned to stent implantation versus CABG. RESULTS: Of 123 randomized patients, 59 underwent CABG and 62 received a stent (2 patients were excluded). Follow-up after 10 years was obtained for 98% of the randomized patients. Twenty-six patients (42%) in the percutaneous coronary intervention group and 10 patients (17%) in the CABG group reached an end point (p < 0.001). This difference was due to a higher need for additional revascularization. The incidences of death and myocardial infarction were identical at 10%. Progression of the disease requiring additional revascularization was rare (5%) and was similar for the 2 groups. Stent thrombosis occurred in 2 patients (3%). Angina functional class showed no significant differences between the 2 groups. CONCLUSIONS: Both stent implantation and CABG are safe and highly effective in relieving symptoms in patients with isolated, proximal left anterior descending coronary artery stenosis. Stenting with bare-metal stents is associated with a higher need for repeat interventions. The long-term prognosis for these patients is excellent with either mode of revascularization.
Resumo:
Actualment un típic embedded system (ex. telèfon mòbil) requereix alta qualitat per portar a terme tasques com codificar/descodificar a temps real; han de consumir poc energia per funcionar hores o dies utilitzant bateries lleugeres; han de ser el suficientment flexibles per integrar múltiples aplicacions i estàndards en un sol aparell; han de ser dissenyats i verificats en un període de temps curt tot i l’augment de la complexitat. Els dissenyadors lluiten contra aquestes adversitats, que demanen noves innovacions en arquitectures i metodologies de disseny. Coarse-grained reconfigurable architectures (CGRAs) estan emergent com a candidats potencials per superar totes aquestes dificultats. Diferents tipus d’arquitectures han estat presentades en els últims anys. L’alta granularitat redueix molt el retard, l’àrea, el consum i el temps de configuració comparant amb les FPGAs. D’altra banda, en comparació amb els tradicionals processadors coarse-grained programables, els alts recursos computacionals els permet d’assolir un alt nivell de paral•lelisme i eficiència. No obstant, els CGRAs existents no estant sent aplicats principalment per les grans dificultats en la programació per arquitectures complexes. ADRES és una nova CGRA dissenyada per I’Interuniversity Micro-Electronics Center (IMEC). Combina un processador very-long instruction word (VLIW) i un coarse-grained array per tenir dues opcions diferents en un mateix dispositiu físic. Entre els seus avantatges destaquen l’alta qualitat, poca redundància en les comunicacions i la facilitat de programació. Finalment ADRES és un patró enlloc d’una arquitectura concreta. Amb l’ajuda del compilador DRESC (Dynamically Reconfigurable Embedded System Compile), és possible trobar millors arquitectures o arquitectures específiques segons l’aplicació. Aquest treball presenta la implementació d’un codificador MPEG-4 per l’ADRES. Mostra l’evolució del codi per obtenir una bona implementació per una arquitectura donada. També es presenten les característiques principals d’ADRES i el seu compilador (DRESC). Els objectius són de reduir al màxim el nombre de cicles (temps) per implementar el codificador de MPEG-4 i veure les diferents dificultats de treballar en l’entorn ADRES. Els resultats mostren que els cícles es redueixen en un 67% comparant el codi inicial i final en el mode VLIW i un 84% comparant el codi inicial en VLIW i el final en mode CGA.
Resumo:
Cardiovascular magnetic resonance (CMR) has become an established imaging modality which provides often unique information on a wide range of cardiovascular diseases. The European Society of Cardiology (ESC) training curriculum reflects the emerging role of CMR by recommending that all trainees obtain a minimum level of training in CMR and by defining criteria for subspecialty training in CMR. 1 The wider use of CMR requires the definition of standards for data acquisition, reporting, and training in CMR across Europe. At the same time, training and accreditation in all cardiac imaging methods should be harmonized and integrated to promote the training of cardiac imaging specialists. The recommendations presented in this document are intended to inform the discussion about standards for accreditation and certification in CMR in Europe and the discussion on integrated imaging training. At present, the recommendations in this position statement are not to be interpreted as guidelines. Until such guidelines are available and nationally ratified, physicians will be able to train and practice CMR according to current national regulations.
