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Journal of Applied Biomaterials &... 2024This study aims to investigate the effect of coating time on the formation of hydroxyapatite (HA) coating layer on ZK60 substrate and understand the biodegradation...
OBJECTIVES
This study aims to investigate the effect of coating time on the formation of hydroxyapatite (HA) coating layer on ZK60 substrate and understand the biodegradation behavior of the coated alloy for biodegradable implant applications.
METHODS
Biodegradable ZK60 alloy was coated by HA layer for different times of 0.5, 1, 2, and 4 h by chemical conversion method. After coating, all the coated specimens were used for immersion test in Hanks' solution to understand the effect of coating time on the degradation behavior of the alloy. The degradation rate of the coated alloy was evaluated by Mg ion quantification and pH change during immersion test. The microstructure of the coating layer was examined by scanning electron microscope (SEM) equipped with an energy-dispersive X-ray spectroscopy (EDS) before and after immersion to understand the degradation behavior of the coated alloy.
RESULTS
HA coating layers were formed successfully on surface of ZK60 specimens after 0.5, 1, 2, and 4 h with different microstructure. Optimal coating quality was observed at 1 or 2 h, characterized by well-formed and uniform HA layers. However, extending the coating duration to 4 h led to the formation of cracks within the HA layer, accompanied by Mg(OH). Specimens coated for 1 and 2 h exhibited the lowest degradation rates, while specimens coated for 0.5 and 4 h showed the highest degradation rates. Furthermore, analysis of degradation products revealed the predominance of calcium phosphates formed on the surface of specimens coated for 1 and 2 h. Conversely, specimens coated for 0.5 and 4 h exhibited Mg(OH) as the primary degradation product, suggesting a less effective corrosion barrier under these conditions.
CONCLUSION
The HA layer formed after 2 h demonstrated as the most effective coating layer for enhancing the corrosion resistance of the ZK60 alloy for biomedical applications.
Topics: Durapatite; Alloys; Coated Materials, Biocompatible; Materials Testing; Corrosion; Magnesium
PubMed: 38912599
DOI: 10.1177/22808000241251564 -
Heliyon Jun 2024In this work, a bibliometric study was carried out to perform a scientific and technological analysis of exchange-spring magnets, an alternative permanent magnet... (Review)
Review
In this work, a bibliometric study was carried out to perform a scientific and technological analysis of exchange-spring magnets, an alternative permanent magnet synthesized by reducing or eliminating the use of critical raw materials, such as rare earths. The bibliometric analysis utilized the Scopus database, Orbit-Intellixir, VOSviewer, Orbit-Intelligence and Loglet Lab 4 software for maturity analysis, keyword network representations, charts and graphs for scientific articles and/or patents. A special analysis was performed on nanocomposite and thin-films systems based on Nd-Fe-B, SmCo and Mn-Al-C alloys, either mixed or layered with a soft magnetic phase, where relevant information on their magnetic parameters was compilated in tables, highlighting the nanostructured systems that have been exhibited the best permanent magnet properties. The bibliometric analysis revealed that the primary production of scientific articles is concentrated in industrialized countries, and they are predominantly published in journals dedicated to magnetism. A patents analysis showed that Nissan motors is by far the main applicant, with most of its patents is focused on technological domains related to electrical machinery, apparatus, energy and metallurgy. On the other hand, the S-curve of maturity for scientific articles indicated that the study of exchange-spring magnets is entering a mature state. In contrast, patent production, following a bi-logistic model, is in a saturation stage for the second S-curve. Maturity analyses, employing S-curve, bi-logistic and multi-logistic models, were performed on nanocomposites and thin films based on Nd-Fe-B, SmCo and Mn-Al-C alloys, respectively. We found that the investigation in Nd-Fe-B-based alloys is close to enter to a scientific saturation stage, while an average growth stage is observed for the SmCo and Mn-Al-C-based alloys. This suggests that research on alternative magnets, capable of fulfilling technological applications where a Nd-Fe-B magnets are commonly used, is a topic of significant interest.
