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1.
BMC Musculoskelet Disord ; 24(1): 134, 2023 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-36803129

RESUMO

BACKGROUND: This study compared the re-revision rate and radiographic outcomes of revision total hip arthroplasty (THA) using a Kerboull-type acetabular reinforcement device (KT plate) with bulk structural allograft and metal mesh with impaction bone grafting (IBG). METHODS: Ninety-one hips of 81 patients underwent revision THA for American Academy of Orthopedic Surgeons (AAOS) classification type III defects from 2008 to 2018. Of these, seven hips of five patients and 15 hips of 13 patients were excluded due to insufficient follow-up information (< 24 months) and large bone defects with a vertical defect height ≥ 60 mm, respectively. The current study compared the survival and radiographic parameters of 45 hips of 41 patients using a KT plate (KT group) and 24 hips of 24 patients using a metal mesh with IBG (mesh group). RESULTS: Eleven hips (24.4%) in the KT group and 1 hip (4.2%) in the mesh group exhibited radiological failure. Moreover, 8 hips in the KT group (17.0%) required a re-revision THA, while none of the patients in the mesh group required a re-revision. The survival rate with radiographic failure as the endpoint in the mesh group was significantly higher than that in the KT group (100% vs 86.7% at 1-year and 95.8% vs 80.0% at 5-years, respectively; p = 0.032). On multivariable analysis evaluating factors associated with radiographic failure, there were no significant associations with any radiographic measurement. Of the 11 hips with radiographic failure, 1 (11.1%), 3 (12.5%), and 7 (58.3%) hips were of Kawanabe classification stages 2, 3, and 4, respectively. CONCLUSIONS: The findings of this study suggest that revision THA using KT plates with bulk structure allografts could provide poorer clinical outcomes than revision THA using a metal mesh with IBG. Although revision THA using KT plates with bulk structural allografts could set the true hip center, there is no association between a high hip center and clinical outcomes. The relationship between the position of the KT plate and the host bone might be considered more carefully.


Assuntos
Artroplastia de Quadril , Prótese de Quadril , Humanos , Artroplastia de Quadril/efeitos adversos , Transplante Ósseo , Telas Cirúrgicas , Resultado do Tratamento , Falha de Prótese , Acetábulo/diagnóstico por imagem , Acetábulo/cirurgia , Reoperação , Metais , Seguimentos , Estudos Retrospectivos
2.
Int J Biometeorol ; 67(7): 1251-1261, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37256387

RESUMO

This study investigated the applicability of expanded metal meshes (EMMs) in horizontal shading devices. We performed simulations and experiments with EMMs with different opening ratios and directions. We established various experimental and control groups to measure air temperature, surface temperature, and black globe temperature. After the comparison of simulation and experimental data, we used Grasshopper to simulate long-term climate situations. The research results can serve as reference for users in Tainan and provide customized suggestions. The findings can serve as a paradigm for parametric design to analyze EMMs. In design projects involving outdoor horizontal shading devices, these results can be used in the design phase for evaluation. Full-day measurements revealed that EMMs with small openings exhibited favorable shading effects. In the Tainan area, we suggest using north-facing EMMs; in our simulations result, 70% of sunshine did not pass through the mesh in a day. For shading equipment in the morning, west-facing EMMs should be used because they blocked 50-90% of sunshine. For recreational areas in the afternoon and evening, east-facing EMMs can block 50-90% of sunshine after noon. In Taiwan, south-facing EMMs are not advised because their shading performance is suboptimal in the morning and afternoon.


Assuntos
Clima , Temperatura , Taiwan
3.
Sensors (Basel) ; 23(3)2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36772573

RESUMO

This study provides information on the transfer efficiency of four-plate-structured copper plate and metal mesh sheet couplers, the cause of null-power point. The couplers are compared based on the equivalent circuit model analysis, experimental results of fabricated couplers, and simulation results of the High-Frequency Structure Simulator (HFSS) tool. It was confirmed that the metal mesh material exhibits the same performance as the existing copper plate and can be fully used as a coupler material for the electrical resonance wireless power transfer system. In addition, the null-power point phenomenon is only determined by the main coupling and cross coupling between the transmitter and receiver, which are most dominantly affected by the coupler structure.

