Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 38
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Cochrane Database Syst Rev ; 7: CD004125, 2017 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-28715610

RESUMO

BACKGROUND: Drugs can prevent postoperative nausea and vomiting, but their relative efficacies and side effects have not been compared within one systematic review. OBJECTIVES: The objective of this review was to assess the prevention of postoperative nausea and vomiting by drugs and the development of any side effects. SEARCH METHODS: We searched The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 2, 2004), MEDLINE (January 1966 to May 2004), EMBASE (January 1985 to May 2004), CINAHL (1982 to May 2004), AMED (1985 to May 2004), SIGLE (to May 2004), ISI WOS (to May 2004), LILAC (to May 2004) and INGENTA bibliographies. SELECTION CRITERIA: We included randomized controlled trials that compared a drug with placebo or another drug, or compared doses or timing of administration, that reported postoperative nausea or vomiting as an outcome. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trial quality and extracted outcome data. MAIN RESULTS: We included 737 studies involving 103,237 people. Compared to placebo, eight drugs prevented postoperative nausea and vomiting: droperidol, metoclopramide, ondansetron, tropisetron, dolasetron, dexamethasone, cyclizine and granisetron. Publication bias makes evidence for differences among these drugs unreliable. The relative risks (RR) versus placebo varied between 0.60 and 0.80, depending upon the drug and outcome. Evidence for side effects was sparse: droperidol was sedative (RR 1.32) and headache was more common after ondansetron (RR 1.16). AUTHORS' CONCLUSIONS: Either nausea or vomiting is reported to affect, at most, 80 out of 100 people after surgery. If all 100 of these people are given one of the listed drugs, about 28 would benefit and 72 would not. Nausea and vomiting are usually less common and, therefore, drugs are less useful. For 100 people, of whom 30 would vomit or feel sick after surgery if given placebo, 10 people would benefit from a drug and 90 would not. Between one to five patients out of every 100 people may experience a mild side effect, such as sedation or headache, when given an antiemetic drug. Collaborative research should focus on determining whether antiemetic drugs cause more severe, probably rare, side effects. Further comparison of the antiemetic effect of one drug versus another is not a research priority.


Assuntos
Antieméticos/uso terapêutico , Náusea e Vômito Pós-Operatórios/prevenção & controle , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto
2.
Diam Relat Mater ; 61: 97-101, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26705376

RESUMO

In this report, an idea of integrating ultrananocrystalline diamond (UNCD) with pyrolytic carbon (PyC) -based mechanical heart valves, has been demonstrated. The report addresses the strategies to avoid graphitization and film delamination during the diamond coating. Raman and scratch tests showed that a UNCD film with high purity could adhere to the PyC substrate strongly. A thrombin generation study demonstrated an excellent biocompatibility of UNCD towards fresh human platelets. These results suggest that UNCD could be a good candidate of surface material for next generation heart valves and other implantable devices.

3.
Surf Coat Technol ; 302: 420-425, 2016 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-27867245

RESUMO

Ultrananocrystalline diamond (UNCD), an extremely smooth, low cost diamond coating was successfully developed herein for antithrombogenic application which requires high biocompatibility, low wear, low friction, and chemical inertness. The substrate materials utilized in the Jarvik 2000 ventricular assist device (VAD), silicon carbide and titanium alloy, provide an excellent substrate match for UNCD integration. The paper addresses the development of medical-quality UNCD films to significantly improve the knowledge base regarding the defect mechanisms of UNCD films, to reduce or eliminate known wear-inducing imperfections in the film, and to thoroughly characterize and test the films as well as assembled UNCD-coated VADs. After the defect reduction and seeding experiments to improve film adhesion and coating quality, the best candidate deposition method has been down-selected for coating and assembly of VAD parts from Jarvik Heart. The coated and assembled devices have been tested with mechanical and blood-simulating fluid hydrodynamic testing at Jarvik Heart for full verification of the new coating technology. UNCD interface takes advantage of combining unmatched durability and antithrombogenicity.

