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The Qinghai Lake National Nature Reserve (QLNNR), renowned for its abundant natural resources and diverse ecological habitats, serves as an ideal environment for ticks, thereby increasing the risk of various tick-borne pathogens (TBPs) transmission. This study aimed to investigate the prevalence of TBPs in ticks collected from Przewalski's gazelle and Tibetan sheep within the QLNNR. A total of 313 tick samples were collected from the vicinity of Qinghai Lake. Tick species identification was conducted using both morphological and molecular biology techniques. Polymerase chain reaction (PCR) amplification was performed to detect the presence of spotted fever group (SFG) Rickettsia , Coxiella burnetii , Anaplasma phagocytophilum , Babesia microti , Theileria spp, Borrelia burgdorferi , Brucella spp, and Anaplasma ovis was performed using specific primers. Positive samples were sequenced and analyzed using BLASTn, followed by phylogenetic tree construction. The ticks collected from the Qinghai Lake area were identified as Dermacentor nuttalli . The overall prevalence rates of ticks carrying SFG Rickettsia and C. burnetii were 42.8 % (134/313) and 4.8 % (15/313), respectively. Three SFG Rickettsia species were detected, including R. raoultii 33.9 % (106/313), R. slovaca 3.8 % (12/113) and R. sibirica 7.7 % (24/113), with R. raoultii being the predominant species. The prevalence rates of SFG Rickettsia and C. burnetii in ticks from Tibetan sheep was 44.7 % (115/257) and 4.7 % (12/257), respectively,and in ticks from Przewalski's gazelle were 33.9 % (19/56) and 5.4 % (3/56). Furthermore, the study revealed a positive linear relationship between the abundance of Przewalski's gazelle and the number of ticks, as well as the prevalence of TBPs. The current study has identified Dermacentor nuttalli as the predominant tick vector species within the QLNNR region. The detection of SFG Rickettsia and C. burnetii has augmented our understanding of the epidemiological profile of ticks and TBPs in this area, thereby providing a robust theoretical foundation for the implementation of effective prevention and control strategies against TBPs., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024 Published by Elsevier Ltd.)

Background: Ticks are ectoparasites that feed on blood and pose a threat to both the livestock industry and public health due to their ability to transmit pathogens through biting. However, the impact of factors such as bloodmeal and geographic regions on the bacterial microbiota of Haemaphysalis qinghaiensis remains poorly understood., Methods: In this study, we used the v3-v4 region of the 16S rRNA gene to sequence the microbiota of Haemaphysalis qinghaiensis from eight groups (HY&#95;M, YS&#95;M, XH&#95;M, LD&#95;M, BM&#95;M, LD&#95;F&#95;F, LD&#95;F, and BM&#95;F&#95;F) in Qinghai Province., Results: Significant differences in bacterial richness were observed between LD&#95;F&#95;F, BM&#95;F&#95;F, and LD&#95;F ( P  < 0.01), and among the five groups (HY&#95;M, YS&#95;M, XH&#95;M, BM&#95;M, and LD&#95;M) ( P  < 0.05). The bacterial diversity also differed significantly between LD&#95;F&#95;F, LD&#95;F, and BM&#95;F&#95;F ( P  < 0.01), as well as among the five groups (HY&#95;M, YS&#95;M, XH&#95;M, LD&#95;M, and BM&#95;M) ( P  < 0.01). The group with the highest number of operational taxonomic units (OTUs) was LD&#95;F, accounting for 23.93 % (419/1751), while BM&#95;F&#95;F accounted for at least 0.80 % (14/1751). At the phylum level, Firmicutes was the most abundant, with relative abundance ranging from 7.44 % to 96.62 %. At the genus level, Staphylococcus had the highest abundance, ranging from 1.67 % to 97.53 %. The endosymbiotic bacteria Coxiella and Rickettsia were predominantly enriched in LD&#95;F&#95;F. Additionally, the 16S gene of Coxiella showed the highest identity of 99.07 % with Coxiella sp. isolated from Xinxiang hl9 (MG9066 71.1), while the 16S gene of Rickettsia had 100 % identity with Candidatus Rickettsia hongyuanensis strains (OK 662395.1). Functional predictions for the prokaryotic microbial community indicated that the main functional categories were Metabolic, Genetic information processing, and Environmental information processing across the eight groups., Conclusion: This study provides a theoretical basis for the prevention and treatment of tick-borne diseases, which is of great significance for public health., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Yaks are the main pillar of plateau animal husbandry and the material basis of local herdsmen's survival. The level of mineral elements in the body is closely related to the production performance of yaks. In this study, we performed a comprehensive analysis of rumen epithelial morphology, transcriptomics and metagenomics to explore the dynamics of rumen functions, microbial colonization and functional interactions in yaks from birth to adulthood. Bacteria, eukaryotes, archaea and viruses colonized the rumen of yaks from birth to adulthood, with bacteria being the majority. Bacteroidetes and Firmicutes were the dominant phyla in five developmental stages, and the abundance of genus Lactobacillus and Fusobacterium significantly decreased with age. Glycoside hydrolase (GH) genes were the most highly represented in five different developmental stages, followed by glycosyltransferases (GTs) and carbohydrate-binding modules (CBMs), where the proportion of genes coding for CBMs increased with age. Integrating host transcriptome and microbial metagenome revealed 30 gene modules related to age, muscle layer thickness, nipple length and width of yaks. Among these, the MEmagenta and MEturquoise were positively correlated with these phenotypic traits. Twenty-two host genes involved in transcriptional regulation related to metal ion binding (including potassium, sodium, calcium, zinc, iron) were positively correlated with a rumen bacterial cluster 1 composed of Alloprevotella , Paludibacter , Arcobacter , Lactobacillus , Bilophila , etc. Therefore, these studies help us to understand the interaction between rumen host and microorganisms in yaks at different ages, and further provide a reliable theoretical basis for the development of feed and mineral element supplementation for yaks at different ages.