4.
Molecules ; 28(7)2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-37049874

RESUMO

Recently, semiconductor wastewater treatment has received much attention due to the emergence of environmental issues. Acid-resistant coatings are essential for metal prefilters used in semiconductor wastewater treatment. Perfluoroalkoxy alkane is mainly used as an acid-resistant coating agent, since PFA has inherent superhydrophobicity, water permeability is lowered. To solve this problem, the surface of the PFA-coated metal mesh was treated via an oxyfluorination method in which an injected mixed gas of fluorine and oxygen reacted with the surface functional groups. Surface analysis, water contact angle measurement, and water permeability tests were performed on the surface-treated PFA-coated mesh. Consequently, the superhydrophobic surface was effectively converted to a hydrophobic surface as the PFA coating layer was surface-modified with C-O-OH functional groups via the oxyfluorination reaction. As a result of using simulation solutions that float silica particles of various sizes, the permeability and particle removal rate of the surface-modified PFA-coated stainless-steel mesh were improved compared to those before surface modification. Therefore, the oxyfluorination treatment used in this study was suitable for improving the filtration performance of SiO2 microparticles in the PFA-coated stainless-steel mesh.

5.
Stomatologiia (Mosk) ; 100(4): 77-82, 2021.
Artigo em Russo | MEDLINE | ID: mdl-34357733

RESUMO

THE RELEVANCE OF THE STUDY: Is dictated by the insufficient strength of the bases of removable plate prostheses made of acrylic plastic masses. The literature data confirm the high prevalence of strips of removable plate prostheses made of acrylic plastics, regardless of the complexity of the clinical situation, but in great dependence on the time of use of prostheses. The search for new approaches to reduce the risks of structural failures, regardless of the operating time, led to the emergence of a metal mesh and a composite frame. THE PURPOSE OF THE WORK: Is a comparative analysis of the resistance of structures to moisture and heat, in accordance with GOST R 57695-2017, aimed at modeling the aging of samples from acrylic polymers reinforced with a metal mesh and a composite frame based on fiberglass. MATERIALS AND METHODS: The whole experiment was carried out in accordance with GOST R 57695-2017 and was aimed at modeling the aging of three types of samples of acrylic polymers and combinations: «acrylic polymer-metal mesh¼, «acrylic polymer-composite frame¼ of size 20×18×1, 8 mm for studying microstructure and morphology. The obtained profiles of samples with a simulated aging effect were evaluated using an Axiovert 40MT optical microscope (Carl Zeiss), with an increase of ×200, ×500. RESULTS: Analysis of the microstructure data showed that profiles of 3 types of samples before exposure to aging factors have a homogeneous structure with a rough surface. With an increase of ×500 in four samples with a metal mesh, both before and after exposure to moisture and heat, the presence of voids between the base material and the metal reinforcing component is noted. In samples reinforced with composite material, its pronounced integration with acrylic plastic is preserved, which is due to the presence of a chemical bond. During the experiment, it was found that the conditions modeled according to GOST R 57695-2017 do not significantly affect the structure of the samples, and the morphology analysis revealed a close fit between the components of the materials in the combined samples and the absence of changes at the interface. CONCLUSIONS: The proposed option of reinforcing the base of a removable laminar denture, due to the introduction of a skeleton made of composite material based on fiberglass, is optimal for increasing the effectiveness of orthopedic treatment.


