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Solidification of Al–Ce alloys under ultrasonic vibrations (Sonoprocessing) has a significant effect on the refining of Al11Ce3 intermetallic, which plays a key role in controlling the properties of this group of high-performance characteristics. In the current research, a group of as-received Al-10 wt% Ce alloys that were sonoprocessed under different temperatures was characterized. The influence of Al11Ce3 intermetallic size and distribution on the electrochemical properties of these alloys was investigated. Polarization tests in 3.5% NaCl solution were carried out and the recorded Tafel and impedance curves were studied. The corrosion test results were related to the microstructure characteristics as affected by sonoprocessing. Investigation of the as-received samples showed that ultrasonic vibrations broke the long lath-shaped particles of Al11Ce3 and obviously decreased their size and increased their surface area fraction. Sonoprocessing at the optimum temperature, 655 °C, reduced the Al11Ce3 particles size by 90% and enhanced their distribution in the matrix. This in its turn resulted in significant effects on their electrochemical behavior. Polarization tests showed that the corrosion rate of the un-sonoprocessed specimen decreased from ~ 0.00068 to 0.00006 mm/year after processing at the optimum condition (655 °C), and the polarization resistance increased from ~ 71 to 343 kΩ. By increasing the temperature of ultrasonic treatment beyond 655 °C, and the corresponding coarsening of the intermetallic particles, the corrosion rate slowly increased again, and concurrently, the polarization resistance decreased. The size and distribution of the intermetallic particles also influenced the formation of the corrosion pits, where the optimum sample showed shallow pits compared to those observed in the unprocessed specimen. This emphasizes the role of sonoprocessing in controlling the microstructure features and hence the electrochemical properties of Al-10 wt% Ce alloys. [ABSTRACT FROM AUTHOR]

Background: Bone tissue regeneration requires the development of safe and effective biodegradable scaffolds made of biomaterials with bone composition mimic coating. This study aimed to assess the osteoinduction potentiality of pure Mg- implant before and after coating with different CNT composite coating; CNT and chitosan alone or hybridized with calcium phosphate. Methods: UDMSCs were cultured on the Pure Mg, Mg disks coated by CNT and Chitosan, Mg disks coated by CNT/ Chitosan/ di-calcium phosphate, and Mg disks coated by CNT/ Chitosan /HA (fine and coarse). The osteoblasts’ differentiation was assessed by alizarin red staining. Crystal violet was used to assess cell viability percent of each of the investigated surfaces. The functionality of osteoblasts was assessed by ALP and Ca amount. Results: All the investigated surfaces led to an osteoblasts differentiation except the surface hybrid with di-Cap. Least cell viability was recorded with pure Mg and Mg coated by CNT and Chitosan composite 85 and 80%, respectively. Mg coated by CNT / Chitosan/di-Cap composite recorded the least amount of ALP ad Ca amount; 0.8 ± 0.39 And 0.8 ±0.27, respectively. Whereas the composite coating contained CNT/Chitosan and HA coarse hybrid with CNT / Chitosan recorded the highest significant higher ALP and Ca amount. Conclusions: Pure Mg surface coated with CNT, Chitosan, and HA composite has an osteoinductive potentiality. Using Mg surface coated by calcium phosphate compounds hybrid with CNT and Chitosan enhanced the viability and lessened the cytotoxicity of the osteoblasts. [ABSTRACT FROM AUTHOR]

Objective: The present randomised controlled trial is based on the null hypothesis that there is no difference in crestal bone levels (CBLs) following socket preservation (SP) using platelet-rich fibrin (PRF) and free gingival graft (FGG). The aim was to evaluate CBLs following SP using PRF and FGG., Methods: This study is a parallel-arm randomised controlled trial. Patients in the test and control groups underwent SP using PRF and FGG, respectively. Intraoral visual examination was performed to clinically assess signs of swelling, pus/abscess, and stability of sutures and graft. Self-rated postoperative pain was assessed after 1 week and 6 months using the visual analogue scale (VAS). At the 6-month follow-up, cone-beam computed tomography was performed to evaluate CBL in mesiodistal and buccolingual dimensions. The preoperative cone-beam computed tomographic images were superimposed with those taken at the 6-month follow-up to compare CBLs. Statistical comparisons were performed and level of significance was set at P < .05., Results: The test and control groups each comprised 13 individuals with comparable ages. All teeth included in the test and control groups were located in the maxillary aesthetic zone. At the 1-week follow-up, VAS scores were higher in the control than in the test group (P < .01). At the 6-month follow-up, none of the participants reported self-rated pain. The change in buccolingual dimension was greater in the control group than in the test group (P < .05)., Conclusions: Both FGG and PRF are effective techniques for SP; however, the latter technique is more effcacious in maintaining buccolingual dimensions of the extraction socket., Competing Interests: Conflict of interest None disclosed., (Copyright © 2024. Published by Elsevier Inc.)

