Activating two-dimensional semiconductors for photocatalysis: a cross-dimensional strategy.

The emerging two-dimensional (2D) semiconductors substantially extend materials bases for versatile applications such as semiconductor photocatalysis demanding semiconductive matrices and large surface areas. The dimensionality, while endowing 2D semiconductors the unique properties to host photocatalytic functionality of pollutant removal and hydrogen evolution, hurdles the activation paths to form heterogenous photocatalysts where the photochemical processes are normally superior over these on the mono-compositional counterparts. In this perspective, we present a cross-dimensional strategy to employ thenD (n= 0-2) clusters or nanomaterials as activation partners to boost the photocatalytic activities of the 2D semiconductors. The formation principles of heterogenous photocatalysts are illustrated specifically for the 2D matrices, followed by selection criteria of them among the vast 2D database. The computer investigations are illustrated in the density functional theory route and machine learning benefitted from the vast samples in the 2D library. Synthetic realizations and characterizations of the 2D heterogenous systems are introduced with an emphasis on chemical methods and advanced techniques to understand materials and mechanistic studies. The perspective outlooks cross-dimensional activation strategies of the 2D materials for other applications such as CO2removal, and materials matrices in other dimensions which may inspire incoming research within these fields.

Building a network for multicenter, prospective research of central nervous system infections in South America: Process and lessons learned.

Multicenter collaborative networks are essential for advancing research and improving clinical care for a variety of conditions. Research networks are particularly important for central nervous system infections, which remain difficult to study due to their sporadic occurrence and requirement for collection and testing of cerebrospinal fluid. Establishment of long-term research networks in resource-limited areas also facilitates diagnostic capacity building, surveillance for emerging pathogens, and provision of appropriate treatment where needed. We review our experience developing a research network for encephalitis among twelve hospitals in five Peruvian cities since 2009. We provide practical suggestions to aid other groups interested in advancing research on central nervous system infections in resource-limited areas.

Adaptación del modo de autoconcepto en usuarios con diabetes tipo 2 de una unidad de primer nivel / Adaptation of the self-concept mode in users with diabetes type 2 in a first level unit / Adaptação do modo de autoconceito em usuários com diabetes tipo 2 de uma unidade de primeiro nível

Objetivo Comparar el nivel de adaptación del autoconcepto (NAA) en las personas que viven con Diabetes mellitus tipo 2 (DT2), en dos escenarios de una unidad de primer nivel. Metodología Investigación descriptiva, correlacional, comparativa y transversal con muestreo por conveniencia; se conformó por adultos con DT2 que asisten a control mensual y al grupo de ayuda mutua (GAM) en una unidad de primer nivel. Se aplicó cédula de datos generales e instrumento Viveros03 (a=.85); se realizó valoración antropométrica y glucemia capilar. El análisis de datos fue con SPSS v. 20. La comprobación de hipótesis fue mediante Shapiro-Wilk, T-student y Ji cuadrada. Resultados Se trabajó con 50 sujetos, 25 del GAM (Grupo A) y 25 de control ambulatorio (Grupo B). El NAA del grupo A fue 60% integrado y del B fue de 68% compensatorio, con diferencia significativa entre ambos grupos (p=0.02). Los estímulos contextuales como control glucémico, años de diagnóstico y tratamiento no demostraron dependencia (p >.05), contrario a los antecedentes familiares con diabetes y pertenecer al GAM en donde sí hubo relación (p= <.05). Conclusión El NAA fue mejor en el GAM, la valoración positiva del autoconcepto tuvo un mayor impacto, así mismo en el GAM, los antecedentes familiares son estímulos contextuales que permiten la adaptación de manera positiva.