Assuntos
Resinas Acrílicas , Bases de Dentadura , Humanos , Teste de Materiais , Plásticos , Polimetil Metacrilato
6.
BMC Musculoskelet Disord ; 20(1): 355, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31370807

RESUMO

BACKGROUND: Good outcomes have been reported in revision total hip replacement with massive segmental defects using impaction bone grafting with circumferential metal meshes. However, the morphology of defects that require a mesh is poorly defined. The purpose of this study was to evaluate the effects of a variety of segmental defects on load transmission to the proximal femur under both axial and rotational loads. METHODS: Initial stability of the Exeter stem was investigated in a composite bone model using three medial bone defect morphologies: Long (length 5 cm × width 2 cm), Short (2.5 cm × 2 cm), Square (3.2 cm × 3.2 cm), Square with mesh (3.2 cm × 3.2 cm defect covered with metal mesh), and with no defect as control. Specimens (5 per group) were axially loaded and internally rotated up to 20° or to failure. Strain distributions of the femora were measured using a strain gauge. RESULTS: All Square group specimens failed while rotation was increasing. In the other four groups, failure was not observed in any specimens. Mean torsional stiffness in the Long (4.4 ± 0.3 Nm/deg.) and Square groups (4.3 ± 0.3 Nm/deg.) was significantly smaller than in the Control group (4.8 ± 0.3 Nm/deg.). In the medio-cranial region, the magnitude of the maximum principal strain in the Square group (1176.4 ± 100.9) was significantly the largest (Control, 373.2 ± 129.5, p < 0.001; Long, 883.7 ± 153.3, p = 0.027; Short, 434.5 ± 196.8, p < 0.001; Square with mesh, 256.9 ± 100.8, p < 0.001). Torsional stiffness, and both maximum and minimum principal strains in the Short group showed no difference compared to the Control group in any region. CONCLUSIONS: Bone defect morphology greatly affected initial stem stability and load transmission. If defect morphology is not wide and the distal end is above the lower end of the lesser trochanter, it may be acceptable to fill the bone defect region with bone cement. However, this procedure is not acceptable for defects extending distally below the lower end of the lesser trochanter or defects 3 cm or more in width.


Assuntos
Artroplastia de Quadril/instrumentação , Fêmur/patologia , Prótese de Quadril/efeitos adversos , Falha de Prótese , Reoperação/instrumentação , Fenômenos Biomecânicos , Fêmur/cirurgia , Humanos , Desenho de Prótese , Telas Cirúrgicas
7.
Small ; 14(21): e1800676, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29665206

RESUMO

A simple route to fabricate defect-free Ag-nanoparticle-carbon-nanotube composite-based high-resolution mesh flexible transparent conducting electrodes (FTCEs) is explored. In the selective photonic sintering-based patterning process, a highly soft rubber or thin plastic substrate is utilized to achieve close and uniform contact between the composite layer and photomask, with which uniform light irradiation can be obtained with diminished light diffraction. This well-controlled process results in developing a fine and uniform mesh pattern (≈12 µm). The mesh patternability is confirmed to be dependent on heat distribution in the selectively light-irradiated film and the pattern design for FTCE could be adopted for more precise patterns with desired performance. Moreover, using a very thin substrate could allow the mesh to be positioned closer to the strain-free neutral mechanical plane. Due to strong interfacial adhesion between the mesh pattern and substrate, the mesh FTCE could tolerate severe mechanical deformation without performance degradation. It is demonstrated that a transparent heater with fine mesh patterns on thin substrate can maintain stability after 100 repeated washing test cycles in which a variety of stress situations occurring in combination. The presented highly durable FTCE and simple fabrication processes may be widely adoptable for various flexible, large-area, and wearable optoelectronic devices.

8.
Small ; 12(22): 3021-30, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27027390

RESUMO

A new structure of flexible transparent electrodes is reported, featuring a metal mesh fully embedded and mechanically anchored in a flexible substrate, and a cost-effective solution-based fabrication strategy for this new transparent electrode. The embedded nature of the metal-mesh electrodes provides a series of advantages, including surface smoothness that is crucial for device fabrication, mechanical stability under high bending stress, strong adhesion to the substrate with excellent flexibility, and favorable resistance against moisture, oxygen, and chemicals. The novel fabrication process replaces vacuum-based metal deposition with an electrodeposition process and is potentially suitable for high-throughput, large-volume, and low-cost production. In particular, this strategy enables fabrication of a high-aspect-ratio (thickness to linewidth) metal mesh, substantially improving conductivity without considerably sacrificing transparency. Various prototype flexible transparent electrodes are demonstrated with transmittance higher than 90% and sheet resistance below 1 ohm sq(-1) , as well as extremely high figures of merit up to 1.5 × 10(4) , which are among the highest reported values in recent studies. Finally using our embedded metal-mesh electrode, a flexible transparent thin-film heater is demonstrated with a low power density requirement, rapid response time, and a low operating voltage.