4.
Cochrane Database Syst Rev ; (5): CD009931, 2014 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-24801519

RESUMO

BACKGROUND: Permissive hypoxaemia describes a concept in which a lower level of arterial oxygenation (PaO2) than usual is accepted to avoid the detrimental effects of high fractional inspired oxygen and invasive mechanical ventilation. Currently however, no specific threshold is known that defines permissive hypoxaemia, and its use in adults remains formally untested. The importance of this systematic review is thus to determine whether any substantial evidence is available to support the notion that permissive hypoxaemia may improve clinical outcomes in mechanically ventilated critically ill patients. OBJECTIVES: We assessed whether permissive hypoxaemia (accepting a lower PaO2 than is current practice) in mechanically ventilated critically ill patients affects patient morbidity and mortality. We planned to conduct subgroup and sensitivity analyses and to examine the role of bias to determine the level of evidence provided. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) 2013, Issue 11, part of The Cochrane Library; MEDLINE (1954 to November 2013); EMBASE (1980 to November 2013); CINAHL (1982 to November 2013) and ISI Web of Science (1946 to November 2013). We combined the sensitive search strategies described in the Cochrane Handbook for Systematic Reviews of Interventions to search for randomized controlled trials (RCTs) in MEDLINE and EMBASE. For ongoing trials, we also searched the following databases: MetaRegister of ControlledTrials and the National Research Register. We applied no language restrictions. SELECTION CRITERIA: RCTs and quasi-RCTs that compared outcomes for mechanically ventilated critically ill participants, in which the intervention group was targeted to be hypoxaemic relative to the control group, and the control group was normoxaemic or was mildly hypoxaemic, were eligible for inclusion in this review. Exact values defining 'conventional' and 'permissive hypoxaemia' groupings were purposely not specified, and the manner in which these oxygenation goals were achieved also was not specified. We did state however that the intervention group required a target oxygenation level lower than that of the control group, and that the control group target levels should be in the range of normoxaemia or mild hypoxaemia (not hyperoxaemia). DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by The Cochrane Collaboration. Using the results of the above searches, two review authors (EG-K and KM) independently screened all titles and abstracts for eligibility and duplication. No discrepancies were encountered, nor was it necessary for review authors to contact the first author of any trial to ask for additional information. MAIN RESULTS: Our search strategy yielded a total of 2419 results. After exclusion of duplications, 1651 candidate studies were identified. Screening of titles and abstracts revealed that no studies met our inclusion criteria. AUTHORS' CONCLUSIONS: This comprehensive review failed to identify any relevant studies evaluating permissive hypoxaemia versus normoxaemia in mechanically ventilated critically ill participants. Therefore we are unable to support or refute the hypothesis that this treatment strategy is of benefit to patients.Given the substantial amount of provocative evidence derived from related clinical contexts (resuscitation, myocardial infarction, stroke), we believe that this review highlights an important unanswered question within critical care.  In the presence of two competing harms (hypoxia and hyperoxia), it will be important to carefully evaluate the safety and feasibility of permissive hypoxaemia before proceeding to efficacy and effectiveness trials.


Assuntos
Estado Terminal , Hipóxia , Oxigênio/sangue , Respiração Artificial , Adulto , Humanos , Valores de Referência
5.
Proc Natl Acad Sci U S A ; 108(3): 983-8, 2011 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-20884854

RESUMO

Carbon is an extremely versatile family of materials with a wide range of mechanical, optical, and mechanical properties, but many similarities in surface chemistry. As one of the most chemically stable materials known, carbon provides an outstanding platform for the development of highly tunable molecular and biomolecular interfaces. Photochemical grafting of alkenes has emerged as an attractive method for functionalizing surfaces of diamond, but many aspects of the surface chemistry and impact on biological recognition processes remain unexplored. Here we report investigations of the interaction of functionalized diamond surfaces with proteins and biological cells using X-ray photoelectron spectroscopy (XPS), atomic force microscopy, and fluorescence methods. XPS data show that functionalization of diamond with short ethylene glycol oligomers reduces the nonspecific binding of fibrinogen below the detection limit of XPS, estimated as > 97% reduction over H-terminated diamond. Measurements of different forms of diamond with different roughness are used to explore the influence of roughness on nonspecific binding onto H-terminated and ethylene glycol (EG)-terminated surfaces. Finally, we use XPS to characterize the chemical stability of Escherichia coli K12 antibodies on the surfaces of diamond and amine-functionalized glass. Our results show that antibody-modified diamond surfaces exhibit increased stability in XPS and that this is accompanied by retention of biological activity in cell-capture measurements. Our results demonstrate that surface chemistry on diamond and other carbon-based materials provides an excellent platform for biomolecular interfaces with high stability and high selectivity.