Objective To compare the level of Adaptation of the Self-Concept (ASC) in persons suffering from Diabetes mellitus type 2 (DT2) in two locations at a first level unit. Methodology This is a descriptive, correlational, comparative, and transversal research with a sample by convenience of adults with DT2 attending to a monthly control, and to a Mutual Support Group MSG, both in a first level unit. The general data register and the Viveros03 instrument (a =.85) were used. Anthropometric and capillary glycemic level assessments were performed. Data were analyzed through SPSS v.20. The hypothesis was verified using Shapiro-Wilk, T-student and Chi square tests. Results There were 50 participants, the 25 in the MSG were assigned to group A, while the other 25 constituted the ambulatory and group B. ASC in group A was 60% while 68% in group B; the difference was significant at p = 0.002. Contextual stimuli such as capillary glycemic level, and years of diagnosis and treatment did not show dependence (p > .05) contrary to family diabetes background, and belonging to the MSG, which did show an association (p=<.05). Conclusion ASC was better among those in the MSG, while family background promoted a better adaptation as well.

Objetivo Comparar o nível de adaptação do autoconceito (NAA) nas pessoas que vivem com Diabetes mellitus tipo 2 (DT2), em dois cenários de uma unidade de primeiro nível. Metodologia Pesquisa descritiva, correlacional, comparativa e transversal com amostragem por conveniência; conformou-se por adultos com DT2 que assistem a controle mensal e ao grupo de ajuda mutua (GAM) em uma unidade de primeiro nível. Aplicou-se cédula de dados generais e instrumento Viveros03 (a=.85); realizou-se valorização antropométrica e glicemia capilar. A análise de dados foi com SPSS v. 20. A comprobação de hipótese foi mediante Shapiro-Wilk, T-student e Ji cuadrada. Resultados Trabalhou-se com 50 indivíduos, 25 do GAM (Grupo A) e 25 de controle ambulatório (Grupo B). O NAA do grupo A foi 60% integrado e do B foi de 68% compensatório, com diferença significativa entre ambos os grupos (p=0.02). Os estímulos contextuais como controle glicêmico, anos de diagnóstico e tratamento não demonstraram dependência (p > .05), contrário aos antecedentes familiares com diabetes e pertencer ao GAM onde houve uma relação (p=< 05). Conclusão O NAA foi melhor no GAM, a avaliação positiva do autoconceito teve um maior impacto, assim mesmo no GAM, os antecedentes familiares são estímulos contextuais que permitem a adaptação de maneira positiva.

Tay bridge and extracellular-regulated kinase activity are required for motoneuron function in the Drosophila neural system.

Extracellular regulated kinase (Erk) activity is required during neural development for the specification of cell fates in neuroblasts and neuronal lineages, and also regulates several aspects of the activity and survival of mature neurons. The activation of Erk is regulated at multiple levels by kinases and phosphatases that alter its phosphorylation state and by other proteins that regulate its subcellular localization. Here, we find that tay bridge (tay), a negative regulator of Erk in Drosophila imaginal discs, is required in the motoneurons to regulate the number and size of neuromuscular synapses in these cells. The expression of Tay is maximal in motoneurons with low levels of activated ERK, suggesting that Tay modulates the activity of Erk in these cells. We also found that loss of tay expression and increased Erk activity specifically in the motoneurons cause a reversible decrease in walking speed. Impaired motoneurons activity may be caused by alterations in the functionality and number of synaptic boutons developing at the neuromuscular junction in tay mutants.

Excellent translational research in oncology: A journey towards novel and more effective anti-cancer therapies.

Comprehensive Cancer Centres (CCCs) serve as critical drivers for improving cancer survival. In Europe, we have developed an Excellence Designation System (EDS) consisting of criteria to assess "excellence" of CCCs in translational research (bench to bedside and back), with the expectation that many European CCCs will aspire to this status.

A case-control study of post-operative endophthalmitis diagnosed at a Spanish hospital over a 13-year-period.

A retrospective case-control study of patients who had undergone cataract extraction at a Spanish hospital over a 13-year period was conducted to identify the risk factors for developing post-operative endophthalmitis (POE). During the study period, the type of antibiotic prophylaxis was changed from subconjunctival gentamicin to the addition of both vancomycin and gentamicin to the irrigating solution. The overall incidence of POE was 0·19% (35 cases/18 287 operations). For the period prior to the change in antibiotic prophylaxis, the incidence rate of POE was 3·4 cases/1000 operations while in the latter period the incidence rate decreased to 0·34 cases/1000 operations. All patients who presented a virulent microorganism had a final visual acuity worse than 20/200. The only significant risk factor identified was the type of prophylaxis used (odds ratio 1·97, 95% confidence interval 0·94-4·14, P = 0·07). There were no significant differences between cases and controls although choice of surgeon approached significance.