9.
Int J Urol ; 22(7): 629-36, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25950837

RESUMO

Extrinsic malignant compression of the ureter is not uncommon, often refractory to decompression with conventional polymeric ureteral stents, and frequently associated with limited survival. Alternative options for decompression include tandem ureteral stents, metallic stents and metal-mesh stents, though the preferred method remains controversial. We reviewed and updated our outcomes with tandem ureteral stents for malignant ureteral obstruction, and carried out a PubMed search using the terms "malignant ureteral obstruction," "tandem ureteral stents," "ipsilateral ureteral stents," "metal ureteral stent," "resonance stent," "silhouette stent" and "metal mesh stent." A comprehensive review of the literature and summary of outcomes is provided. The majority of studies encountered were retrospective with small sample sizes. The evidence is most robust for metal stents, whereas only limited data exists for tandem or metal-mesh stents. Metal and metal-mesh stents are considerably more expensive than tandem stenting, but the potential for less frequent stent exchanges makes them possibly cost-effective over time. Urinary tract infections have been associated with all stent types. A wide range of failure rates has been published for all types of stents, limiting direct comparison. Metal and metal-mesh stents show a high incidence of stent colic, migration and encrustation, whereas tandem stents appear to produce symptoms equivalent to single stents. Comparison is difficult given the limited evidence and heterogeneity of patients with malignant ureteral obstruction. It is clear that prospective, randomized studies are necessary to effectively scrutinize conventional, tandem, metallic ureteral and metal-mesh stents for their use in malignant ureteral obstruction.


Assuntos
Complicações Pós-Operatórias , Stents/efeitos adversos , Stents/classificação , Ureter/cirurgia , Obstrução Ureteral/cirurgia , Humanos , Stents/economia , Obstrução Ureteral/complicações , Infecções Urinárias/etiologia
10.
J Prosthodont ; 24(8): 661-4, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25659988

RESUMO

Mandibular implant-retained overdentures have become the standard of care for patients with mandibular complete edentulism. As part of the treatment, the mandibular implant-retained overdenture may require a metal mesh framework to be incorporated to strengthen the denture and avoid fracture of the prosthesis. Integrating the metal mesh framework as part of the acrylic record base and wax occlusion rim before the jaw relation procedure will avoid the distortion of the record base and will minimize the chances of processing errors. A simplified method to incorporate the mesh into the record base and occlusion rim is presented in this technique article.


Assuntos
Prótese Total Inferior , Revestimento de Dentadura , Prótese Dentária Fixada por Implante , Bases de Dentadura , Planejamento de Dentadura , Retenção de Dentadura , Humanos , Metais
11.
Nanomicro Lett ; 16(1): 92, 2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38252258

RESUMO

Despite the growing demand for transparent conductive films in smart and wearable electronics for electromagnetic interference (EMI) shielding, achieving a flexible EMI shielding film, while maintaining a high transmittance remains a significant challenge. Herein, a flexible, transparent, and conductive copper (Cu) metal mesh film for EMI shielding is fabricated by self-forming crackle template method and electroplating technique. The Cu mesh film shows an ultra-low sheet resistance (0.18 Ω â–¡-1), high transmittance (85.8%@550 nm), and ultra-high figure of merit (> 13,000). It also has satisfactory stretchability and mechanical stability, with a resistance increases of only 1.3% after 1,000 bending cycles. As a stretchable heater (ε > 30%), the saturation temperature of the film can reach over 110 °C within 60 s at 1.00 V applied voltage. Moreover, the metal mesh film exhibits outstanding average EMI shielding effectiveness of 40.4 dB in the X-band at the thickness of 2.5 µm. As a demonstration, it is used as a transparent window for shielding the wireless communication electromagnetic waves. Therefore, the flexible and transparent conductive Cu mesh film proposed in this work provides a promising candidate for the next-generation EMI shielding applications.