Assuntos
Anticorpos Antibacterianos/química , Físico-Química/métodos , Diamante/química , Fibrinogênio/química , Microscopia de Força Atômica/métodos , Espectroscopia Fotoeletrônica/métodos , Avidina/química , Escherichia coli K12/imunologia , Etilenoglicol , Fluorescência , Ligação Proteica , Propriedades de Superfície
6.
BMJ Open ; 14(3): e084164, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38471680

RESUMO

INTRODUCTION: Randomised controlled trials (RCTs) inform healthcare decisions. It is now apparent that some published RCTs contain false data and some appear to have been entirely fabricated. Systematic reviews are performed to identify and synthesise all RCTs that have been conducted on a given topic. While it is usual to assess methodological features of the RCTs in the process of undertaking a systematic review, it is not usual to consider whether the RCTs contain false data. Studies containing false data therefore go unnoticed and contribute to systematic review conclusions. The INveStigating ProblEmatic Clinical Trials in Systematic Reviews (INSPECT-SR) project will develop a tool to assess the trustworthiness of RCTs in systematic reviews of healthcare-related interventions. METHODS AND ANALYSIS: The INSPECT-SR tool will be developed using expert consensus in combination with empirical evidence, over five stages: (1) a survey of experts to assemble a comprehensive list of checks for detecting problematic RCTs, (2) an evaluation of the feasibility and impact of applying the checks to systematic reviews, (3) a Delphi survey to determine which of the checks are supported by expert consensus, culminating in, (4) a consensus meeting to select checks to be included in a draft tool and to determine its format and (5) prospective testing of the draft tool in the production of new health systematic reviews, to allow refinement based on user feedback. We anticipate that the INSPECT-SR tool will help researchers to identify problematic studies and will help patients by protecting them from the influence of false data on their healthcare. ETHICS AND DISSEMINATION: The University of Manchester ethics decision tool was used, and this returned the result that ethical approval was not required for this project (30 September 2022), which incorporates secondary research and surveys of professionals about subjects relating to their expertise. Informed consent will be obtained from all survey participants. All results will be published as open-access articles. The final tool will be made freely available.


Assuntos
Medicina Baseada em Evidências , Projetos de Pesquisa , Humanos , Consenso , Medicina Baseada em Evidências/métodos , Consentimento Livre e Esclarecido , Ensaios Clínicos Controlados Aleatórios como Assunto , Revisões Sistemáticas como Assunto
8.
Clin Orthop Relat Res ; 471(8): 2492-6, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23292888

RESUMO

BACKGROUND: All patients considering joint-preserving hip arthroscopy should be educated on the risk of THA after arthroscopy. The degree of radiographic osteoarthritis predicts subsequent THA. To provide patients with the best information, the best radiographic measure that predicts THA after hip arthroscopy should be identified. QUESTIONS/PURPOSES: We therefore determined if Tönnis grade, Kellgren-Lawrence grade, or joint space narrowing was superior in predicting THA after hip arthroscopy. METHODS: We retrospectively reviewed 203 patients 50 years of age or older treated with hip arthroscopy between March 2007 and October 2010. Of these, 96 patients met the study inclusion criteria. Sixty-five did not undergo THAs during the followup time (non-THA group) and 31 patients did (THA group). We determined Tönnis grade, Kellgren-Lawrence grade, and/or joint space narrowing before arthroscopy. The median followup for the non-THA group was 54 months (95% confidence interval, 49.9-58.9 months). RESULTS: In 81% of the patients, joint space accurately predicted THA or non-THA, whereas Kellgren-Lawrence was accurate in 73% and Tönnis grade was accurate in 65%. On binary logistic regression, the only predictor (r(2) = 0.45) of THA was joint space of 2 mm or less. CONCLUSIONS: Measuring joint space by determining if any measurement is 2 mm or less predicts patients progressing to THA after hip arthroscopy approximately 80% of the time. At this early time point, joint space measurements were the most accurate predictor of THA and should be used in patient education to define the risk of early failure from hip arthroscopy.


