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In this study, the complete mitochondrial DNA sequence of a hagfish Eptatretus sp. Nan-Hai from a depth of 1000 m is presented. The complete sequence was determined using next-generation sequencing and long PCRs. The mitochondrial genome of Eptatretus sp. Nan-Hai is 17,538 bps in size and composed of 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes, and one control region (D-loop). The base composition of mitochondrial genome is biased toward A + T content, at 67.21%, with GC skew of −0.35 and AT skew of −0.03. A phylogenetic tree revealed that within the genus Eptatretus, Eptatretus sp. Nan-Hai is closely related to Eptatretus atami.

Objective. The present study aimed to investigate the effect of fluoride-modified titanium surface on adhesion of irradiated osteoblasts.Materials and Methods. Fluoride-modified surface was obtained and the morphology, roughness, and chemical composition of the surface were evaluated by scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy, respectively. The adhesion of irradiated osteoblast-like cells, in terms of number, area, and fluorescence intensity on the titanium surface, was evaluated using immunofluorescence staining.Results. Numerous nanosize pits were seen only in the F-TiO surface. The pits were more remarkable and uniform on F-TiO surface than on TiO surface; however, the amplitude of peaks and bottoms on F-TiO surface appeared to be smaller than on TiO surface. The Sa value and Sdr percentage of TiO surfaces were significantly higher than those of F-TiO surface. The concentrations of main elements such as titanium, oxygen, and carbon were similar on both surfaces. The number of irradiated osteoblasts adhered on the control surface was larger than on fluoride-modified surface. Meanwhile, the cells on the fluoride-modified surface formed more actin filaments.Conclusions. The fluoride-modified titanium surface alters the adhesion of irradiated osteoblasts. Further studies are needed to investigate the proliferation, differentiation, maturation, gene expression, and cytokine production of irradiated osteoblasts on fluoride-modified titanium surface.

The gut microbiota is contributable to the adaptation and health of deep-sea organisms and has been revealed to be affected by many factors, especially the host species and diet. Here, we employed high-throughput sequencing of 16S rDNA to compare the gut microbial composition and diversity of two hadal amphipod species, Hirondellea gigas and Halice sp. MT-2017, which are predominant inhabitants in the Challenger Deep. Results showed that Tenericutes and Proteobacteria were the most abundant phyla, occupying more than 50% of total phyla, across all the specimens. At genus level, “Candidatus Hepatoplasma” was overall dominant, followed by Psychromonas in H. gigas and Psychrobacter in Halice sp. MT-2017 respectively. Notably, though two hadal amphipod species shared the same predominant symbiont of genus “Ca. Hepatoplasma”, they were classified into two different OTUs, which suggested that the colonization of symbionts were host-specific. Moreover, in terms of species relative abundance, alpha-diversity and beta-diversity, there was still a significant divergence of gut microbiota between two hadal amphipod species, which dwelled in the same extreme environment. Altogether, the results dropped a hint to the importance of symbiont genus of “Ca. Hepatoplasma” to amphipod survival in the hadal zone.

Radiotherapy may compromise the integration of implant and cause implant loss. Implant surface modifications have the possibility of promoting cell attachment, cell growth, and bone formation which ultimately enhance the osseointegration process. The present study aimed to investigate the effects of calcium phosphate nanocrystals on implant osseointegration in irradiated bone. Sixteen rabbits were randomly assigned into control and nano-CaP groups, receiving implants with dual acid-etched surface or dual acid-etched surface discretely deposited of nanoscale calcium-phosphate crystals, respectively. The left leg of all the rabbits received 15 Gy radiation, followed by implants placement one week after. Four animals in each group were sacrificed after 4 and 12 weeks, respectively. Implant stability quotient (ISQ), ratio of bone volume to total volume (BV/TV), bone growth rate, and bone-to-implant contact (BIC) were evaluated. The nano-CaP group showed significantly higher ISQ (week 12, P = 0.031) and bone growth rate (week 6, P = 0.021; week 9, P = 0.001) than that in control group. No significant differences in BV/TV and BIC were found between two groups. Titanium implant surface modified with CaP nanocrystals provides a potential alternative to improve bone healing around implant in irradiated bone., published_or_final_version