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1.
Artículo en Inglés | MEDLINE | ID: mdl-38936970

RESUMEN

INTRODUCTION: Chemotherapy-induced peripheral neuropathy (CIPN) affects patients' quality of life and treatment effectiveness. Gabapentinoids, like gabapentin and pregabalin, are often used for CIPN treatment, but their efficacy and safety remain uncertain. This study reviews and analyses randomised controlled trial data on this topic. MATERIALS/METHODS: We searched PubMed, Embase and Cochrane CENTRAL until 29 August 2022 for studies on gabapentinoid use in CIPN. Meta-analysis was performed using RevMan V.5.4 and the Metafor package in R. Outcomes included pain scores, quality of life and adverse drug events. RESULTS: For the prevention setting, our meta-analysis shows that pregabalin did not significantly improve average pain (standardised mean difference (SMD) -0.14, 95% CI -0.51 to 0.23; I2=26% (95% CI 0% to >98%)) or quality of life (mean difference (MD) 2.5, 95% CI -4.67 to 9.67; p=0.49) in preventing CIPN compared with placebo. However, it showed a potential trend towards reducing the worst pain (SMD -0.28, 95% CI -0.57 to 0.01; I2=0% (95% CI 0% to 98%; p=0.06)). For the treatment setting, some studies have shown a potential therapeutic effect of gabapentinoids. However, the results are not consistent between studies. Given the studies' heterogeneity, a meta-analysis in treatment setting was not performed. CONCLUSION: There is limited evidence to support the use of gabapentinoids in CIPN. In prevention setting, gabapentinoids do not significantly prevent CIPN. In treatment setting, studies have been inconsistent in their conclusions, lacking definitive benefits over placebo. More comprehensive and higher quality research is needed in the future. PROSPERO REGISTRATION NUMBER: CRD42022361193.

2.
Materials (Basel) ; 17(12)2024 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-38930368

RESUMEN

Stainless steel grade 430 is a type of soft magnetic electromagnetic material with rapid magnetization and demagnetization properties. Considering the delay phenomenon during operation, this study selected 430 stainless steel as the material and explored various metallurgical methods such as magnetic annealing and the addition of Mo as well as increasing the Si content to investigate the microstructure, mechanical behavior, and magnetic properties of each material, aiming to improve the magnetic properties of 430 stainless steel. Experimental results showed that the four electromagnetic steel materials (430F, 430F-MA, 434, and KM31) had equiaxed grain matrix structures, and excellent tensile and elongation properties were observed for each specimen. Additionally, the magnetic properties of the 430F specimen were similar under the DC and AC-10 Hz conditions. According to the hysteresis curves under different AC frequencies (10, 100, 1000 Hz), both magnetic annealing and the addition of Mo could reduce the Bm, Br, and Hc values of the raw 430F material. Increasing the Si content resulted in a decrease in Hc values and an increase in Bm and Br values.

3.
Materials (Basel) ; 16(5)2023 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-36903177

RESUMEN

Surface roughness quality is still a significant problem in the laser powder bed fusion (LPBF) process. This study proposes a wobble-based scanning strategy to improve the insufficiencies of the traditional scanning strategy with regard to surface roughness. A laboratory LPBF system with a self-developed controller was used to fabricate Permalloy (Fe-79Ni-4Mo) with two scanning methods: traditional line scanning (LS) and the proposed wobble-based scanning (WBS). This study investigates the influences of these two scanning strategies on porosity and surface roughness. The results imply that WBS can maintain higher surface accuracy than LS, and the surface roughness can be reduced by about 45%. Furthermore, WBS can produce periodic surface structures arranged in fish scales or parallelograms with appropriate parameters.

4.
Materials (Basel) ; 15(16)2022 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-36013797

RESUMEN

Due to its advantages of high customization and rapid production, metal laser melting manufacturing (MAM) has been widely applied in the medical industry, manufacturing, aerospace and boutique industries in recent years. However, defects during the selective laser melting (SLM) manufacturing process can result from thermal stress or hardware failure during the selective laser melting (SLM) manufacturing process. To improve the product's quality, the use of defect detection during manufacturing is necessary. This study uses the process images recorded by powder bed fusion equipment to develop a detection method, which is based on the convolutional neural network. This uses three powder-spreading defect types: powder uneven, powder uncovered and recoater scratches. This study uses a two-stage convolutional neural network (CNN) model to finish the detection and segmentation of defects. The first stage uses the EfficientNet B7 to classify the images with/without defects, and then to locate the defects by evaluating three different instance segmentation networks in second stage. Experimental results show that the accuracy and Dice measurement of Mask-R-CNN network with ResNet 152 backbone can reach 0.9272 and 0.9438. The computational time of an image only takes approximately 0.2197 sec. The used CNN model meets the requirements of the early detected defects, regarding the SLM manufacturing process.