Tick-borne diseases (TBDs) can cause serious economic losses and are very important to animal and public health. To date, research on TBDs has been limited in Qinghai-Tibet Plateau, China. This epidemiological investigation was conducted to evaluate the distribution and risk factors of Anaplasma spp. and Ehrlichia chaffeensis in livestock in Qinghai. A total of 566 blood samples, including 330 yaks ( Bos grunniens ) and 236 Tibetan sheep ( Ovis aries ) were screened. Results showed that A. bovis (33.3%, 110/330) and A. phagocytophilum (29.4%, 97/330) were most prevalent in yaks, followed by A. ovis (1.2%, 4/330), A. capra (0.6%, 2/330), and E. chaffeensis (0.6%, 2/330). While A. ovis (80.9%, 191/236) and A. bovis (5.1%, 12/236) infection was identified in Tibetan sheep. To our knowledge, it is the first time that A. capra and E. chaffeensis have been detected in yaks in China. Apart from that, we also found that co-infection of A. bovis and A. phagocytophilum is common in yaks (28.2%, 93/330). For triple co-infection, two yaks were infected with A. bovis, A. phagocytophilum , and A. capra , and two yaks were infected with A. bovis, A. phagocytophilum , and E. chaffeensis . Risk analysis shows that infection with A. bovis, A. phagocytophilum , and A. ovis was related to region and altitude. This study provides new data on the prevalence of Anaplasma spp. and E. chaffeensis in Qinghai, China, which may help to develop new strategies for active responding to these pathogens., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Wang, Zhang, Han, Li, Wang, Yuan, Zhang, Yang, Zhang, Sun, Chen, Han and He.)

Based on the CT data, a medical treatment FE model of hip joint prosthesis with stepped stem was rebuilt according the anatomy of the hip joint. Under the loads of 1.5 times standard body weight (70kg), the mechanical behavior of the treatment model was calculated, and the influence of step structure and distribution for stepped stem on femur stress and stability of total hip replacement were analyzed by three-dimensional finite element analysis (3D-FEA). The results show that the step structure changs the bone stress transmission on the interface of stepped stem and femur, and benefits to reduce stress-shielding in the femur. For the same distribution of step, the reduction of stress-shielding for raised stepped stem is better than that for concave stepped stem. The raised stepped stem of which the steps is distributed one of third part of the stem is of the best effect of reduction of stress shielding in all of the analysis models, and is a beneficial mechanical design to relieves osteoporosis or osteopenia of femur caused by stress-shielding and improve the reliability of it in clinic.