Biotribocorrosion (tribo-electrochemical) characterization of anodized titanium biomaterial containing calcium and phosphorus before and after osteoblastic cell culture.

The purpose of this study was to investigate the relationship between the osteoblastic cells behavior and biotribocorrosion phenomena on bioactive titanium (Ti). Ti substrates submitted to bioactive anodic oxidation and etching treatments were cultured up to 28 days with MG63 osteoblast-like cells. Important parameters of in vitro bone-like tissue formation were assessed. Although no major differences were observed between the surfaces topography (both rough) and wettability (both hydrophobic), a significant increase in cell attachment and differentiation was detected on the anodized substrates as product of favorable surface morphology and chemical composition. Alkaline phosphatase production has increased (≈20 nmol/min/mg of protein) on the anodized materials, while phosphate concentration has reached the double of the etched material and calcium production increased (over 20 µg/mL). The mechanical and biological stability of the anodic surfaces were also put to test through biotribocorrosion sliding solicitations, putting in evidence the resistance of the anodic layer and the cells capacity of regeneration after implant degradation. The Ti osteointegration abilities were also confirmed by the development of strong cell-biomaterial bonds at the interface, on both substrates. By combining the biological and mechanical results, the anodized Ti can be considered a viable option for dentistry.

[Microbiological study of infectious endophthalmitis with positive culture within a 13 year-period]. / Estudio microbiológico de los casos de endoftalmitis infecciosa con cultivo positivo en un periodo de 13 años.

INTRODUCTION: Our objectives are to describe the microbial spectrum and antimicrobial susceptibility of isolates from patients with culture-proven endophthalmitis. MATERIAL AND METHODS: Retrospective study of patients with microbiological diagnosis of endophthalmitis treated at the Ophthalmology Department of the General Hospital La Mancha Centro in the period 1996-2008. The identification of isolates was performed using the automated VITEK-2® and Api galleries (bioMérieux, Spain SA). The antimicrobial susceptibility was performed by the VITEK-2® system (bioMérieux, Spain SA), E-test strips (MIC Test Strip, Liofilchem, Italy) and Sensititre® YeastOne trading system (Trek Diagnostic Systems, Ohio, USA) for Candida species. RESULTS: Forty four (70%) of 63 cases of endophthalmitis were culture positive. Gram-positive bacteria were much more common than gram-negative bacteria in both postoperative endophthalmitis (POE) and post-traumatic endophthalmitis (PTE). Staphylococcus epidermidis was predominant in POE, while Bacillus sp. predominated in the PTE; furthermore, the 75% of total fungal isolates corresponded to postraumatic cases. The isolated strains showed 100% susceptibility to vancomycin, ceftazidime and amikacin, while resistance to ciprofloxacin was greater than 15%. The empirical antifungal therapy failed in 50% of cases. The visual prognosis was significantly less favorable in the PTE. CONCLUSIONS: Based on the susceptibility of our isolates, vancomycin, ceftazidime and amikacin are good choices for empirical treatment of endophthalmitis, unlike ciprofloxacin. We recommend conducting antifungal prophylaxis after penetrating ocular trauma in a rural environment.