12.
ACS Appl Mater Interfaces ; 16(5): 6382-6393, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38279914

RESUMO

A facile and novel fabrication method is demonstrated for creating flexible poly(ethylene terephthalate) (PET)-embedded silver meshes using crack lithography, reactive ion etching (RIE), and reactive silver ink. The crack width and spacing in a waterborne acrylic emulsion polymer are controlled by the thickness of the polymer and the applied stress due to heating and evaporation. Our innovative fabrication technique eliminates the need for sputtering and ensures stronger adhesion of the metal meshes to the PET substrate. Crack trench depths over 5 µm and line widths under 5 µm have been achieved. As a transparent electrode, our flexible embedded Ag meshes exhibit a visible transmission of 91.3% and sheet resistance of 0.54 Ω/sq as well as 93.7% and 1.4 Ω/sq. This performance corresponds to figures of merit (σDC/σOP) of 7500 and 4070, respectively. For transparent electromagnetic interference (EMI) shielding, the metal meshes achieve a shielding efficiency (SE) of 42 dB with 91.3% visible transmission and an EMI SE of 37.4 dB with 93.7% visible transmission. We demonstrate the highest transparent electrode performance of crack lithography approaches in the literature and the highest flexible transparent EMI shielding performance of all fabrication approaches in the literature. These metal meshes may have applications in transparent electrodes, EMI shielding, solar cells, and organic light-emitting diodes.

13.
Data Brief ; 48: 109238, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37383753

RESUMO

Electrodeposited Ag mesh transparent conducting electrodes (TCEs) based on self-cracking templates can achieve high optical transmittances and low sheet resistances by controlling the shape of the self-cracking templates and electrodeposition duration. The surface coverage of the mesh is mainly determined by the surface shape of the self-cracking template. Electrodeposition of Ag can adjust the thickness of the mesh, significantly reducing the sheet resistance while maintaining the high optical transmittance of the TCEs. The TCE electrodeposited for 30 s exhibited an optical transmittance as high as 88.4% and a sheet resistance as low as 2.24 Ω/□. Here we provide the microstructural and optoelectronic performance data of the electrodeposited Ag mesh TCEs.

14.
J Funct Biomater ; 14(8)2023 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-37623664

RESUMO

Biocompatible polymers such as polymethyl methacrylate (PMMA), despite fulfilling biomedical aspects, lack the mechanical strength needed for hard-tissue implant applications. This gap can be closed by using composites with metallic reinforcements, as their adaptable mechanical properties can overcome this problem. Keeping this in mind, novel Ti-mesh-reinforced PMMA composites were developed. The influence of the orientation and volume fraction of the mesh on the mechanical properties of the composites was investigated. The composites were prepared by adding Ti meshes between PMMA layers, cured by hot-pressing above the glass transition temperature of PMMA, where the interdiffusion of PMMA through the spaces in the Ti mesh provided sufficient mechanical clamping and adhesion between the layers. The increase in the volume fraction of Ti led to a tremendous improvement in the mechanical properties of the composites. A significant anisotropic behaviour was analysed depending on the direction of the mesh. Furthermore, the shaping possibilities of these composites were investigated via four-point bending tests. High shaping possibility was found for these composites when they were shaped at elevated temperature. These promising results show the potential of these materials to be used for patient-specific implant applications.