Hydroxyapatite coatings were deposited on Ti-6Al-4V substrates by a novel plasma spraying process, the liquid precursor plasma spraying (LPPS) process. X-ray diffraction results showed that the coatings obtained by the LPPS process were mainly composed of hydroxyapatite. The LPPS process also showed excellent control on the coating microstructure, and both nearly fully dense and highly porous hydroxyapatite coatings were obtained by simply adjusting the solid content of the hydroxyapatite liquid precursor. Scanning electron microscope observations indicated that the porous hydroxyapatite coatings had pore size in the range of 10-200 µm and an average porosity of 48.26 ± 0.10%. The osteoblastic cell responses to the dense and porous hydroxyapatite coatings were evaluated with human osteoblastic cell MG-63, in respect of the cell morphology, proliferation and differentiation, with the hydroxyapatite coatings deposited by the atmospheric plasma spraying (APS) process as control. The cell experiment results indicated that the heat-treated LPPS coatings with a porous structure showed the best cell proliferation and differentiation among all the hydroxyapatite coatings. Our results suggest that the LPPS process is a promising plasma spraying technique for fabricating hydroxyapatite coatings with a controllable microstructure, which has great potential in bone repair and replacement applications.

A simple electrodeposition method is presented for the preparing of collagen nanofilms (EAT) on anodic oxidized titanium surfaces (AT). The nanofilms were observed by scanning electron microscopy and atomic force microscopy. Functional TiOx layers with anionic groups of --PO(4), --SO(4) and --OH were investigated on the AT surface by X-ray photoelectron spectroscopy; X-ray diffraction results indicated that the AT surface was composed mainly of anatase and rutile. The bioactive electrodeposited TiOx layers on the AT surface showed lower water contact angles and higher surface energy than pure titanium surfaces (CT) and displayed higher collagen molecule immobilization.

A fast and effective electrochemical method was developed to make a dense calcium phosphate films on titanium and stainless steel for hard tissue replacement. The surfaces of titanium and stainless steel were cathodically treated in an electrochemical cell. By controlling the treatment parameters, a film of 100-nm thickness was deposited on the metal surface in several minutes. The thin film was amorphous calcium phosphate containing octacalcium phosphate nuclei, and also dense and ductile. The treated metals were able to induce bioactive calcium phosphate deposition after immersion in simulated body fluid (SBF) for only 1 and 2 days. In vivo study was conducted by implanting the treated specimens of titanium and stainless steel in dog's femur cavity. The treated metallic surfaces showed good ability of osteoconduction. This surface treatment method can be potentially used to enhance bioactivity of any type of metallic surfaces.

Two types of glass ceramics with different porosities and crystallinities were produced by sintering 45S5 Bioglass particulates. The in vivo bioactive response of the glass ceramics was evaluated by implanting them in rabbit muscle sites. After six weeks implantation, silicon-rich networks were observed on both types of ceramics, but the number of networks was much larger in the poorly crystallized dense ceramics than in the well crystallized porous ones. This indicated that the crystallization of glass ceramics retarded the formation of networks on surfaces. Apatite precipitation was found in pore areas of the porous ceramics, but not on the dense ones, suggesting that porosity was necessary for glass ceramics to induce apatite precipitation in a rabbit model.

Using the CT data, we have constructed the finite element models of human femur distally amputated at high-position, middle-position and low-position, along with distally osseointegrated implant under the maximal load during a normal walking cycle. Results of finite element analysis revealed: the maximal stress of implant is produced near the exit of the amputated limb, where the fatigue breakpoint caused by cyclic stress would take place. With the ascending of truncated position, the peri-implant interfacial stress of bone increases. There is severe stress-shielding at the bone-implant interface, and there is concentration of stress at the end of implant and at the 3/4 point of femur, which would lead to bone loss and bone resorption and would shorten the longevity of implant. The results also showed that the curvature of natural bone has notable effect on the stress distribution, which should not be neglected. These data may provide reliable reference for the design and research of osseointegarted artificial limb.

Formation of calcium phosphate (Ca-P) on various bioceramic surfaces in simulated body fluid (SBF) and in rabbit muscle sites was investigated. The bioceramics were sintered porous solids, including bioglass, glass-ceramics, hydroxyapatite, alpha-tricalcium phosphate and beta-tricalcium phosphate. The ability of inducing Ca-P formation was compared among the bioceramics. The Ca-P crystal structures were identified using single-crystal diffraction patterns in transmission electron microscopy. The examination results show that ability of inducing Ca-P formation in SBF was similar among bioceramics, but considerably varied among bioceramics in vivo. Sintered beta-tricalcium phosphate exhibited a poor ability of inducing Ca-P formation both in vitro and in vivo. Octacalcium phosphate (OCP) formed on the surfaces of bioglass, A-W, hydroxyapatite and alpha-tricalcium phosphate in vitro and in vivo. Apatite formation in physiological environments cannot be confirmed as a common feature of bioceramics.