Adhesivo de fibrina intracameral como tratamiento de perforación corneal espontánea / Intracameral fibrin glue in spontaneous corneal perforation

CASO CLÍNICO: Paciente varón de 70 años remitido a nuestro servicio por una perforación corneal en el ojo izquierdo (OI) de posible origen herpético. Se procedió a su reparación mediante la introducción de pegamento tisular de fibrina (Tissucol®) en cámara anterior, colocación de parche de membrana amniótica y lente terapéutica de gran diámetro. En el postoperatorio presentó cierre de la perforación y resolución de la fibrina intracameral sin daño endotelial. DISCUSIÓN: El pegamento tisular de fibrina puede ser utilizado en cámara anterior para tratar perforaciones corneales con excelentes resultados

CASE REPORT: A 70-year-old male was referred to our department due to a herpetic corneal perforation in the left eye. The perforation was healed with intracameral fibrin tissue sealant (Tissucol®), an amniotic membrane, and a large diameter soft contact lens. Postoperatively there were complete dissolution of the fibrin sealant and closure of the perforation without endothelial damage. DISCUSSION: Intracameral fibrin glue may be effective in the closure of corneal perforations

[Intracameral fibrin glue in spontaneous corneal perforation]. / Adhesivo de fibrina intracameral como tratamiento de perforación corneal espontánea.

CASE REPORT: A 70-year-old male was referred to our department due to a herpetic corneal perforation in the left eye. The perforation was healed with intracameral fibrin tissue sealant (Tissucol(®)), an amniotic membrane, and a large diameter soft contact lens. Postoperatively there were complete dissolution of the fibrin sealant and closure of the perforation without endothelial damage. DISCUSSION: Intracameral fibrin glue may be effective in the closure of corneal perforations.

[Gallstone disease post-radical gastrectomy for gastric adenocarcinoma at the National Institute of Neoplastic Diseases, January 1990 to December 2000]. / Litiasis vesícular post- gastrectomía radical por adenocarcinoma gástrico en el Instituto Nacional de Enfermedades Neoplásicas, enero 1990 a diciembre del 2000.

SUBJECT: To determinate the frecuency and the time of development of the gallbladder stones in gastrectomy post-operated patients with stomach adenocarcinoma at The National Cancer Institute in Lima, Peru. METHODS: In an observational, descriptive and retrospective case series design, 148 patiens' files who underwent gastrectomy for stomach adenocarcinoma in the National Cancer Institue of Lima during 1990 and 2000, have been reviewed looking for the development of gallbladder stones. RESULTS: A total de 148 patients were involved in this study. 29 of them (19.6%) develop gallbladder stones during the (x years of) follow up vs 119 (80.9%) . The mean age ot the 29 patients with gallbladder stones were 59.9 years ans 18 of them were female and 11 male.\The mean time of develop gallbladder stones was 3.1 years.According to the type of surgery, 14 patient wiht gallbladder stones underwent to subtotal gastrectomy and 15 to total gastrectomy. CONCLUSIONS: The frecuency of gallbladder stones post gastrectomy in this study was 19.6%. The mean time of the develop and diagnosis of litiasis was 3.1 years.To perform the colecistectomy at the same time of the gastrectomy could be an important decision in patients with high risk of gallstones and gallbladder cancer.We need furthermore studies to have conclusions about the risk factors.

Litiasis vesícular post-gastrectomía radical por adenocarcinoma gástrico en el Instituto Nacional de Enfermedades Neoplásicas, enero 1990 a diciembre del 2000 / Gallstone disease post-radical gastrectomy for gastric adenocarcinoma at the National Institute of Neoplastic Diseases, January 1990 to December 2000