PubMed: 38912490
DOI: 10.1016/j.heliyon.2024.e32358 -
F1000Research 2023Pediatric dental treatment is challenging in patients with early childhood caries. For clinician its difficult to manage child and provide good work at the same time.... (Comparative Study)
Comparative Study
BACKGROUND
Pediatric dental treatment is challenging in patients with early childhood caries. For clinician its difficult to manage child and provide good work at the same time. Its necessity to have the best equipments as well as materials. Nowadays, aesthetics play an important role in managing decayed teeth. Zirconia crown is better option but requires excessive preparation. As Bioflx is newly developed crown and has combined stainless steel and zirconia properties.
AIM
To assess the clinical performance and child and parental satisfaction of Bioflex crowns compared to zirconia and stainless steel crowns.
METHODS
In this comparative study of Bioflx crowns with zirconia and stainless steel crowns, children aged three to seven years old will be selected, and 72 primary teeth requiring crowns will be randomly distributed into three groups, n = 24: Preformed stainless steel crown, control; Preformed Bioflex crown; Preformed zirconia crown. Crowns will be evaluated for recurrent caries, plaque accumulation, restoration failure, gingival status opposing tooth wear, and clinicians and parental satisfaction at zero, three, six, and 12 months.
RESULTS
Bioflx crown will have better clinical as well as parental satisfaction among zirconia and stainless steel crowns.
CONCLUSIONS
The Bioflx crown can be used as an alternative economical esthetic full-coronal restoration for primary teeth.
TRIAL REGISTRATION
CTRI registration number: CTRI/2023/05/052256; Date of registration: May 03, 2023.
PROTOCOL VERSION
Two; Date: April 22, 2023.
Topics: Zirconium; Stainless Steel; Crowns; Pediatric Dentistry; Humans; Male; Female; Child, Preschool; Child; Patient Satisfaction
PubMed: 38911945
DOI: 10.12688/f1000research.133464.2 -
ACS Omega Jun 2024In order to reduce infections, porous NiTi alloys with 62% porosity were obtained by self-propagating high-temperature synthesis with the addition of 0.2 and 0.5 at. %...
In order to reduce infections, porous NiTi alloys with 62% porosity were obtained by self-propagating high-temperature synthesis with the addition of 0.2 and 0.5 at. % silver nanoparticles. Silver significantly improved the alloys' antibacterial activity without compromising cytocompatibility. An alloy with 0.5 at. % Ag showed the best antibacterial ability against . All alloys exhibited good biocompatibility with no cellular toxicity against embryonic fibroblast 3T3 cells. Clinical evaluation of the results after implantation showed a complete absence of purulent-inflammatory complications in all animals. Even distribution of silver nanoparticles in the surface layer of the porous NiTi alloy provides a uniform antibacterial effect.
PubMed: 38911803
DOI: 10.1021/acsomega.3c08163 -
ACS Energy Letters Jun 2024Silicon's potential as a lithium-ion battery (LIB) anode is hindered by the reactivity of the lithium silicide (Li Si) interface. This study introduces an innovative...
Silicon's potential as a lithium-ion battery (LIB) anode is hindered by the reactivity of the lithium silicide (Li Si) interface. This study introduces an innovative approach by alloying silicon with boron, creating boron/silicon (BSi) nanoparticles synthesized via plasma-enhanced chemical vapor deposition. These nanoparticles exhibit altered electronic structures as evidenced by optical, structural, and chemical analysis. Integrated into LIB anodes, BSi demonstrates outstanding cycle stability, surpassing 1000 lithiation and delithiation cycles with minimal capacity fade or impedance growth. Detailed electrochemical and microscopic characterization reveal very little SEI growth through 1000 cycles, which suggests that electrolyte degradation is virtually nonexistent. This unconventional strategy offers a promising avenue for high-performance LIB anodes with the potential for rapid scale-up, marking a significant advancement in silicon anode technology.