Bone formation on hydroxyapatite (HA) coating in the presence of gaps is important for clinical application. Pure Ti and hydroxyapatite coated by plasma sprayed samples were implanted in dog respectively. The implants were surrounded by gaps of 2 mm, and the follow-up period was 12 weeks. Histological examination and histomorphometry revealed that gaps could be bridged by bone provided the hydroxyapatite coating was applied, and that pure Ti implants were surrounded by fibrous tissue with no bone contact at all.

The dissolution and mineralization behavior of HA coatings are two of the main factors governing the bioactivity of coatings. After different post treatment operators, the plasma-sprayed HA coatings have different characteristics, including different chemical composition, crystallinity, crystallite size and dissolution behavior. In this study, HA coatings were characterized by X-ray diffraction, scanning electron microscope, and Fourier transform infrared spectra before and after immersion in simulated body fluid (SBF). When immersed in SBF, both dissolution and precipitation occurred at the same time, but the kinetics of dissolution was quite different from that of precipitation. The former was dominated by ion exchange, while the latter was controlled by the ion concentration product and the solubility of the particles. Therefore, the dissolution behaviors of phosphate ions partly depended on the dissolution behaviors of calcium ions. With the increase of ions concentration in solution by dissolution, more nucleation sites appeared on the surface of coatings. Crystalline grains gradually grew up on the nucleation sites and developed into biomineral layers. The biomineral layers were the results of the precipitation of the ions in the solution; and the carbonates partially substituted phosphates to form bone-like apatite. The different dissolution characters resulted in quite different morphology of the biomineral layers: the coatings with low solubility induced biomineral layers of large grains; on the contrary, the biomineral layers of network structure were observed on the more soluble coatings.

This study focuses on phase identification of precipitation on bioactive calcium phosphate (BCP) surfaces in vitro and in vivo. The BCP used in this study consisted of 70 wt% hydroxyapatite (HA) and 30 wt% beta-tricalcium phosphate. Single crystalline precipitates of calcium phosphates on porous BCP bioceramics obtained after immersion in dynamic simulated body fluid (SBF) and after implantation in pig muscle were examined using electron diffraction in transmission electron microscope. The crystals formed in vitro in dynamic SBF were identified as octacalcium phosphate (OCP), instead of apatite. Most of the precipitated crystals in vivo samples had an HA structure; while OCP and dicalcium phosphate dihydrate were also identified. The evidence from single diffraction patterns indicates that apatite formation on bioactive ceramics is a complicated process, particularly in physiological environments where formation might include a transient stage of intermediate phases.

The torsional strength of plasma sprayed hydroxyapatite (HA) coatings was studied under static and cyclic loading. The torsional shear tests were conducted in a frustum test device developed in this laboratory, which adapted to various coating thicknesses. The interfacial fatigue resistance was measured in terms of interfacial fatigue strength defined as the average maximum stress (tau(fmax)). A staircase fatigue method was employed to determine the interfacial fatigue strength; this method resolved the uncertainty in detecting coating failure during torsion fatigue. The values for coating shear strength and shear fatigue strength obtained from the torsional tests did not differ from those obtained by previous tensional shear tests in this laboratory. The fatigue strength of one million cycles was about 35% lower than static shear strength. This finding might be used for estimating fatigue life span without cyclic loading tests.

Bone-like apatite formation on the surface of calcium phosphate ceramics has been believed to be necessary for new bone to grow on the ceramics and to be related to the osteoinductivity of the material. The research of bone-like apatite formation is a great help to understanding the mechanism of osteoinduction. Synthetic porous calcium phosphate ceramics (HA/TCP = 70/30) were implanted intramuscularly in pigs, dogs, rabbits and rats to make a comparative study of the bone-like apatite formation onto the porous HA/TCP ceramics in different animals. Specimens were harvested at 14 days after implantation. Samples were detected for the surface morphology with SEM. The chemical composition of the sample surface after implantation was analyzed with reflection infrared (R-IR). Obvious bone-like apatite formation could be detected in the sections of porous specimens harvested from all animals after 14 days intramuscular implantation. Crystal deposition could be only observed on the surface of the concave regions of the samples collected from dogs, rabbits and rat. On the contrary, evenly distributed flake-shaped crystal could be found on the pore surface and also on the outer surface of the materials implanted in pigs. The morphology of bone-like apatite in pigs was different from that in the others animals. Bone-like apatite was not observed in dense specimen implanted intramuscularly. Bone-like apatite formed faster on specimens implanted in rabbit than that in other animals. This formation sequence is different from the sequence of osteoinductivity of biphasic calcium phosphate ceramics implanted in these animals. The results demonstrated that the formation of bone-like apatite on materials is a prerequisite condition to their osteoinduction but other factors also play important roles in osteoinduction.