OBJETIVO: Determinar la frecuencia de litiasis vesicular en pacientes post-operados con gastrectomía por adenocarcinoma gástrico, determinar el tiempo de aparición de litiasis vesicular en pacientes gastrectomizados por Adenocarcinoma Gástrico. MÉTODOS: Se realizo un estudio observacional, descriptivo retrospectivo. Se revisó un total de 148 historias clínicas de pacientes sometidos a gastrectomía por adenocarcinoma gástrico en el Instituto Nacional de Enfermedades Neoplásicas en el periodo de 1990 al 2000. RESULTADOS: De los 148 casos de pacientes post gastrectomizados por adenocarcinoma gástrico que fueron enrolados, 29(19.6 por ciento) presentaron litiasis vesicular versus 119(80.9 por ciento) que no presentaron litiasis vesicular como complicación post gastrectomía. La media de edad de 29 pacientes con litiasis vesicular post gastrectomía por adenocarcinoma gástrico fue de 59.9años (min. 39años máx.74años). La distribución de la litiasis vesicular en relación al sexo fue, femenino 18(62.1 por ciento) casos y masculino 11(37.9 por ciento) casos. La media del tiempo de aparición de la litiasis vesicular post gastrectomía fue de 3.1 años, para el sexo masculino 2.7años y para el sexo femenino de 3.3 años. Según el tipo de cirugía se presento litiasis vesicular en 14 pacientes que fueron sometidos a Gastrectomía Subtotal Distal y a 15 pacientes a los que se les practicó Gastrectomía Total. CONCLUSIONES: la Frecuencia de litiasis vesicular post gastrectomía fue de 19.6 por ciento. El periodo de aparición de colelitiasis fue de 3.1 años. La colecistectomía podría ser una toma de decisión importante en pacientes con alto riesgo de litiasis y cáncer vesicular post gastrectomía. El presente trabajo de investigación invita a realizar otros estudios de tipo cohorte en el cual se determine el factor de riesgo principal para la aparición de esta complicación.

SUBJECT: To determinate the frecuency and the time of development of the gallbladder stones in gastrectomy post-operated patients with stomach adenocarcinoma at The National Cancer Institute in Lima, Peru. METHODS: In an observational, descriptive and retrospective case series design, 148 patiens' files who underwent gastrectomy for stomach adenocarcinoma in the National Cancer Institue of Lima during 1990 and 2000, have been reviewed looking for the development of gallbladder stones. RESULTS: A total de 148 patients were involved in this study. 29 of them (19.6 percent) develop gallbladder stones during the (x years of) follow up vs 119(80.9 percent). The mean age ot the 29 patients with gallbladder stones were 59.9 years ans 18 of them were female and 11 male./The mean time of develop gallbladder stones was 3.1 years. According to the type of surgery, 14 patient wiht gallbladder stones underwent to subtotal gastrectomy and 15 to total gastrectomy. CONCLUSIONS The frecuency of gallbladder stones post gastrectomy in this study was 19.6 percent. The mean time of the develop and diagnosis of litiasis was 3.1 years. To perform the colecistectomy at the same time of the gastrectomy could be an important decision in patients with high risk of gallstones and gallbladder cancer. We need furthermore studies to have conclusions about the risk factors.

Biofilms inducing ultra-low friction on titanium.

Biofilm formation is widely reported in the literature as a problem in the healthcare, environmental, and industrial sectors. However, the role of biofilms in sliding contacts remains unclear. Friction during sliding was analyzed for titanium covered with mixed biofilms consisting of Streptococcus mutans and Candida albicans. The morphology of biofilms on titanium surfaces was evaluated before, during, and after sliding tests. Very low friction was recorded on titanium immersed in artificial saliva and sliding against alumina in the presence of biofilms. The complex structure of biofilms, which consist of microbial cells and their hydrated exopolymeric matrix, acts like a lubricant. A low friction in sliding contacts may have major significance in the medical field. The composition and structure of biofilms are shown to be key factors for an understanding of friction behavior of dental implant connections and prosthetic joints. For instance, a loss of mechanical integrity of dental implant internal connections may occur as a consequence of the decrease in friction caused by biofilm formation. Consequently, the study of the exopolymeric matrix can be important for the development of high-performance novel joint-based systems for medical and other engineering applications.

Do oral biofilms influence the wear and corrosion behavior of titanium?

The main aim of this work was to study the simultaneous wear-corrosion of titanium (Ti) in the presence of biofilms composed of Streptococcus mutans and Candida albicans. Both organisms were separately grown in specific growth media, and then mixed in a medium supplemented with a high sucrose concentration. Corrosion and tribocorrosion tests were performed after 48 h and 216 h of biofilm growth. Electrochemical corrosion tests indicated a decrease in the corrosion resistance of Ti in the presence of the biofilms although the TiO(2) film presented the characteristics of a compact oxide film. While the open circuit potential of Ti indicated a tendency to corrosion in the presence of the biofilms, tribocorrosion tests revealed a low friction on biofilm covered Ti. The properties of the biofilms were similar to those of the lubricant agents used to decrease the wear rate of materials. However, the pH-lowering promoted by microbial species, can lead to corrosion of Ti-based oral rehabilitation systems.

