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1.
Foot Ankle Orthop ; 4(4): 2473011419890861, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35097353

RESUMEN

BACKGROUND: Isolated distal fibular fractures resulting from supination external rotation (SER) injuries without evidence of obvious talar shift on standard radiographs present a diagnostic dilemma for clinicians. The status of the deep deltoid ligament, the main stabilizer of the ankle joint, is assessed by an increase in medial clear space (MCS) on radiographs. Therefore, these injuries can be either stable or unstable. In recent years, considerable clinical and research efforts have been made to determine ankle stability following SER fracture. The purpose of this systematic review was to evaluate and compare the role of different stress radiograph modalities in assessing stability of the ankle with SER fractures with no obvious talar subluxation on standard radiographs. METHODS: The electronic databases MEDLINE, EMBASE, Ovid, Cochrane Central, CINAHL, and Google Scholar were searched from January 2000 to January 2018 to identify literature relating to radiologic assessment of stability of SER ankle fractures. RESULTS: Our literature search revealed 10 peer-reviewed articles that fulfilled inclusion criteria. This yielded a total of 698 patients. The systematic review found 3 broad categories of radiographic investigations in the assessment of ankle joint stability: external rotation (ER) stress radiographs, gravity stress views (GSV), and weightbearing (WB) radiographs. Proponents of WB radiographs have demonstrated how axial load can normalize ankle joint alignment in cases of proven instability. There was a consistently high grade of evidence for using a medial clear space (MCS) value of more than 4 to 5 mm to indicate an unstable ankle following SER fracture. CONCLUSION: In conclusion, the results of this systematic review support an MCS value of less than 4 to 5 mm as a good indicator of stability, regardless of choice of stress imaging modality. These patients can be allowed early weightbearing with expected good functional outcomes. Recent published literature favors WB stress radiographs as a reliable and safe technique for assessing stability in SER ankle fractures. However, it should be kept in mind that this is based on studies with relatively low grades of evidence. LEVEL OF EVIDENCE: Level II, systematic review of variable quality studies.

2.
J Am Podiatr Med Assoc ; 104(5): 518-21, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25275742

RESUMEN

Stress fractures commonly occur in athletes and military cadets due to repetitive stress on the bony cortex. Stress fractures of the tibia are commonly localized proximally and occur during aerobic weightbearing exercises. This is an unusual case of bilateral simultaneous distal tibial stress fracture in a young homemaker.


Asunto(s)
Fracturas por Estrés/diagnóstico , Tibia/lesiones , Adulto , Enfermedades Óseas Metabólicas/diagnóstico , Dieta Vegetariana , Femenino , Humanos , Conducta Sedentaria , Tibia/diagnóstico por imagen , Deficiencia de Vitamina D/diagnóstico
3.
Sci Rep ; 3: 2257, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23877112

RESUMEN

Chemically modified single-walled carbon nanotubes (SWNTs) with varying degrees of functionalization were utilized for the fabrication of SWNT thin film catalyst support layers (CSLs) in polymer electrolyte membrane fuel cells (PEMFCs), which were suitable for benchmarking against the US DOE 2017 targets. Use of the optimum level of SWNT -COOH functionality allowed the construction of a prototype SWNT-based PEMFC with total Pt loading of 0.06 mg(Pt)/cm²--well below the value of 0.125 mg(Pt)/cm² set as the US DOE 2017 technical target for total Pt group metals (PGM) loading. This prototype PEMFC also approaches the technical target for the total Pt content per kW of power (<0.125 g(PGM)/kW) at cell potential 0.65 V: a value of 0.15 g(Pt)/kW was achieved at 80°C/22 psig testing conditions, which was further reduced to 0.12 g(Pt)/kW at 35 psig back pressure.