The study examines the impact of microstructure and polymethyl methacrylate (PMMA) grafting on the degradability of Zn-Mg alloys. The mechanical properties of a Zn alloy containing 0.68 wt% Mg and extruded at 200 °C are enhanced for degradable load-bearing applications, addressing a crucial need in the field. The material exhibits a bimodal grain size distribution that is random texture, consisting of secondary phases, grains, and sub-grains. With an elongation to failure of 16 %, the yield and ultimate tensile strengths are 325.9 and 414.5 MPa, respectively, and the compressive yield strength is 450.5 MPa. The "grafting-from" method was used to coat a few micrometers thick of PMMA on both bulk and scaffold Zn alloys to mitigate the corrosion rate. The last one is a porous structure, with a porosity of 65.8 %, considered as in the first approach of an orthopedic implant. After being immersed for 720 h, the PMMA-grafted bulk alloy's corrosion rate decreased from 0.43 to 0.25 mm/y. Similarly, the scaffold alloy's corrosion rate reduced from 1.24 to 0.49 mm/y. These results indicate that the method employed could be used for future orthopedic applications., (© 2024 The Authors.)

Although zinc (Zn) is one of the elements with the greatest potential for biodegradable uses, pure Zn does not have the ideal mechanical or degrading properties for orthopaedic applications. The current research aims at studying the microstructure and corrosion behaviour of pure Zn (used as a reference material) and Zn alloyed with 1.89 wt.% magnesium (Mg), both in their extruded states as well as after being coated with polymethyl methacrylate (PMMA). The grafting-from approach was used to create a PMMA covering. The "grafting-from" method entails three steps: the alkali activation of the alloys, their functionalization with an initiator of polymerization through a phosphonate-attaching group, and the surface-initiated atom transfer radical polymerisation (SI-ATRP) to grow PMMA chains. Electrochemical and immersion corrosion tests were carried out in a simulated body fluid (SBF), and both confirmed the enhanced corrosion behaviour obtained after coating. The electrochemical test revealed a decrease in the degradation rate of the alloy from 0.37 ± 0.14 mm/y to 0.22 ± 0.01 mm/y. The immersion test showed the ability of complete protection for 240 h. After 720 h of immersion, the coated alloy displays minute crevice corrosion with very trivial pitting compared to the severe localized (galvanic and pitting) corrosion type that was detected in the bare alloy.

Psoriasis is an immune-mediated skin disease with a potential morbidity in patients. Cold-inducible RNA binding protein (CIRP) is a stress responsive protein having diverse roles in cancer and inflammation. This study aimed to evaluate the expression of CIRP, (serum and tissue), in psoriasis patients and to correlate this expression to the clinico-pathological data of the patients. The serum level and tissue expression of CIRP were compared between 20 patients and 20 healthy controls. Additionally, the association between CIRP level and various clinicopathological parameters was done. The serum level of CIRP was measured by enzyme-linked immunosorbent assay (ELISA) while its tissue expression was detected via immunohistochemistry. CIRP was expressed in the epidermis of all studied cases and controls with nuclear localization. A significant difference in its epidermal expression between lesional, perilesional cases and controls was observed. It was higher in control epidermis than perilesional skin and the lowest in lesional skin. Conversely, the serum CIRP level was significantly higher in psoriasis patients compared to healthy subjects. CIRP seemed to have a significant pathologic role in psoriasis patients with evident difference in its intracellular and extracellular expression levels suggesting a potential difference it its function.

Psoriasis is a chronic immune-mediated inflammatory disease, affecting about 2 to 3% of the population worldwide. Nucleotide-binding and oligomerization domain 2-like receptor has been implicated in the pathogenesis of different inflammatory diseases. The current work aims to investigate the expression of nucleotide-binding and oligomerization domain 2-like receptor in psoriatic skin through an immunohistochemical study. This cross-sectional case-control study included 20 patients with chronic plaque psoriasis and 20 age- and sex-matched normal subjects as controls. Psoriasis severity was assessed through the use of Psoriasis Area Severity Index (PASI) score. Skin biopsies were taken under local anesthesia from cases and from matched sites of controls. Expression of nucleotide-binding and oligomerization domain 2 in epidermis of studied cases and controls showed positive epidermal expression of nucleotide-binding and oligomerization domain 2 in all cases (100%) versus 6 (30%) controls with a significant increase (χ2 = 21.54, P ˂0.001). Moreover, dermal expression of nucleotide-binding and oligomerization domain 2 was higher in psoriatic skin lesion (95%) compared to controls (15%) with a significant difference (χ2 = 25.86, P ˂0.001). We concluded that nucleotide-binding and oligomerization domain 2 may be implicated in psoriasis pathogenesis being higher in cases in comparison to controls.

COVID-19 mainly causes a lower respiratory tract illness, meaning there has been great interest in the chest and lung radiological findings seen during the course of the disease. Most of this interest has centred around the computed tomographic findings. Most commonly, computed tomographic images report ground-glass opacities but a less common finding, and potential complication associated with COVID-19, is pneumatocele formation. In this case series, we describe the presentation and management of three patients with large pneumatoceles that developed during the recovery phase of COVID-19. A conservative approach is most recommended, with surgical intervention reserved for complicated cases that cause cardiorespiratory compromise.