Characterisation and tribological investigation on thermally processed nanostructured Fe-based and Cu-based cermet materials.

The feasibility of achieving a nanostructured material after different thermal processing of nanosized powders is presented. The thermal processing was done by either atmospheric plasma spraying, laser sintering, or extrusion followed by hot isostatic pressing. The structural characterisation of such thermally processed nanostructured Fe-based and Cu-based metallic or Al2O3 reinforced cermets, confirmed the retention of a nanostructure after each of these thermal processes. Hardness measurements confirmed an increased hardness as expected in the case that nanostructuring is achieved. The role of grain boundaries and second phase particles on the retention of the nanostructure after thermal processing is discussed. Finally, the possible benefit of nanostructuring on the friction and wear behaviour of materials in sliding tests against corundum in ambient air is reported and discussed.

In situ modification of activated carbons developed from a native invasive wood on removal of trace toxic metals from wastewater.

Activated carbons were developed by phosphoric acid activation of sawdust from Prosopis ruscifolia wood, an indigenous invasive species of degraded lands, at moderate conditions (acid/precursor ratio=2, 450 degrees C, 0.5h). For in situ modification of their characteristics, either a self-generated atmosphere or flowing air was used. The activated carbons developed in the self-generated atmosphere showed higher BET surface area (2281m2/g) and total pore volume (1.7cm3/g) than those obtained under flowing air (1638m2/g and 1.3cm3/g). Conversely, the latter possessed a higher total amount of surface acidic/polar oxygen groups (2.2meq/g) than the former (1.5meq/g). To evaluate their metal sorption capability, adsorption isotherms of Cu(II) ion from model solutions were determined and properly described by the Langmuir model. Maximum sorption capacity (Xm) for the air-derived carbons (Xm=0.44mmol/g) almost duplicated the value for those obtained in the self-generated atmosphere (Xm=0.24mmol/g), pointing to a predominant effect of the surface functionalities on metal sequestering behaviour. The air-derived carbons also demonstrated a superior effectiveness in removing Cd(II) ions as determined from additional assays in equilibrium conditions. Accordingly, effective phosphoric acid-activated carbons from Prosopis wood for toxic metals removal from wastewater may be developed by in situ modification of their characteristics operating under flowing air.

Self-assembly from milli- to nanoscales: methods and applications.

The design and fabrication techniques for microelectromechanical systems (MEMS) and nanodevices are progressing rapidly. However, due to material and process flow incompatibilities in the fabrication of sensors, actuators and electronic circuitry, a final packaging step is often necessary to integrate all components of a heterogeneous microsystem on a common substrate. Robotic pick-and-place, although accurate and reliable at larger scales, is a serial process that downscales unfavorably due to stiction problems, fragility and sheer number of components. Self-assembly, on the other hand, is parallel and can be used for device sizes ranging from millimeters to nanometers. In this review, the state-of-the-art in methods and applications for self-assembly is reviewed. Methods for assembling three-dimensional (3D) MEMS structures out of two-dimensional (2D) ones are described. The use of capillary forces for folding 2D plates into 3D structures, as well as assembling parts onto a common substrate or aggregating parts to each other into 2D or 3D structures, is discussed. Shape matching and guided assembly by magnetic forces and electric fields are also reviewed. Finally, colloidal self-assembly and DNA-based self-assembly, mainly used at the nanoscale, are surveyed, and aspects of theoretical modeling of stochastic assembly processes are discussed.

In vitro friction of stainless steel arch wire-bracket combinations in air and different aqueous solutions.