Asunto(s)
Fuentes de Energía Bioeléctrica , Nanotubos de Carbono/química , Catálisis , Electroquímica , Electrodos , Ensayo de Materiales , Nanotubos de Carbono/ultraestructura
5.
Foot Ankle Int ; 34(8): 1064-7, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23669161

RESUMEN

BACKGROUND: Although many treatment modalities are available for Morton's neuroma (MN), studies looking at the long-term effectiveness of most forms of treatment are scarce. The injection of MN with alcohol has gained popularity over the past 10 years with widespread media coverage. Many surgeons have anecdotally questioned the long-term effectiveness of this treatment. We reviewed a cohort of patients at an average 5-year follow-up to assess the medium-term results of alcohol injection. METHODS: We used the modified Johnson score and visual analogue scales to assess 45 of the original cohort of patients with an average follow-up of 61 months (range, 33-73 months). Any complications from the procedure were also noted. RESULTS: Our results indicated that by 5 years, 16 of 45 patients had undergone surgical treatment and a further 13 patients had return of symptoms. Only 29% (13/45) remained symptom free. The visual analog scale and modified Johnson scores showed statistically significant deterioration in patients' symptoms at 5 years following alcohol injection. CONCLUSION: Injection with alcohol sclerosant for MN has been marketed as a definitive management option comparable to surgical excision. Our investigation illustrated that although short-term results are encouraging, alcohol injection does not offer permanent resolution of symptoms for most patients and can be associated with considerable morbidity. Our investigation provides the only long-term data for alcohol injection treatment of MN. LEVEL OF EVIDENCE: Level II, prospective case series.


Asunto(s)
Alcoholes/administración & dosificación , Neuroma/tratamiento farmacológico , Soluciones Esclerosantes/administración & dosificación , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Humanos , Inyecciones Intraarticulares , Masculino , Persona de Mediana Edad , Neuroma/diagnóstico por imagen , Neuroma/cirugía , Estadísticas no Paramétricas , Resultado del Tratamiento , Ultrasonografía
6.
J Foot Ankle Surg ; 52(3): 367-9, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23376005

RESUMEN

Transcalcaneal talonavicular dislocation is a rare injury, with very few reported cases. Of these, most have been the result of high-energy mechanisms such as road traffic collisions or falls from a height. The management of this injury is challenging, and treatment is fraught with a high rate of disability, infection, and amputation. We describe the successful management of the first reported case of a low-energy transcalcaneal talonavicular dislocation in a 71-year-old female. Combined external and internal fixation was used to reduce and maintain the injury, with a resultant good functional and complication-free outcome at 1 year after the injury. Our experience highlights the prevalence of these devastating injuries caused by relatively benign mechanisms in an increasingly older population with osteoporotic bone. It also indicates that operative stabilization of a low-energy injury can be more successful than that with the traditional high-velocity trauma.


Asunto(s)
Articulaciones del Pie/lesiones , Articulaciones del Pie/cirugía , Luxaciones Articulares/cirugía , Anciano , Femenino , Articulaciones del Pie/diagnóstico por imagen , Fijación de Fractura , Humanos , Luxaciones Articulares/diagnóstico por imagen , Radiografía
7.
Foot Ankle Spec ; 5(5): 330-3, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22965219

RESUMEN

The authors present a case of an incidental finding of a metallic foreign body located within the calcaneus of a 17-year-old girl. Although the presence of foreign material is a common occurrence in the foot, intraosseous metallic bodies are rare, especially so when they present as an incidental finding. A literature review of PubMed using keywords metallic, foreign body, and calcaneus revealed only a single case report, which did not present as an incidental finding. The presentation described here is rare and provides a platform for discussion about possible management options.