Assuntos
Artroplastia de Quadril , Artroscopia , Articulação do Quadril/cirurgia , Osteoartrite do Quadril/cirurgia , Idoso , Artroscopia/efeitos adversos , Estudos Transversais , Feminino , Articulação do Quadril/diagnóstico por imagem , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Osteoartrite do Quadril/diagnóstico , Valor Preditivo dos Testes , Radiografia , Sistema de Registros , Reoperação , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Índice de Gravidade de Doença , Falha de Tratamento
9.
medRxiv ; 2023 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-37873409

RESUMO

Introduction: Randomised controlled trials (RCTs) inform healthcare decisions. It is now apparent that some published RCTs contain false data and some appear to have been entirely fabricated. Systematic reviews are performed to identify and synthesise all RCTs that have been conducted on a given topic. While it is usual to assess methodological features of the RCTs in the process of undertaking a systematic review, it is not usual to consider whether the RCTs contain false data. Studies containing false data therefore go unnoticed and contribute to systematic review conclusions. The INSPECT-SR project will develop a tool to assess the trustworthiness of RCTs in systematic reviews of healthcare related interventions. Methods and analysis: The INSPECT-SR tool will be developed using expert consensus in combination with empirical evidence, over five stages: 1) a survey of experts to assemble a comprehensive list of checks for detecting problematic RCTs, 2) an evaluation of the feasibility and impact of applying the checks to systematic reviews, 3) a Delphi survey to determine which of the checks are supported by expert consensus, culminating in 4) a consensus meeting to select checks to be included in a draft tool and to determine its format, 5) prospective testing of the draft tool in the production of new health systematic reviews, to allow refinement based on user feedback. We anticipate that the INSPECT-SR tool will help researchers to identify problematic studies, and will help patients by protecting them from the influence of false data on their healthcare.

10.
Nanotechnology ; 23(49): 495302, 2012 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-23149947

RESUMO

We report a wear-resistant ultrananocrystalline (UNCD) diamond tip integrated onto a heated atomic force microscope (AFM) cantilever and UNCD tips integrated into arrays of heated AFM cantilevers. The UNCD tips are batch-fabricated and have apex radii of approximately 10 nm and heights up to 7 µm. The solid-state heater can reach temperatures above 600 °C and is also a resistive temperature sensor. The tips were shown to be wear resistant throughout 1.2 m of scanning on a single-crystal silicon grating at a force of 200 nN and a speed of 10 µm s(-1). Under the same conditions, a silicon tip was completely blunted. We demonstrate the use of these heated cantilevers for thermal imaging in both contact mode and intermittent contact mode, with a vertical imaging resolution of 1.9 nm. The potential application to nanolithography was also demonstrated, as the tip wrote hundreds of polyethylene nanostructures.


Assuntos
Diamante/química , Calefação/instrumentação , Microscopia de Força Atômica/instrumentação , Nanoestruturas/química , Nanotecnologia/instrumentação , Transdutores , Cristalização/métodos , Desenho de Equipamento , Análise de Falha de Equipamento , Teste de Materiais , Nanoestruturas/ultraestrutura , Integração de Sistemas
11.
Colorectal Dis ; 19(1): 64-66, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-28054756
12.
Adv Funct Mater ; 21(6): 1040-1050, 2011 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-21949497