15.
Nanomaterials (Basel) ; 13(2)2023 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-36677974

RESUMO

This paper proposes a dual-band transparent antenna using frame-structured metal mesh conductive film (MMCF). The frame-structured metal mesh conductive film is based on the conductive-coated thin film and forms a narrow strip surrounding the edge of the antenna. The frame-structured metal mesh conductive film can resist considerable current leakage on the edge of the conductive strip to improve the antenna's efficiency by 51% at 2.1 GHz and 53% at 3.6 GHz. As a result, the transparent dual-band antenna has an operating bandwidth of 1.9-2.4 GHz and 3.2-4.1 GHz with a high transparency of 80%, which make it valuable to the applications of biomedical electronic components, wearable devices, and automobile vehicles.

16.
ACS Appl Mater Interfaces ; 15(25): 30591-30599, 2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-37314726

RESUMO

We present a simulation and experimental study of silver meshes to determine their performance for transparent electromagnetic interference (EMI) shielding. Simulations were employed to study the effects of the silver mesh's width, pitch, and thickness on EMI shielding efficiency (SE) in the 8-18 GHz frequency range and transparency in the visible spectrum. We demonstrate a scalable, facile fabrication method that involves embedding meshes in glass by etching trenches in glass and filling and curing reactive particle-free silver ink in these trenches. Our silver meshes achieve 58.4 dB EMI SE with 83% visible light transmission and 48.3 dB EMI SE with 90.3% visible transmission. The combination of high-conductivity silver, small widths (1.3 to 5 µm), and large thicknesses (0.5 to 2.0 µm) enables the best performance of metal meshes as well as single-sided shielding materials for transparent EMI shielding, as reported in the literature.

17.
Materials (Basel) ; 16(4)2023 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-36837081

RESUMO

Corrosion under insulation (CUI) is a major threat to the structural integrity of insulated pipes and vessels. Pulsed eddy-current testing (PECT) is well known in the industry for detecting CUI, but its readings can be easily influenced by nearby conductive objects, including the insulation supporting metal mesh. As a sequel to our previous study, this paper focuses on the surface distribution of eddy currents at the time of the turning off of the driving voltage instead of examining the overall process of eddy current diffusion. Based on the fact that CUI takes place on the outside of the insulated specimen, the probe footprint was calculated only on the specimen surface. The corrosion depth was regarded as an increment to the probe lift-off, whose information was carried in the early PECT signal. Finite element simulations were performed to facilitate the calculation of the probe footprint and predict the signal behavior. The peak value, which appeared in the early phase of the differential PECT signal, was found to be well correlated with the corrosion depth. Further studies revealed that the mild steel mesh could result in the enlargement of the probe footprint and a decrease in the change rate of the peak value in relation to the corrosion depth. Finally, experiments were conducted to verify the simulation results. The presented findings are consistent with the previously reported results and provide a potential alternative to evaluate CUI in specific scenarios where the insulation has a fixed and uniform thickness.

18.
Orthop Surg ; 15(3): 750-757, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36644857

RESUMO

OBJECTIVE: In revision total hip arthroplasty (THA), reconstruction of severe acetabular bone defect continues to be problematic for orthopedic surgeons. This study reports the mid- to long-term survivorship, radiological outcomes, and complications of impaction bone grafting (IBG) and metal mesh with a cemented acetabular component in the reconstruction of severe acetabular bone defects in revision THA. METHODS: This retrospective consecutive study included 26 patients (29 hips: type II B, four; type II C, three; type III A, 10; and type III B, 12) who underwent revision THA, which was performed using IBG and metal mesh, between 2007 and 2014 in our institution. All patients were followed up regularly for clinical and radiographical assessments. Migration and loosening of prosthesis graft integration and complications were observed and analyzed. Survival analysis was performed using a Kaplan-Meier survival analysis. RESULTS: At the time of revision, 75.9% of the hips (22 hips) were classified as type III bone defects. The average follow-up period was 9.4 ± 2.8 (range, 2.4-14.0) years. Of the 29 hips, four hips (13.8%) were assessed as clinical failures; at the last follow-up, two had undergone re-revision THA, and two had not been scheduled for re-revision THA despite radiological failure of the acetabular component. Among them, three clinical failures (10.3%) were due to aseptic loosening, and one (3.4%) was due to infection. Radiographic evaluation showed bone graft integration in all hips during the follow-up. The Kaplan-Meier survivorship analysis revealed an acetabular reconstruction survival rate of 86.5% (95% confidence interval, 61.4%-95.7%) at 10 years. CONCLUSION: IBG and metal mesh with a cemented acetabular component for revision THA is an effective technique for treating severe acetabular bone defects, with effective mid- to long-term outcomes due to the solid reconstruction of the acetabular bone defect and restoration of the hip rotation center.