Asunto(s)
Calcáneo/diagnóstico por imagen , Cuerpos Extraños/diagnóstico por imagen , Hallazgos Incidentales , Metales , Adolescente , Traumatismos del Tobillo/complicaciones , Servicio de Urgencia en Hospital , Femenino , Humanos , Esguinces y Distensiones/complicaciones , Tomografía Computarizada por Rayos X
9.
Foot Ankle Spec ; 4(3): 171-4, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21368066

RESUMEN

The authors present a previously unreported case of an open fracture of the distal tibia and fibula with associated Achilles tendon rupture in a 27-year-old motorcyclist. Management followed established trauma principles of wound exploration, debridement, and stabilization of the fracture with reamed locked intramedullary nailing of the tibia. The injury to the Achilles tendon was not identified until surgical exploration for fixation of the fracture. This required a 2-stage operative approach, involving initial debridement and fracture fixation followed by Achilles tendon repair during the second-look wound review procedure. The authors believe this to be the first reported case of Achilles tendon rupture in association with an open transverse distal tibia fracture. Prior to surgical exploration of the wound, Achilles tendon rupture was not suspected, emphasizing the need for clinical suspicion, thorough examination, and adequate wound exploration at operation for fracture fixation.


Asunto(s)
Tendón Calcáneo/lesiones , Peroné/lesiones , Fracturas Abiertas/complicaciones , Fracturas de la Tibia/complicaciones , Accidentes de Tránsito , Tendón Calcáneo/cirugía , Adulto , Fijación Intramedular de Fracturas , Fracturas Abiertas/cirugía , Humanos , Masculino , Motocicletas , Rotura , Fracturas de la Tibia/cirugía
10.
J Am Chem Soc ; 132(41): 14429-36, 2010 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-20873843

RESUMEN

We report the effect of electrochemical oxidation in nitric acid on the electronic properties of epitaxial graphene (EG) grown on silicon carbide substrates; we demonstrate the availability of an additional reaction channel in EG, which is not present in graphite but which facilitates the introduction of the reaction medium into the graphene galleries during electro-oxidation. The device performance of the chemically processed graphene was studied by patterning the EG wafers with two geometrically identical macroscopic channels; the electro-oxidized channel showed a logarithmic increase of resistance with decreasing temperature, which is ascribed to the scattering of charge carriers in a two-dimensional electronic gas, rather than the presence of an energy gap at the Fermi level. Field-effect transistors were fabricated on the electro-oxidized and pristine graphene channels using single-walled carbon nanotube thin film top gate electrodes, thereby allowing the study of the effect of oxidative chemistry on the transistor performance of EG. The electro-oxidized channel showed higher values for the on-off ratio and the mobility of the graphene field-effect transistor, which we ascribe to the availability of high-quality internal graphene layers after electro-oxidation of the more defective top layers. Thus, the present oxidative process provides a clear contrast with previously demonstrated covalent chemistry in which sp(3) hybridized carbon atoms are introduced into the graphitic transport layer of the lattice by carbon-carbon bond formation, thereby opening an energy gap.

11.
J Phys Condens Matter ; 22(33): 334216, 2010 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-21386506

RESUMEN

We report the thermal conductivities of graphite nanoplatelet-epoxy composites prepared by exfoliation of natural graphite flakes of varying lateral sizes. We found that utilization of natural graphite flakes of the optimum lateral dimensions (∼200-400 µm) as a starting material for exfoliation significantly enhanced the thermal conductivity of the composite. In order to understand this enhancement we developed a procedure for evaluation of the particle size distribution of graphite nanoplatelets and correlated the measured distributions with the resulting thermal conductivities. In order to expand the scope of our study we applied our statistical and thermal analysis to commercially available graphite nanoplatelet materials.


Asunto(s)
Grafito/química , Modelos Químicos , Nanoestructuras/química , Nanoestructuras/ultraestructura , Simulación por Computador , Sustancias Macromoleculares/química , Ensayo de Materiales , Conformación Molecular , Tamaño de la Partícula , Propiedades de Superficie , Temperatura , Conductividad Térmica
12.
J Am Chem Soc ; 131(4): 1336-7, 2009 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-19173656

RESUMEN

The addition of nitrophenyl groups to the surface of few-layer epitaxial graphene (EG) by the formation of covalent carbon-carbon bonds changed the electronic structure and transport properties of the EG from near-metallic to semiconducting.