OBJECTIVES: To investigate the in vitro coefficient of friction of stainless steel arch wire-bracket combinations under fretting contact test conditions performed in air and in different aqueous solutions, like Ringer solution, Ringer with addition of a buffer, Ringer with addition of glucose, and Coca Cola. METHODS: The fretting test set-up used allowed to control on-line the contact configuration and the positioning of the contacting parts. A specific positioning method was used to achieve a parallel alignment of arch wire and bracket slot. The effect of arch wire size, roughness, and test environment were investigated. RESULTS: It was found that the aqueous solutions act as a lubricant compared to air. Friction was affected by the arch wire width while the roughness was found to have a limited effect. Stainless steel 0.018'' x 0.025'' arch wires exhibited higher frictional forces than stainless steel 0.017'' x 0.025'' arch wires on sliding against stainless steel 0.018'' x 0.025'' brackets in the selected test environments when tested under identical fretting test conditions. The wear damage on the arch wire after these in-vitro fretting tests was investigated. It revealed that these in-vitro tests are governed by a competition between oxidational wear and abrasive wear taking place at contact areas between brackets and arch wires. CONCLUSIONS: For all aqueous solutions a lower coefficient of friction was found compared to tests performed in ambient air.

Dynamic frictional behaviour of orthodontic archwires and brackets.

The aim of this study was to evaluate the frictional behaviour of 15 different archwires and 16 different brackets using small oscillating displacements when opposed to a standard stainless steel bracket or a standard stainless steel wire. Tests were run according to a pilot study at a frequency of 1 Hz and with a reciprocating tangential displacement of 200 microm, while the wire remained centred in the bracket slot under a load of 2 N. The results indicated a significant difference between the evaluated wires and brackets. The mean coefficient of friction (COF) of the wires varied from 0.16 for Imagination NiTi tooth-coloured wire to 0.69 for the True Chrome Resilient Purple wire, while for the brackets it ranged from 0.39 for Ultratrimm to 0.72 for the Master Series. The fact that in this study, a large number of different commercially available archwires and brackets were evaluated with the same apparatus according to the same protocol, allows a direct comparison of the different archwire and bracket combinations, and can assist in the choice of the optimal bracket-wire combination with regard to friction.

Diagnóstico de la enfermedad carotídea arterioesclerotica / Diagnosis of carotid disease

Objetivos: (1) diseñar y evaluar una técnica de angiorresonancia 3D contrastada (ARM 3D) para el diagnóstico de la estenosis carotídea y compararla con la ecografía triplex (eco triplex) y la arteriografía por sustracción digital (ASD), esta última como estándar de referencia. (2) Evaluar la factibilidad de adicionar a la técnica anterior secuencias anatómicas y angiográficas del cerebro. Materiales y métodos: en 39 pacientes (78 carótidas) se estudió la bifurcación carotídea con ASD, angiorresonancia 3D con doble inyección y eco triplex. Se utilizó el método descrito en el estudio NASCET para cuantificar el grado de estenosis. Cada examen fue evaluado por observadores diferentes que no conocían el resultado de los otros métodos. Adicionalmente, se obtuvieron imágenes del cerebro y se describieron dichos hallazgos. Resultados: la angiorresonancia 3D con técnica de doble inyección detectó el 98 por ciento del grupo de carótidas clasificadas como normal-leves, el 83 por ciento de las estenosis moderadas, el 88 por ciento de las estenosis graves y el 100 por ciento de las oclusiones. Adicionalmente, dos errores diagnósticos (oclusiones falsas) de la ASD fueron identificados efectivamente por la ARM 3D. La eco triplex detectó el 92 por ciento del grupo normal-leve, el 33 por ciento de las estenosis moderadas, el 86 por ciento de las graves y todas las oclusiones encontradas con la ASD, pero la ecografía sobrestimó una estenosis leve a oclusión (falsa oclusión). La correlación estadística entre el estándar de referencia ASD y la ARM 3D fue buena a excelente, para los diferentes grados de estenosis (K>0,7 y K>0,9, respectivamente). En todos los pacientes se logró una evaluación adecuada del cerebro con resonancia. Conclusión: esta investigación sugiere que la ARM 3D con técnica de doble inyección tiene el potencial para remplazar la ASD en el diagnóstico y seguimiento de la enfermedad carotídea