Resumo:
This paper describes the application of the Soil and Water Assessment Tool (SWAT) model to the Maquoketa River watershed, located in northeast Iowa. The inputs to the model were obtained from the Environmental Protection Agency’s geographic information/database system called Better Assessment Science Integrating Point and Nonpoint Sources (BASINS). Climatic data from six weather stations located in and around the watershed, and measured streamflow data from a U.S. Geological Survey gage station at the watershed outlet were used in the sensitivity analysis of SWAT model parameters as well as its calibration and validation for watershed hydrology and streamflow. A sensitivity analysis was performed using an influence coefficient method to evaluate surface runoff and base flow variations in response to changes in model input hydrologic parameters. The curve number, evaporation compensation factor, and soil available water capacity were found to be the most sensitive parameters among eight selected parameters when applying SWAT to the Maquoketa River watershed. Model calibration, facilitated by the sensitivity analysis, was performed for the period 1988 through 1993, and validation was performed for 1982 through 1987. The model performance was evaluated by well-established statistical methods and was found to explain at least 86% and 69% of the variability in the measured stream flow data for the calibration and validation periods, respectively. This initial hydrologic modeling analysis will facilitate future applications of SWAT to the Maquoketa River watershed for various watershed analysis, including water quality.
Resumo:
Goals: Adjuvant chemotherapy decisions in breast cancer are increasing based on the pathologist's assessment of the proliferation fraction in the tumor. Yet, how good and how reproducible are we pathologists at providing reliable Ki-67 readings on breast carcinomas. Exactly how to count and in which areas to count within a tumor remains inadequately standardized. The Swiss Working Group of Gyneco- and Breast Pathologists has tried to appreciate this dilemma and to propose ways to obtain more reproducible results.Methods: In a first phase, 5 pathologists evaluated Ki67 counts in 10 breast cancers by exact counting (500 cells) and by eyeballing. Pathologists were free to select the region in which Ki67 was evaluated. In a second phase 16 pathologists evaluated Ki-67 counts in 3 breast cancers also by exact counting and eyeballing, but in predefined fields of interest. In both phases, Ki67 was assessed in centrally immunostained slides (ZH) and on slides immunostained in the 11 participating laboratories. In a third phase, these same 16 pathologists were once again asked to read the 3 cases from phase 2, plus three new cases, and this time exact guidelines were provided as to what exactly is considered a Ki-67 positive nucleus.Results: Discordance of Ki67 assessment was due to each of the following 4 factors: (i) pathologists' divergent definitions of what counts as a positive nucleus (ii) the mode of assessment (counting vs. eyeballing), (iii) immunostaining technique/protocol/antibody, and (iv) the selection of the area in which to count.Conclusion: Providing guidelines as to where to count (representative field in the tumor periphery and omitting hot spots) and what nuclei to count (even faintly immunostained nuclei count as positive) reduces the discordance rates of Ki67 readings between pathologists. Laboratory technique is only of minor importance (even over a large antibody dilution range), and counting nuclei does not improve accuracy, but rather aggravates deviations from the group mean values.Disclosure of Interest: None Declared
Resumo:
LEGISLATIVE STUDY – The 83rd General Assembly of the Iowa Legislature, in Senate File 2273, directed the Iowa Department of Transportation (DOT) to conduct a study of how to implement a uniform statewide system to allow for electronic transactions for the registration and titling of motor vehicles. PARTICIPANTS IN STUDY – As directed by Senate File 2273, the DOT formed a working group to conduct the study that included representatives from the Consumer Protection Division of the Office of the Attorney General, the Department of Public Safety, the Department of Revenue, the Iowa State County Treasurer’s Association, the Iowa Automobile Dealers Association, and the Iowa Independent Automobile Dealers Association. CONDUCT OF THE STUDY – The working group met eight times between June 17, 2010, and October 1, 2010. The group discussed the costs and benefits of electronic titling from the perspectives of new and used motor vehicle dealers, county treasurers, the DOT, lending institutions, consumers and consumer protection, and law enforcement. Security concerns, legislative implications, and implementation timelines were also considered. In the course of the meetings the group: 1. Reviewed the specific goals of S.F. 2273, and viewed a demonstration of Iowa’s current vehicle registration and titling system so participants that were not users of the system could gain an understanding of its current functionality and capabilities. 