5.
J Nanosci Nanotechnol ; 17(1): 773-79, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29634163

RESUMEN

As-deposited CuInSe2 thin films by electrodeposition method are usually accompanied with amorphous structure which is regarded detrimental for solar cell conversion efficiency. In this work, we proposed an annealing method under high pressure for improving the conversion efficiency of electrodeposited CuInSe2 thin film solar cells, and the microstructure of high-pressure annealed CuInSe2 films were also investigated. The annealing pressure was set from 100 kPa to 250 kPa, and the annealed CuInSe2 thin films were then fabricated into solar cell using standard process. Field-emission scanning electron microscopy (FESEM) images show that CuInSe2 films with higher annealing pressure demonstrate denser and smoother surface morphology. Results from X-ray diffraction (XRD) and Raman spectra indicate that annealing under high pressure enhanced the (1 1 2) preferential orientation of CuInSe2 films and also eliminated binary Cu­Se phases. Finally, through annealing CuInSe2 absorber layer under 200 kPa, the fill factor of the CuInSe2 solar cell was found to be improved from 28.4% to 55% and the efficiency from 2.77% to 6.91%.

6.
Nanoscale Res Lett ; 9(1): 660, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25593551

RESUMEN

Photo-assisted one-step electrodeposition has been applied to help in forming smooth and dense CuInSe2 films. The difference in surface morphology and crystalline quality between CuInSe2 films with various photo-assistance has been investigated. In the photo-assisted electrodeposition process, the many kinds of lamps providing maximum light intensity at about 380 to 620 nm were used as light source to be irradiated onto the surface of Mo-coated soda-lime glass substrates. The results suggested effects of photo-assistance including activating surface diffusion and growing high-crystalline quality films with reduced defects during electrodeposition.

7.
Int J Nanomedicine ; 7: 4409-18, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22923986

RESUMEN

To resolve problems of long treatment durations and frequent administration of the antifungal agent terbinafine (TB), solid lipid nanoparticles (SLNs) with the ability to load lipophilic drugs and nanosize were developed. The SLNs were manufactured by a microemulsion technique in which glyceryl monostearate (GMS), glyceryl behenate (Compritol(®) 888; Gattefossé), and glyceryl palmitostearate (Precirol(®) ATO 5; Gattefossé) were used as the solid lipid phases, Tween(®) and Cremophor(®) series as the surfactants, and propylene glycol as the cosurfactant to construct ternary phase diagrams. The skin of nude mice was used as a barrier membrane, and penetration levels of TB of the designed formulations and a commercial product, Lamisil(®) Once™ (Novartis Pharmaceuticals), in the stratum corneum (SC), viable epidermis, and dermis were measured; particle sizes were determined as an indicator of stability. The optimal SLN system contained a <5% lipid phase and >50% water phase. The addition of ethanol or etchants had no significant effect on enhancing the amount of TB that penetrated the skin layers, but it was enhanced by increasing the percentage of the lipid phase. Furthermore, the combination of GMS and Compritol(®) 888 was able to increase the stable amount of TB that penetrated all skin layers. For the ACP1-GM1 (4% lipid phase; Compritol(®) 888: GMS of 1:1) formulation, the amount of TB that penetrated the SC was similar to that of Lamisil(®) Once™, whereas the amount of TB of the dermis was higher than that of Lamisil(®) Once™ at 12 hours, and it was almost the same as that of Lamisil(®) Once™ at 24 hours. It was concluded that the application of ACP1-GM1 for 12 hours might have an efficacy comparable to that of Lamisil(®) Once™ for 24 hours, which would resolve the practical problem of the longer administration period that is necessary for Lamisil(®) Once™.