PubMed: 38911534
DOI: 10.1021/acsenergylett.4c00856 -
RSC Advances Jun 2024High entropy alloys (HEAs) exhibit superior mechanical properties. However, the nanoscratching properties and deformation behaviour of FeCoCrNiAl0.5 HEAs remain unknown...
High entropy alloys (HEAs) exhibit superior mechanical properties. However, the nanoscratching properties and deformation behaviour of FeCoCrNiAl0.5 HEAs remain unknown at the nanoscale. Here, we investigate the effect of scratching depth on the microstructural and tribological characteristics of an FeCoCrNiAl0.5 HEA using molecular dynamics simulations combined with a physical model. The scratching force increases significantly as the scratching depth increases. In the lower part of the scratching region, there is a clear atomic movement process, with the load generated in the normal direction causing the atoms to shift downwards. Noticeable shear bands are formed in the subsurface area, and they are both small and narrow compared with the pure Ni. The plastic deformation mechanism of the compressed surface is mainly governed by the formation and expansion of stacking faults during the subsurface evolution process. The evolution process of screw dislocations is similar to that of edge dislocations. In addition, the high strength and deformation resistance of FeCoCrNiAl0.5 HEAs are further evaluated by establishing a microstructure-based physical model. The combined effect of the lattice distortion strengthening and dislocation strengthening promotes the high strength of the FeCoCrNiAl0.5 HEA, which is significantly better than the single strengthening mechanism of pure metals. These results accelerate the understanding of the mechanical properties and deformation mechanisms of HEAs.
PubMed: 38911269
DOI: 10.1039/d4ra02422b -
Bioactive Materials Oct 2024For gastrointestinal anastomosis, metallic biodegradable staples have a broad application potential. However, both magnesium and zinc alloys have relatively low strength...
For gastrointestinal anastomosis, metallic biodegradable staples have a broad application potential. However, both magnesium and zinc alloys have relatively low strength to withstand the repeated peristalsis of the gastrointestinal tract. In this study, we developed a novel kind of biodegradable high-nitrogen iron (HN-Fe) alloy wires (0.23 mm), which were fabricated into the staples. The tensile results showed that the ultimate tensile strength and elongation of HN-Fe wires were 1023.2 MPa and 51.0 %, respectively, which was much higher than those of other biodegradable wires. The degradation rate of HN-Fe wires was slightly higher than that of pure Fe wires. After 28 days of immersion, the tensile strength of HN-Fe wires remained not less than 240 MPa, meeting the clinical requirements. Furthermore, sixteen rabbits were enrolled to conduct a comparison experiment using HN-Fe and clinical Ti staples for gastroanastomosis. After 6 months of implantation, a homogeneous degradation product layer on HN-Fe staples was observed and no fracture occurred. The degradation rate of HN-Fe staples was significantly higher than that , and they were expected to be completely degraded in 2 years. Meanwhile, both benign cutting and closure performance of HN-Fe staples ensured that all the animals did not experience hemorrhage and anastomotic fistula during the observation. The anastomosis site healed without histopathological change, inflammatory reaction and abnormal blood routine and biochemistry, demonstrating good biocompatibility of HN-Fe staples. Thereby, the favorable performance makes the HN-Fe staples developed in this work a promising candidate for gastrointestinal anastomosis.
PubMed: 38910967
DOI: 10.1016/j.bioactmat.2024.06.005 -
Scientific Reports Jun 2024Excellent strength-ductility balance in metastable Fe-Cr-Ni austenitic alloys stems from phase transformation from austenite (fcc structure) to α' martensite (bcc...
Excellent strength-ductility balance in metastable Fe-Cr-Ni austenitic alloys stems from phase transformation from austenite (fcc structure) to α' martensite (bcc structure) during deformation, namely deformation-induced α' martensitic transformation (DIMT). Here, DIMT in a metastable Fe-17Cr-7Ni austenitic alloy was detected in situ and characterized in three dimensions (3D) by employing synchrotron radiation X-ray microtomography. This technique utilizes refraction contrast, which is attributable to the presence of phase boundaries between the parent austenite and the newly formed α' martensite phase. By combining microtomography and position-sensitive X-ray diffraction, we succeeded in crystallographically identifying multiple α' martensite phases continuously transformed in four groups from a single parent austenitic phase.