2. Reviewed the results of a survey of county treasurers conducted by the DOT to determine the extent to which county treasurers had processing backlogs and the extent to which county treasurers limited the number of dealer registration and titling transactions that they would process in a single day and while the dealer waited. Only eight reported placing a limit on the number of dealer transactions that would be processed while the dealer waited (with the number ranging from one to four), and only 11 reported a backlog in processing registration and titling transactions as of June 11, 2010, with most backlogs being reported in the range of one to three days. 3. Conducted conference calls with representatives of the American Association of Motor Vehicle Administrators (AAMVA) and representatives of three states -- Kansas, which has an electronic lien and titling (ELT) program, and Wisconsin and Florida, each of which have both an ELT program and an electronic registration and titling (ERT) program – to assess current and best practices for electronic transactions. In addition, the DOT (through AAMVA) submitted a survey to all U.S. jurisdictions to determine how, if at all, other states implemented electronic transactions for the registration and titling of motor vehicles. Twenty-eight states responded to the survey; of the 28 states that responded, only 13 allowed liens to be added or released electronically, and only five indicated allowing applications for registration and titling to be submitted electronically. DOT staff also heard a presentation from South Dakota on its ERT system at an AAMVA regional meeting. ELT information that emerged suggests a multi-vendor approach, in which vendors that meet state specifications for participation are authorized to interface with the state’s system to serve as a portal between lenders and the state system, will facilitate electronic lien releases and additions by offering lenders more choices and the opportunity to use the same vendor in multiple states. The ERT information that emerged indicates a multi-interface approach that offers an interface with existing dealer management software (DMS) systems and through a separate internet site will facilitate ERT by offering access that meets a variety of business needs and models. In both instances, information that emerged indicates that, in the long-term, adoption rates are positively affected by making participation above a certain minimum threshold mandatory. 4. To assess and compare functions or services that might be offered by or through a vendor, the group heard presentations from vendors that offer products or services that facilitate some aspect of ELT or ERT. 5. To assess the concerns, needs and interest of Iowa motor vehicle dealers, the group surveyed dealers to assess registration and titling difficulties experienced by dealers, the types of DMS systems (if any) used by dealers, and the dealers’ interest and preference in using an electronic interface to submit applications for registration and titling. Overall, 40% of the dealers that responded indicated interest and 57% indicated no interest, but interest was pronounced among new car dealers (75% were interested) and dealers with a high number of monthly transactions (85% of dealers averaging more than 50 sales per month were interested). The majority of dealers responding to the dealer survey ranked delays in processing and problems with daily limits on transaction as ―minor difficulty or ―no difficulty. RECOMMENDATIONS -- At the conclusion of the meetings, the working group discussed possible approaches for implementation of electronic transactions in Iowa and reached a consensus that a phased implementation of electronic titling that addressed first electronic lien and title transactions (ELT) and electronic fund transfers (EFT), and then electronic applications for registration and titling (ERT) is recommended. The recommendation of a phased implementation is based upon recognition that aspects of ELT and EFT are foundational to ERT, and that ELT and EFT solutions are more readily and easily attained than the ERT solution, which will take longer and be somewhat more difficult to develop and will require federal approval of an electronic odometer statement to fully implement. ELT – A multi-vendor approach is proposed for ELT. No direct costs to the state, counties, consumers, or dealers are anticipated under this approach. The vendor charges participating lenders user or transaction fees for the service, and it appears the lenders typically absorb those costs due to the savings offered by ELT. Existing staff can complete the programming necessary to interface the state system with vendors’ systems. The estimated time to implement ELT is six to nine months. Mandatory participation is not recommended initially, but should be considered after ELT has been implemented and a suitable number of vendors have enrolled to provide a fair assessment of participation rates and opportunities. EFT – A previous attempt to implement ELT and EFT was terminated due to concern that it would negatively impact county revenues by reducing interest income earned on state funds collected by the county and held until the monthly transfer to the state. To avoid that problem in this implementation, the EFT solution should remain revenue neutral to the counties, by allowing fees submitted by EFT to be immediately directed to the proper county account. Because ARTS was designed and has the capacity to accommodate EFT, a vendor is not needed to implement EFT. The estimated time to implement EFT is six to nine months. It is expected that EFT development will overlap ELT development. ERT – ERT itself must be developed in phases. It will not be possible to quickly implement a fully functioning, paperless ERT system, because federal law requires that transfer of title be accompanied by a written odometer statement unless approval for an alternate electronic statement is granted by the National Highway Traffic Safety Administration (NHTSA). It is expected that it will take as much as a