Asunto(s)
Nanopartículas/administración & dosificación , Nanopartículas/química , Naftalenos/administración & dosificación , Naftalenos/química , Administración Cutánea , Animales , Antifúngicos/administración & dosificación , Antifúngicos/química , Antifúngicos/farmacocinética , Dermis/química , Dermis/metabolismo , Formas de Dosificación , Portadores de Fármacos/administración & dosificación , Portadores de Fármacos/química , Epidermis/química , Epidermis/metabolismo , Glicéridos/administración & dosificación , Glicéridos/química , Cinética , Ratones , Ratones Desnudos , Microscopía Electrónica de Rastreo , Naftalenos/farmacocinética , Tamaño de la Partícula , Absorción Cutánea , Solubilidad , Terbinafina
8.
Med Eng Phys ; 34(4): 498-505, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-21925921

RESUMEN

Failure of ultra-high molecular weight polyethylene components after total disc replacements in the lumbar spine has been reported in several retrieval studies, but immediate biomechanical evidence for those mechanical failures remained unclear. Current study aimed to investigate the failure mechanisms of commercial lumbar disc prostheses and to enhance the biomechanical performances of polyethylene components by modifying the articulating surface into a convex geometry. Modified compressive-shearing tests were utilized in finite element analyses for comparing the contact, tensile, and shearing stresses on two commercial disc prostheses and on a concave polyethylene design. The influence of radial clearance on stress distributions and prosthetic stability were considered. The modified compressive-shearing test revealed the possible mechanisms for transverse and radial cracks of polyethylene components, and would be helpful in observing the mechanical risks in the early design stage. Additionally, the concave polyethylene component exhibited lower contact and shearing stresses and more acceptable implant stability when compared with the convex polyethylene design through all radial clearances. Use of a concave polyethylene component in lumbar disc replacements decreased the risk of transverse and radial cracks, and also helped to maintain adequate stability. This design concept should be considered in lumbar disc implant designs in the future.


Asunto(s)
Materiales Biocompatibles , Fuerza Compresiva , Análisis de Elementos Finitos , Vértebras Lumbares/cirugía , Polietileno , Resistencia al Corte , Reeemplazo Total de Disco , Fenómenos Biomecánicos , Ensayo de Materiales , Estrés Mecánico , Propiedades de Superficie , Resistencia a la Tracción
9.
Knee Surg Sports Traumatol Arthrosc ; 20(9): 1730-5, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22048749

RESUMEN

PURPOSE: The objective of this study was to analyze the morphology of the medial tibial plateau and lateral tibial plateau in Chinese knees and compared these measurements and features with those of commercial unicondylar tibial baseplates. METHODS: Three-dimensional knee models were reconstructed from computed tomography slices of 81 subjects. Among the series, 27 knees were from male subjects and 54 knees from female subjects. The dimensions and shape of the medial and lateral tibial plateaus were measured and compared with six commercially available unicondylar tibial baseplates. RESULTS: The results showed significant differences between the shapes of the medial and lateral tibial plateaus. For the lateral tibial plateau, the shape was symmetric about the mediolateral axis. The medial plateaus presented their widest mediolateral width in an obviously more posterior position than the lateral compartment. Additionally, the plateau aspect ratio decreased with increasing mediolateral dimensions, in contrast to the constant aspect ratio shown by conventional unicondylar knee prostheses. CONCLUSION: Compartment-specific designs may optimize coverage between the prosthesis and resected tibial surface. The morphometrical measurements presented may allow manufacturers to design tibial baseplates that accommodate the structural variability between different ethnic groups. LEVEL OF EVIDENCE: Prospective comparative study, Level II.


Asunto(s)
Articulación de la Rodilla/diagnóstico por imagen , Prótesis de la Rodilla , Tibia/diagnóstico por imagen , Adulto , Anciano , Pueblo Asiatico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos Anatómicos , Diseño de Prótesis , Tomografía Computarizada por Rayos X
10.
Med Eng Phys ; 33(10): 1175-82, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21741289

RESUMEN

Persistent pain and periprosthetic fracture of the proximal tibia are troublesome complications in modern unicondylar knee arthroplasty (UKA). Surgical errors and acute corners on the resected surface can place excessive strains on the bone, leading to bone degeneration. This study attempted to lower strains by altering the orthogonal geometry and avoiding extended vertical saw cuts. Finite element models were utilized to predict biomechanical behavior and were subsequently compared against experimental data. On the resected surface of the extended saw cut model, the greatest strains showed a 50% increase over a standard implant; conversely, the strains decreased by 40% for the radial-corner shaped model. For all UKA models, the peak strains below the resection level increased by 40% relative to an intact tibia. There was no significant difference among the implanted models. This study demonstrated that a large increase in strains arises on the tibial plateau to resist a cantilever-like bending moment following UKA. Surgical errors generally weaken the tibial support and increase the risk of fractures. This study provides guidance on altering the orthogonal geometry into a radial-shape to reduce strains and avoid degenerative remodeling. Furthermore, it could be expected that predrilling a posteriorly sloped tunnel through the tibia prior to cutting could achieve greater accuracy in surgical preparations.