PubMed: 38910158
DOI: 10.1038/s41598-024-65505-3 -
Medicine Jun 2024The research focused on the postoperative effect of using interbody fusion cage in lumbar posterior lamina decompression and interbody fusion with pedicle screw by...
BACKGROUND
The research focused on the postoperative effect of using interbody fusion cage in lumbar posterior lamina decompression and interbody fusion with pedicle screw by comparing the postoperative effect of using 3D printing (Ti6Al4V) and PEEK material interbody fusion cage.
METHODS
Ninety-one patients with lumbar degenerative diseases from the Department of Spine Surgery of Tianjin Hospital were included in the study cohort. They were divided into 3D group (n = 39) and PEEK group (n = 52) according to the use of interbody fusion cage. The imaging data of the patients were collected and the postoperative data of the 2 groups were compared to evaluate patients' health status and the recovery of lumbar structure and function after operation.
RESULTS
Combined with the degree of fusion, the clinical effect of 3D printing titanium alloy interbody fusion cage was comprehensively judged. At the last follow-up, the JOA score, ODI index, VAS, prolo function score, and SF-36 scale of the 2 groups showed that the clinical symptoms were better than those before operation (P < .05). The height of intervertebral disc, the area of intervertebral foramen and the physiological curvature of lumbar vertebrae increased in varying degrees after operation (P < .05). At the last follow-up, the vertebral cage fusion rates were as high as 89.13% and 90.91% in the 3D and PEEK groups, with collapse rates of 6.5% and 4.5%, respectively. There were 10 cases of cage displacement in 3D group and 7 cases of cage displacement in PEEK group. There was no significant difference between the 2 groups (P > .05).
CONCLUSIONS
In conclusion, 3D printed (Ti6Al4V) interbody fusion cage can obtain good clinical effect in the surgical treatment of lumbar degenerative diseases. Posterior lumbar lamina decompression, bilateral pedicle screw fixation combined with 3D printed cage interbody fusion is excellent in rebuilding the stability of lumbar vertebrae. 3D printed interbody fusion cage can be an ideal substitute material for intervertebral bone grafting. The stable fusion time of interbody fusion cage after lumbar fusion is mostly from 3 months to half a year after operation.
Topics: Humans; Spinal Fusion; Printing, Three-Dimensional; Titanium; Male; Lumbar Vertebrae; Female; Middle Aged; Alloys; Retrospective Studies; Pedicle Screws; Benzophenones; Polymers; Aged; Polyethylene Glycols; Ketones; Treatment Outcome; Decompression, Surgical; Adult; Intervertebral Disc Degeneration
PubMed: 38905365
DOI: 10.1097/MD.0000000000038431 -
Science Advances Jun 2024Atomically dispersed Pt-group metals are promising as nanocatalysts because of their unique geometric structures and ultrahigh atomic utilization. However, loading...
Atomically dispersed Pt-group metals are promising as nanocatalysts because of their unique geometric structures and ultrahigh atomic utilization. However, loading isolated Pt-group metals in single-atom alloys (SAAs) with distinctive bimetallic sites is challenging. In this study, we present amorphous mesoporous Ni boride (Ni-B) as an ideal substrate to uniformly disperse Pt atoms with tunable loadings (1.7 to 12.2 wt %). The effect of the morphology, composition, and crystal phase of the Ni-B host on the growth and dispersion of Pt atoms is discussed. The resulting amorphous Pt-Ni-B mesoporous nanospheres exhibit superior electrocatalytic H evolution performance in acidic media. This strategy holds the potential to synthesize a diverse library of mesoporous amorphous Pt-group SAAs, by leveraging functional amorphous nanostructured 3 transition-metal borides as substrates, thereby proposing a comprehensive strategy to control atomically dispersed Pt-group metals.
PubMed: 38905333
DOI: 10.1126/sciadv.ado2442