year or more to obtain NHTSA approval, and that NHTSA approval will require design of a system that requires the seller to electronically confirm the seller’s identity, make the required disclosure to the buyer, and then transfer the disclosure to the buyer, who must also electronically confirm the buyer’s identity and electronically review and accept the disclosure to complete and submit the transaction. Given the time that it will take to develop and gain approval for this solution, initial ERT implementation will focus on completing and submitting applications and issuing registration applied for cards electronically, with the understanding that this process will still require submission of paper documents until an electronic odometer solution is developed. Because continued submission of paper documents undermines the efficiencies sought, ―full‖ ERT – that is, all documents necessary for registration and titling should be capable of approval and/or acceptance by all parties, and should be capable of submission without transmittal or delivery of duplicate paper documents .– should remain the ultimate goal. ERT is not recommended as a means to eliminate review and approval of registration and titling transactions by the county treasurers, or to place registration and titling approval in the hands of the dealers, as county treasurers perform an important role in deterring fraud and promoting accuracy by determining the genuineness and regularity of each application. Authorizing dealers to act as registration agents that approve registration and title applications, issue registration receipts, and maintain and deliver permanent metal license plates is not recommended. Although distribution of permanent plates by dealers is not recommended, it is recommended that dealers participating in ERT generate and print registration applied for cards electronically. Unlike the manually-issued cards currently in use, cards issued in this fashion may be queried by law enforcement and are less susceptible to misuse by customers and dealers. The estimated time to implement the electronic application and registration applied for cards is 12 to 18 months, to begin after ELT and EFT have been implemented. It is recommended that focus during this time be on facilitating transfers through motor vehicle dealers, with initial deployment focused on higher-volume dealers that use DMS systems. In the long term an internet option for access to ERT must also be developed and maintained to allow participation for lower-volume dealers that do not use a DMS system. This option will also lay the ground work for an ERT option for sales between private individuals. Mandatory participation in Iowa is not recommended initially. As with ELT, it is recommended that mandatory participation be considered after at least an initial phase of ERT has been implemented and a suitable number of dealers have enrolled to provide a fair assessment of participation rates and opportunities. The use of vendors to facilitate ERT is not initially proposed because 1) DOT IT support staff is capable of developing a system that will interact with DMS systems and will still have to develop a dealer and public interface regardless of whether a vendor acts as intermediary between the DMS systems, and 2) there is concern that the cost of the vendor-based system, which is funded by transaction-based payments from the dealer to the vendor, will be passed to the consumer in the form of additional documentation or conveyance fees. However, the DOT recommends flexibility on this point, as development and pilot of the system may indicate that a multi-vendor approach similar to that recommended for ELT may increase the adoption rate by larger dealers and may ultimately decrease the user management to be exercised by DOT staff. If vendors are used in the process, additional legislation or administrative rules may be needed to control the fees that may be passed to the consumer. No direct cost to the DOT or county treasurers is expected, as the DOT expects that it may complete necessary programming with existing staff. Use of vendors to facilitate ERT transactions by dealers using DMS systems would result in transaction fees that may ultimately be passed to consumers. LEGISLATION – As a result of the changes implemented in 2004 under Senate File 2070, the only changes to Iowa statutes proposed are to section 321.69 of the Iowa Code, ―Damage disclosure statement,and section 321.71, ―Odometer requirements.‖ In each instance, authority to execute these statements by electronic means would be clarified by authorizing language similar to that used in section 321.20, subsections ―2‖ and ―3,‖ which allows for electronic applications and directs the department to ―adopt rules on the method for providing signatures for applications made by electronic means.‖ In these sections, the authorizing language might read as follows: Notwithstanding contrary provisions of this section, the department may develop and implement a program to allow for any statement required by this section to be made electronically. The department shall adopt rules on the method for providing signatures for statements made by electronic means. Some changes to DOT administrative rules will be useful but only to enable changes to work processes that would be desirable in the long term. Examples of long term work processes that would be enabled by rule changes include allowing for signatures created through electronic means and electronic odometer certifications. The DOT rules, as currently written, do not hinder the ability to proceed with ELT, EFT, and ERT.