This study aimed at investigating the influence of the flow rate of simulated body fluid (SBF) (2 ml/100 ml.min) of body fluid in skeletal muscle upon the formation of bone-like apatite on porous calcium phosphate ceramics. The in vitro immersion experiment in SBF flowing at normal physiological rate is referred to as dynamic SBF. The results showed that bone-like apatite could only formed in the pores of porous calcium phosphate when SBF flow at physiological rate (2 ml/100 ml.min) of body fluid in skeletal muscle. At the same time, bone-like apatite could form both in the pores and on the surface of the samples if the flowing physiological solution is 1.5 SBF. When the flowing speed of SBF is higher than normal physiological speed (10 ml/100 ml.min), no bone-like apatite could be detected both on the surface and in the pores of the materials. This result is in concordance with animal experiments. The dynamic SBF simulates the biological environment of bone-like apatite formation in body better than static SBF (SBF does not flow). This method is very useful for the research of the mechanism of bonelike apatite formation, which is the key step of bone growth on biomaterials, and can be used as an effective approach to investigate mechanism of the osteoinduction of calcium phosphate in nonosseous tissues in vivo.

Highly crystalline feedstock hydroxyapatite (HA) particles with irregular shapes were spheroidized by plasma spraying them onto the surface of ice blocks or into water. The spherical Ca-P particles thus produced contained various amounts of the amorphous phase which were controlled by the stand-off distance between the spray nozzle and the surface of ice blocks or waiter. The smooth surface morphology without cracks of spherical Ca-P particles indicated that there were very low thermal stresses in these particles. Plasma-sprayed Ca-P particles were highly bioactive due to their amorphous component and hence quickly induced the formation of bone-like apatite on their surfaces after they were immersed in an acellular simulated body fluid at 36.5 C. Bone-like apatite nucleated on dissolved surface (due to the amorphous phase) of individual Ca-P particles and grew to coalesce between neighboring Ca-P particles thus forming an integrated apatite plate. Bioactive and biodegradable composite scaffolds were produced by incorporating plasma-spray ed Ca-P particles into a degradable polymer. In vitro experiments showed that plasma-sprayed Ca-P particles enhanced the formation of bone-like apatite on the pore surface of Ca-P/PLLA composite scaffolds.

Bone-like apatite formation on the surface of calcium phosphate ceramics has been believed to be the prerequisite of new bone growth on ceramics and to be related to the osteoinductivity of the material. The research of the factors effecting bone-like apatite formation is a great help in understanding the mechanism of osteoinduction. This paper is aimed to a comparative study of in vitro formation of bone-like apatite on the surface of dense and rough calcium phosphate ceramics with SBF flowing at different rates. The results showed that the rough surface was beneficial to the formation of bone-like apatite, and the apatite formed faster in 1.5 SBF than in SBF. Rough surface, namely, larger surface area, increased the dissolution of Ca2+ and HPO4(2-) and higher concentration of Ca2+ and HPO4(2-) ions of SBF and was in turn advantageous to the accumulation of Ca2+, HPO4(2-), PO4(3-) near the ceramic surface. Local supersaturating concentration of Ca2+, HPO4(2-), PO4(3-) near sample surface was essential to nucleation of apatite on the surface of sample.

A Ca-deficient carbonate apatite coating on titanium was prepared by pre-calcifying titanium in a saturated Ca(OH)2 solution and then immersing in a supersaturated calcium phosphate solution. The interaction of the protein with the apatite coating on titanium was investigated by scanning electron microscopy with X-ray energy dispersion spectroscopy. X-ray photoelectron spectroscopy, X-ray diffraction and Fourier transform infrared spectroscopy. During immersion of the coating in bovine serum albumin (BSA) solution, accompanied by an adsorption of BSA onto the coating, calcium and phosphate ions dissolved and reprecipitated, resulting in the formation of the coating containing BSA from the surface to subsurface layers. The adsorption modified the structure and morphology of the apatite coating on titanium and changed the protein configuration. It was also found that the protein chemically adsorbed onto surfaces containing calcium or phosphorus, showed that both Ca and P on the apatite coating were the binding sites with protein. The BSA adsorption onto the coating involved several elements and groups. In this process. Ca played an essential role, and the interaction of Ca on the apatite coating with the protein stimulated the bond of the protein at P sites.