RESUMO

Immunoassays for detection of bacterial pathogens rely on the selectivity and stability of bio-recognition elements such as antibodies tethered to sensor surfaces. The search for novel surfaces that improve the stability of biomolecules and assay performance has been pursued for a long time. However, the anticipated improvements in stability have not been realized in practice under physiological conditions because the surface functionalization layers on commonly used substrates, silica and gold, are themselves unstable on time scales of days. In this paper, we show that covalent linking of antibodies to diamond surfaces leads to substantial improvements in biological activity of proteins as measured by the ability to selectively capture cells of the pathogenic bacterium Escherichia coli O157:H7 even after exposure to buffer solutions at 37 °C for extended periods of time, approaching 2 weeks. Our results from ELISA, XPS, fluorescence microscopy, and MD simulations suggest that by using highly stable surface chemistry and controlling the nanoscale organization of the antibodies on the surface, it is possible to achieve significant improvements in biological activity and stability. Our findings can be easily extended to functionalization of micro and nanodimensional sensors and structures of biomedical diagnostic and therapeutic interest.

13.
Arthroscopy ; 27(2): 252-69, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21266276

RESUMO

PURPOSE: To analyze the current approaches to the surgical management of symptomatic femoroacetabular impingement (FAI). METHODS: Thirteen relevant queries were used in four search engines (PubMed, EMBASE, Ovid, and the Cochrane Review) with a resultant 5,856 articles. Eighteen peer-reviewed treatment outcome studies met the inclusion criteria with minimum 1-year follow-up of the surgical treatment of skeletal pathoanatomy and associated chondrolabral pathology in skeletally mature patients with FAI. RESULTS: There were 6 open surgical dislocation, 4 mini-open, and 8 arthroscopic studies, all with Levels of Evidence III or IV. The only prospective studies were in the arthroscopic category. Outcome data were extracted and analyzed with respect to surgical efficacy, failure rates, and complications. CONCLUSIONS: The open dislocation, mini-open, and arthroscopic methods for treating symptomatic FAI are effective in improving pain and function in short-term to midterm studies and are relatively safe procedures. The historical gold standard of open dislocation surgery had a comparatively high major complication rate primarily because of trochanteric osteotomy-related issues. The mini-open method showed comparable efficacy but a significant incidence of iatrogenic injury to the lateral femoral cutaneous nerve in some studies. The arthroscopic method had surgical outcomes equal to or better than the other methods with a lower rate of major complications when performed by experienced surgeons.


Assuntos
Impacto Femoroacetabular/cirurgia , Procedimentos Ortopédicos , Artroscopia , Humanos , Procedimentos Cirúrgicos Minimamente Invasivos , Procedimentos Ortopédicos/métodos , Resultado do Tratamento
14.
Eur J Anaesthesiol ; 28(10): 684-722, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21885981

RESUMO

The purpose of these guidelines on the preoperative evaluation of the adult non-cardiac surgery patient is to present recommendations based on available relevant clinical evidence. The ultimate aims of preoperative evaluation are two-fold. First, we aim to identify those patients for whom the perioperative period may constitute an increased risk of morbidity and mortality, aside from the risks associated with the underlying disease. Second, this should help us to design perioperative strategies that aim to reduce additional perioperative risks. Very few well performed randomised studies on the topic are available and many recommendations rely heavily on expert opinion and are adapted specifically to the healthcare systems in individual countries. This report aims to provide an overview of current knowledge on the subject with an assessment of the quality of the evidence in order to allow anaesthetists all over Europe to integrate - wherever possible - this knowledge into daily patient care. The Guidelines Committee of the European Society of Anaesthesiology (ESA) formed a task force with members of subcommittees of scientific subcommittees and individual members of the ESA. Electronic databases were searched from the year 2000 until July 2010 without language restrictions. These searches produced 15 425 abstracts. Relevant systematic reviews with meta-analyses, randomised controlled trials, cohort studies, case-control studies and cross-sectional surveys were selected. The Scottish Intercollegiate Guidelines Network grading system was used to assess the level of evidence and to grade recommendations. The final draft guideline was posted on the ESA website for 4 weeks and the link was sent to all ESA members, individual or national (thus including most European national anaesthesia societies). Comments were collated and the guidelines amended as appropriate. When the final draft was complete, the Guidelines Committee and ESA Board ratified the guidelines.