Resumo:
Purpose:To identify the gene causing rod-cone dystrophy/amelogenesis imperfecta Methods:Homozygosity mapping was performed using the Affymetrix 50K XbaI array in one family and candidate genes in the linked interval were sequenced with ABI Dye Terminator, vers. 1 in the index patient of 3 families. The identified mutations were screened in normal control individuals. Expression analyses were performed on RNA extracted from the brain, various parts of the eye and teeth; immunostaining was done on mouse eyes and jaw and knock-down experiments were carried out in zebrafish embroys. Results:Sequencing the coding regions of ancient conserved domain protein 4 (CNNM4), a metal ions transporter, revealed a 1-base pair duplication (p.L438fs) in family A, a p.R236Q mutation in family B and a p.L324P in family C. All these mutations were homozygous and involved very conserved amino acids in paralogs and orthologs. Immunostaining and RT-PCR confirmed that CNNM4 was strongly expressed in various parts of the eye and in the teeth. Morpholino experiments in zebrafish showed a loss of ganglion cells at 5 days post fertilization. Conclusions:The rod-cone dystrophy/amelogenesis imperfecta syndrome is caused by mutation in CNNM4 and is due to aberrant metal ion homeostasis.
Resumo:
We carry out a self-consistent analytical theory of unipolar current and noise properties of metal-semiconductor-metal structures made of highly resistive semiconductors in the presence of an applied bias of arbitrary strength. By including the effects of the diffusion current we succeed in studying the whole range of carrier injection conditions going from low level injection, where the structure behaves as a linear resistor, to high level injection, where the structure behaves as a space charge limited diode. We show that these structures display shot noise at the highest voltages. Remarkably the crossover from Nyquist noise to shot noise exhibits a complicated behavior with increasing current where an initial square root dependence (double thermal noise) is followed by a cubic power law.
Resumo:
In this work, we demonstrate that conductive atomic force microscopy (C-AFM) is a very powerful tool to investigate, at the nanoscale, metal-oxide-semiconductor structures with silicon nanocrystals (Si-nc) embedded in the gate oxide as memory devices. The high lateral resolution of this technique allows us to study extremely small areas ( ~ 300nm2) and, therefore, the electrical properties of a reduced number of Si-nc. C-AFM experiments have demonstrated that Si-nc enhance the gate oxide electrical conduction due to trap-assisted tunneling. On the other hand, Si-nc can act as trapping centers. The amount of charge stored in Si-nc has been estimated through the change induced in the barrier height measured from the I-V characteristics. The results show that only ~ 20% of the Si-nc are charged, demonstrating that the electrical behavior at the nanoscale is consistent with the macroscopic characterization.
