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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 Mg2+ 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)2. 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)2 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. [ABSTRACT FROM AUTHOR]

Background: Adrenoleukodystrophy (ALD) is a rare sex-linked recessive disorder that disrupts adrenal gland function and the white matter of the nervous system. According to recent epidemiological statistics, up to this moment, the disease is the most recorded peroxisomal disorder. ABCD1 is a gene related to ALD, with more than 850 unique mutations have been reported. Early diagnosis of the disease would help to consult families with ALD to plan for interventions to prevent passing along the pathogenic mutations to their children. Material and Methods: A heterozygous ABCD1 gene mutation related to ALD found in a Vietnamese woman was used to design primers for the polymerase chain reaction (PCR) to amplify the segment spanning the mutation. Then, combining sequencing methods for the PCR products, especially Sanger sequencing and next-generation sequencing (NGS), a protocol was developed to detect mutations on the ABCD1 gene to apply for the DNA samples of in-vitro fertilization (IVF) embryos biopsied at the blastocyst stage to screen for pathogenic alleles. Results: The established protocol for PGD of ALD detected mutant alleles in 5/8 embryos (62.5%), while the remaining 3 embryos (37.5%) did not carry any mutation. One of the 3 embryos was transferred, and a healthy female baby was born after a full-term pregnancy. Conclusion: The developed protocol was helpful for the preimplantation genetic diagnosis process to help families with the monogenic disease of ALD but wish to have healthy children. [ABSTRACT FROM AUTHOR]