Assuntos
Anestesiologia/métodos , Anestesiologia/normas , Guias de Prática Clínica como Assunto , Adulto , Cardiologia/métodos , Europa (Continente) , Medicina Baseada em Evidências , Feminino , Cardiopatias/complicações , Humanos , Masculino , Período Pré-Operatório , Ensaios Clínicos Controlados Aleatórios como Assunto , Risco , Fatores de Risco , Inquéritos e Questionários
15.
Lab Chip ; 10(9): 1135-41, 2010 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-20390131

RESUMO

This paper presents the design and application of microcantilever heaters for biochemical applications. Thermal lysis of biological cells was demonstrated as a specific example. The microcantilever heaters, fabricated from selectively doped single crystal silicon, provide local resistive heating with highly uniform temperature distribution across the cantilevers. Very importantly, the microcantilever heaters were coated with a layer of 100 nm thick electrically insulating ultrananocrystalline diamond (UNCD) layer used for cell immobilization on the cantilever surface. Fibroblast cells or bacterial cells were immobilized on the UNCD/cantilever surfaces and thermal lysis was demonstrated via optical fluorescence microscopy. Upon electrical heating of the cantilever structures to 93 degrees C for 30 seconds, fibroblast cell and nuclear membrane were compromised and the cells were lysed. Over 90% of viable bacteria were also lysed after 15 seconds of heating at 93 degrees C. This work demonstrates the utility of silicon-UNCD heated microcantilevers for rapid cell lysis and forms the basis for other rapid and localized temperature-regulated microbiological experiments in cantilever-based lab on chip applications.


Assuntos
Fracionamento Celular/instrumentação , Diamante/química , Eletrônica/instrumentação , Calefação/instrumentação , Sistemas Microeletromecânicos/instrumentação , Silício/química , Transdutores , Desenho de Equipamento , Análise de Falha de Equipamento , Miniaturização , Temperatura
16.
Clin Orthop Relat Res ; 467(3): 666-75, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19048356

RESUMO

Radiographic evaluation provides essential information regarding the diagnosis and treatment of musculoskeletal disorders. We evaluated the ability of hip specialists to reliably identify important radiographic features and to make a diagnosis based on plain radiographs alone. Five hip specialists and one fellow performed a blinded radiographic review of 25 control hips, 25 hips with developmental dysplasia (DDH), and 27 with femoroacetabular impingement (FAI). On two separate occasions, readers assessed acetabular version, inclination and depth, position of the femoral head center, head sphericity, head-neck offset, Tönnis grade, and joint congruency. Observers made a diagnosis categorizing each hip as normal, dysplastic, FAI, or combined DDH and FAI (features of both). Reliability was determined using Cohen's kappa coefficient. Intraobserver values were highest for acetabular inclination (kappa = 0.72) and determination of femoral head center position (kappa = 0.77). Interobserver reliability values were highest for acetabular inclination (kappa = 0.61) and Tönnis osteoarthritis grade (kappa = 0.59). All other measurements, including diagnosis, had kappa values less than 0.55. We concluded many of the standard radiographic parameters used to diagnose DDH and/or FAI are not reproducible. Accordingly, a more clear set of definitions and measurements must be developed to allow for more reliable diagnosis of early hip disease.


Assuntos
Acetábulo/diagnóstico por imagem , Artrografia , Fêmur/diagnóstico por imagem , Luxação Congênita de Quadril/diagnóstico por imagem , Articulação do Quadril/diagnóstico por imagem , Acetábulo/fisiopatologia , Diagnóstico Precoce , Fêmur/fisiopatologia , Luxação Congênita de Quadril/fisiopatologia , Articulação do Quadril/fisiopatologia , Humanos , Variações Dependentes do Observador , Valor Preditivo dos Testes , Amplitude de Movimento Articular , Reprodutibilidade dos Testes , Estudos Retrospectivos , Índice de Gravidade de Doença
18.
J Knee Surg ; 20(4): 312-22, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17993076