Resumo:
The potential for application of silicon nitride-based light sources to general lighting is reported. The mechanism of current injection and transport in silicon nitride layers and silicon oxide tunnel layers is determined by electro-optical characterization of both bi- and tri-layers. It is shown that red luminescence is due to bipolar injection by direct tunneling, whereas Poole-Frenkel ionization is responsible for blue-green emission. The emission appears warm white to the eye, and the technology has potential for large-area lighting devices. A photometric study, including color rendering, color quality and luminous efficacy of radiation, measured under various AC excitation conditions, is given for a spectrum deemed promising for lighting. A correlated color temperature of 4800K was obtained using a 35% duty cycle of the AC excitation signal. Under these conditions, values for general color rendering index of 93 and luminous efficacy of radiation of 112 lm/W are demonstrated. This proof of concept demonstrates that mature silicon technology, which is extendable to lowcost, large-area lamps, can be used for general lighting purposes. Once the external quantum efficiency is improved to exceed 10%, this technique could be competitive with other energy-efficient solid-state lighting options. ©2011 Optical Society of America OCIS codes: (230.2090) Electro-optical devices; (150.2950) Illumination.
The effects of electron-hole separation on the photoconductivity of individual metal oxide nanowires
Resumo:
The responses of individual ZnO nanowires to UV light demonstrate that the persistent photoconductivity (PPC) state is directly related to the electron¿hole separation near the surface. Our results demonstrate that the electrical transport in these nanomaterials is influenced by the surface in two different ways. On the one hand, the effective mobility and the density of free carriers are determined by recombination mechanisms assisted by the oxidizing molecules in air. This phenomenon can also be blocked by surface passivation. On the other hand, the surface built-in potential separates the photogenerated electron¿hole pairs and accumulates holes at the surface. After illumination, the charge separation makes the electron¿hole recombination difficult and originates PPC. This effect is quickly reverted after increasing either the probing current (self-heating by Joule dissipation) or the oxygen content in air (favouring the surface recombination mechanisms). The model for PPC in individual nanowires presented here illustrates the intrinsic potential of metal oxide nanowires to develop optoelectronic devices or optochemical sensors with better and new performances.
Resumo:
A systematic method to improve the quality (Q) factor of RF integrated inductors is presented in this paper. The proposed method is based on the layout optimization to minimize the series resistance of the inductor coil, taking into account both ohmic losses, due to conduction currents, and magnetically induced losses, due to eddy currents. The technique is particularly useful when applied to inductors in which the fabrication process includes integration substrate removal. However, it is also applicable to inductors on low-loss substrates. The method optimizes the width of the metal strip for each turn of the inductor coil, leading to a variable strip-width layout. The optimization procedure has been successfully applied to the design of square spiral inductors in a silicon-based multichip-module technology, complemented with silicon micromachining postprocessing. The obtained experimental results corroborate the validity of the proposed method. A Q factor of about 17 have been obtained for a 35-nH inductor at 1.5 GHz, with Q values higher than 40 predicted for a 20-nH inductor working at 3.5 GHz. The latter is up to a 60% better than the best results for a single strip-width inductor working at the same frequency.
Resumo:
Phosphogysum (PG) or agricultural gypsum, a solid waste from the phosphate fertilizer industry, is used as soil amendment, especially on soils in the Cerrado region, in Brazil. This material may however contain natural radionuclides and metals which can be transferred to soils, plants and water sources. This paper presents and discusses the results of physical and chemical analyses that characterized samples of PG and compares them to the results found in two typical soils of the Cerrado, a clayey and sandy one. These analyses included: solid waste classification, evaluation of organic matter content and of P, K, Ca, Mg, and Al concentrations and of the mineralogical composition. Natural radionuclides and metal concentrations in PG and soil samples were also measured. Phosphogypsum was classified as Class II A - Not Dangerous, Not Inert, Not Corrosive and Not Reactive. The organic matter content in the soil samples was low and potential acidity high. In the mean, the specific 226Ra activity in the phosphogypsum samples (252 Bq kg-1) was below the maximum level recommended by USEPA, which is 370 Bq kg-1 for agricultural use. In addition, this study verified that natural radionuclides and metals concentrations in PG were lower than in the clayey Oxisol of Sete Lagoas, Minas Gerais, Brazil. These results indicated that the application of phosphogypsum as soil amendment in agriculture would not cause a significant impact on the environment.