Asunto(s)
Artroplastia de Reemplazo de Rodilla/métodos , Análisis de Elementos Finitos , Fenómenos Mecánicos , Tibia/cirugía , Fenómenos Biomecánicos , Errores Médicos , Modelos Anatómicos , Reproducibilidad de los Resultados , Estrés Mecánico , Resultado del Tratamiento
11.
Clin Biomech (Bristol, Avon) ; 26(8): 847-52, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21546143

RESUMEN

BACKGROUNDS: The post-cam design of contemporary posterior stabilized knee prosthesis can be categorized into flat-on-flat or curve-on-curve contact surfaces. The curve-on-curve design has been demonstrated its advantage of reducing stress concentration when the knee sustained an anteroposterior force with tibial rotation. How the post-cam design affects knee kinematics is still unknown, particularly, to compare the difference between the two design features. Analyzing knee kinematics of posterior stabilized knee prosthesis with various post-cam designs should provide certain instructions to the modification of prosthesis design. METHODS: A dynamic knee model was utilized to investigate tibiofemoral motion of various post-cam designs during high knee flexion. Two posterior stabilized knee models were constructed with flat-on-flat and curve-on-curve contact surfaces of post-cam. Dynamic data of axial tibial rotation and femoral translation were measured from full-extension to 135°. FINDINGS: Internal tibial rotation increased with knee flexion in both designs. Before post-cam engagement, the magnitude of internal tibial rotation was close in the two designs. However, tibial rotation angle decreased beyond femoral cam engaged with tibial post. The rate of reduction of tibial rotation was relatively lower in the curve-on-curve design. From post-cam engagement to extreme flexion, the curve-on-curve design had greater internal tibial rotation. INTERPRETATION: Motion constraint was generated by medial impingement of femoral cam on tibial post. It would interfere with the axial motion of the femur relative to the tibia, resulting in decrease of internal tibial rotation. Elimination of rotational constraint should be necessary for achieving better tibial rotation during high knee flexion.


Asunto(s)
Fémur/anatomía & histología , Prótesis de la Rodilla , Diseño de Prótesis/métodos , Tibia/anatomía & histología , Artroplastia de Reemplazo de Rodilla/métodos , Fenómenos Biomecánicos , Humanos , Rodilla/anatomía & histología , Articulación de la Rodilla/cirugía , Modelos Estadísticos , Movimiento (Física) , Movimiento , Rango del Movimiento Articular , Rotación
12.
Clin Biomech (Bristol, Avon) ; 26(6): 612-9, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21377253

RESUMEN

BACKGROUNDS: Deficiencies in contemporary posterior crucitate retaining knee included inadequate femoral rollback and insufficient tibial rotation. Current study attempted to restore normal femoral rollback and tibial rotation to facilitate in knee flexion/extension and to achieve appropriate posture at deep knee bending after total knee arthroplasy by mimicking the morphology of convexly lateral tibial plateau of intact knee. METHODS: Computational simulation was utilized to analyze motion of three-dimensional knee models, including intact, traditionally symmetrical posterior crucitate retaining and newly anatomic-like posterior crucitate retaining knees. Solid bones, attachments of ligaments and tendons of simulation models were reconstructed by magnetic resonance images of the subject. According to the representative literature, the distal femur was modeled to rotate about the specific axes and the motion of the proximal tibial was unconstrained except for the flexion/extension. Movements of the medial/lateral condyles and tibial rotation were recorded and analyzed. FINDINGS: The newly anatomic-like posterior crucitate retaining knee improved the posterior movement of lateral condyle and tibial internal rotation significantly during full range of flexion. Compared with traditionally symmetrical posterior crucitate retaining knee, the improvements displayed by newly developed posterior crucitate retaining knee in posterior movement of lateral condyle and tibial internal rotation were 11.2mm and 9.3° at full flexion, respectively. INTERPRETATION: The newly anatomic-like posterior crucitate retaining knee demonstrated that mimicking the morphology of convexly lateral tibial plateau can be expected to restore normal knee kinematics.


Asunto(s)
Artroplastia de Reemplazo de Rodilla/métodos , Articulación de la Rodilla/cirugía , Polietileno/química , Adulto , Fenómenos Biomecánicos , Simulación por Computador , Femenino , Humanos , Rodilla/fisiología , Modelos Anatómicos , Postura , Programas Informáticos , Tibia/patología
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