13.
J Phys Chem B ; 110(49): 24816-21, 2006 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-17149899

RESUMEN

Photoluminescence (PL) from purified (>90%) double-wall carbon nanotubes (DWNTs), which have been synthesized by zeolite catalyst-supported chemical vapor deposition (zeolite-CCVD), of very small diameters (0.8-nm average inner tube) is reported. The PL contour mappings for various ratios (1-90%) of double- versus single-wall carbon nanotubes by thermal oxidation have enabled us to unambiguously identify the chirality of inner tubes for the DWNTs synthesized. After the extensive high-temperature oxidation at 700 degrees C, high-purity (>90%) DWNTs of approximately 0.8 nm inner diameter are obtained, and most of these correspond to the DWNTs having inner tubes with chiralities of (7,5), (7,6), and (9,4).

14.
J Phys Chem B ; 110(1): 130-5, 2006 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-16471510

RESUMEN

High-quality single-wall carbon nanotubes (SWNTs) with narrow diameter distribution have been grown on Fe/Co-loaded MCM41 by using acetylene as the carbon source within a short reaction period, typically 10 min or less. The optimum temperature for SWNTs synthesis is 850 degrees C. Longer reaction time (i.e., 30 min) favors the formation of multiwall carbon nanotubes (MWNTs) and graphitic carbon. When the reaction time is reduced to less than 10 min, formation of MWNTs and graphitic carbon is greatly suppressed, and high-quality SWNTs dominates the yield. The surface of the as-grown SWNTs is found to be free from amorphous carbon, as observed from high-resolution transmission electron microscope (HRTEM) analysis. Raman spectral data show a G/D ratio above 10, indicating that the as-grown SWNTs have very few defects. Furthermore, radial breathing mode (RBM) analysis reveals that the diameter distribution of the current SWNTs is narrow and ranges from 0.64 to 1.36 nm.

15.
J Phys Chem B ; 109(3): 1141-7, 2005 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-16851073

RESUMEN

Double-wall carbon nanotubes (DWNTs) have been selectively synthesized over Fe/Co loaded mesoporous silica by catalytic chemical vapor deposition of alcohol. Several silica materials with desired pore diameter and morphology have been investigated for the DWNT growth. The diameter distribution and selectivity of the DWNT are found to depend on the reaction temperature, pore size, and thermal stability of the support material. A high-yield synthesis of DWNTs has been achieved at 900 degrees C over high-temperature stable mesoporous silica. The outer diameter of DWNTs is found to be in the range of 1.5-5.4 nm with a "d" spacing of 0.38 +/- 0.02 nm between inner and outer layers, which is much larger than those of multiwall carbon nanotubes.


Asunto(s)
Nanotubos de Carbono/química , Dióxido de Silicio/química , Alcoholes/química , Catálisis , Cobalto/química , Calor , Hierro/química , Microscopía Electrónica de Rastreo/métodos , Microscopía Electrónica de Transmisión/métodos , Tamaño de la Partícula , Porosidad , Estándares de Referencia , Sensibilidad y Especificidad , Espectrometría Raman/métodos , Espectrometría Raman/normas , Propiedades de Superficie , Volatilización , Difracción de Rayos X
16.
Knee ; 11(2): 141-2, 2004 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15066628

RESUMEN

A case of inferior dislocation of the patella in an 80-year-old woman with an osteo-arthritic knee is presented. This is a rare injury in the degenerate knee and the first case in which recurrence, the need for operative reduction and intra-articular damage has been demonstrated.


Asunto(s)
Osteoartritis de la Rodilla/complicaciones , Luxación de la Rótula/etiología , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Rótula/lesiones , Luxación de la Rótula/cirugía , Recurrencia
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