Assuntos
Artroplastia de Quadril , Prótese de Quadril , Humanos , Artroplastia de Quadril/métodos , Seguimentos , Transplante Ósseo/métodos , Telas Cirúrgicas , Estudos Retrospectivos , Resultado do Tratamento , Acetábulo/cirurgia , Reoperação , Falha de Prótese
19.
Phys Med Biol ; 67(13)2022 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-35667368

RESUMO

Objective.In charged-particle therapy, a ripple filter (RiFi) is used for broadening the Bragg peak in the beam direction. A conventional RiFi consists of plates with a fine ridge and groove structure. The construction of the RiFi has been a time-consuming and costly task. In this study, we developed a simple RiFi made of multi-layered metal mesh (mRiFi), with which the Bragg peak is broadened due to structural randomness, similar to what occurs for the already proposed RiFi with porous material.Approach. The mRiFi was constructed by stacking commercially available metal meshes at random positions and angles. The mRiFi was inexpensive to fabricate due to its high availability and low machining accuracy. The Bragg peak width modulated by the mRiFi can be uniquely determined by the wire material, wire diameter, wire-to-wire spacing of the metal mesh, and the number of mesh sheets. We fabricated four mRiFis consisting of 10, 20, 30, and 40 layers of stainless steel meshes with a wire diameter of 0.1 mm and a wire-to-wire spacing of 0.508 mm.Main results.Using the mRiFis consisting of 10, 20, 30, and 40 mesh sheets, we succeeded in broadening the Bragg peak following the normal distribution with the respective standard deviationσvalues of 0.83, 1.15, 1.41, and 1.56 mm in water in experimental planar-integrated depth dose measurements with 140.3 MeV u-1carbon-ion beams. The effect of range broadening with the mRiFi was independent of its lateral position, and the measurement of the surface dose using radiochromic films showed no severe inhomogeneity with a homogeneity index greater than 0.3 caused by the mRiFis.Significance.The developed mRiFi can be used as a RiFi in charged-particle therapy. The mRiFi has three advantages: high supply stability of the material for manufacturing it, easy fabrication, and low cost.


Assuntos
Carbono , Planejamento da Radioterapia Assistida por Computador , Carbono/uso terapêutico , Método de Monte Carlo , Distribuição Normal , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos
20.
Artigo em Inglês | MEDLINE | ID: mdl-35565166

RESUMO

Metal mesh devices (MMDs) are novel materials that enable the precise separation of particles by size. Structurally, MMDs consist of a periodic arrangement of square apertures of characteristic shapes and sizes on a thin nickel membrane. The present study describes the separation of aerosol particles using palm-top-size collection devices equipped with three types of MMDs differing in pore size. Aerosols were collected at a farm located in the suburbs of Nairobi, Kenya; aerosol particles were isolated, and pathogenic bacteria were identified in this microflora by next-generation sequencing analysis. The composition of the microflora in aerosol particles was found to depend on particle size. Gene fragments were obtained from the collected aerosols by PCR using primers specific for the genus Mycobacterium. This analysis showed that Mycobacterium obuense, a non-tuberculous species of mycobacteria that causes lung diseases, was present in these aerosols. These findings showed that application of this MMD analytical protocol to aerosol particles can facilitate the investigation of airborne pathogenic bacteria.


Assuntos
Bactérias , Metais , Aerossóis/análise , Bactérias/genética , Quênia , Tamanho da Partícula
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