RESUMO

Revision ACL surgery is a technically demanding enterprise that requires meticulous preoperative planning and tempered postoperative expectations on the patient's part. Despite the complexities of the procedure, it is becoming more common as an increasing number of primary ACL reconstructions are being performed, expanding the pool of patients at risk for failure. Candidates for revision surgery should be selected carefully, focusing on those patients with recurrent instability rather than pain as their primary complaint. A thorough history and physical examination is essential, taking care to identify additional patholaxity that might contribute to a failed ACL reconstruction. To optimize outcomes, surgeons must take care to avoid common pitfalls in index and revision procedures. Femoral and tibial tunnels should be positioned anatomically, and staged bone grafting procedures should be considered if revision graft fixation may be compromised by tunnel defects. The type of graft must be carefully selected, appropriately tensioned, and securely fixed. Surgeons should have a number of techniques and instruments at their disposal for performing each of these steps, as the highly variable presentation of failed ACL reconstructions demands a versatile approach. Ultimately, with cautious rehabilitation, these techniques will allow for restoration of knee stability and, in many cases, an improvement in activity level.


Assuntos
Ligamento Cruzado Anterior/cirurgia , Complicações Pós-Operatórias/cirurgia , Tendões/transplante , Lesões do Ligamento Cruzado Anterior , Artroscopia , Humanos , Instabilidade Articular/etiologia , Instabilidade Articular/cirurgia , Traumatismos do Joelho/diagnóstico , Procedimentos Ortopédicos/métodos , Complicações Pós-Operatórias/reabilitação , Reoperação/métodos , Falha de Tratamento
19.
J Biomed Mater Res B Appl Biomater ; 77(2): 273-81, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16245292

RESUMO

In this work, ultrananocrystalline diamond (UNCD) thin films were evaluated for use as hermetic and bioinert coatings for a retinal microchip. These films were deposited on highly conductive Si substrates at different temperatures (from 400 to 800 degrees C), using microwave plasma enhanced chemical vapor deposition with argon-rich Ar/CH4 gas mixtures and different relative amounts of hydrogen (0-20%). Scanning electron microscopy studies showed that all the films are dense and continuous. Results of cyclic voltammetry test revealed that when there was <2% of hydrogen in the plasma, the film obtained renders the surface electrochemically inactive, with very low leakage currents ( approximately 4 x 10(-7) A/cm2 at +/-5 V). In addition, in vivo tests of the UNCD-coated Si samples were performed by implanting them in the eyes of rabbits for 4-6 months within the eye physiological environment. According to all these results, it was concluded that UNCD is a promising candidate for use as the encapsulating coatings for implantable retinal microelectronic devices.


Assuntos
Materiais Revestidos Biocompatíveis/química , Diamante , Eletrônica Médica , Próteses e Implantes , Retina , Animais , Implantes Experimentais , Microscopia Eletrônica de Varredura , Nanoestruturas , Coelhos , Silício , Propriedades de Superfície
20.
Small ; 1(8-9): 866-74, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17193541

RESUMO

A hard, low-wear probe for contact-mode writing techniques, such as dip-pen nanolithography (DPN), was fabricated using ultrananocrystalline diamond (UNCD). Molding within anisotropically etched and oxidized pyramidal pits in silicon was used to obtain diamond tips with radii down to 30 nm through growth of UNCD films followed by selective etching of the silicon template substrate. The probes were monolithically integrated with diamond cantilevers and subsequently integrated into a chip body obtained by metal electroforming. The probes were characterized in terms of their mechanical properties, wear, and atomic force microscopy imaging capabilities. The developed probes performed exceptionally well in DPN molecular writing/imaging mode. Furthermore, the integration of UNCD films with appropriate substrates and the use of directed microfabrication techniques are particularly suitable for fabrication of one- and two-dimensional arrays of probes that can be used for massive parallel fabrication of nanostructures by the DPN method.


Assuntos
Materiais Revestidos Biocompatíveis , Diamante , Ouro/química , Microscopia de Força Atômica/métodos , Nanoestruturas , Nanotecnologia/métodos , Cristalização , Eletroquímica/métodos , Teste de Materiais , Microscopia Eletrônica de Varredura , Semicondutores , Silício , Eletricidade Estática , Propriedades de Superfície
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA