Bone Elements Research Articles

Patrones ganaderos e inferencias culturales en la ciudad islámica de Qartayanna (Cartagena, España)

This paper presents the results of the faunal analysis of the bone remains recovered in the Islamic suburb located on the Roman theater of Cartagena (Murcia), with a broad chronological overview (ss. X-XIII). Thanks to the analysis of 6,940 bone elements recovered in dumps associated with houses, the consumption patterns and livestock strategies of a city that is recovering its importance from the 10th century, within the Islamic orbit, are inferred, which will leave a mark on consumption patterns associated with identity and cultural issues. In this way, the progressive loss of the ruralized image of the previous period (Byzantine era) is observed and progress is made towards a market economy typical of a big city. This work emphasizes the potential of archaeofaunistic studies to determine cultural issues.

Facile synthesis of in situ bismuth-doped calcium phosphate nanocomposite integrated injectable biopolymer hydrogel slurry for bone regeneration

The bionics of natural bone structures plays an essential role in the selection of materials for bone tissue engineering. Although the content of trace metallic elements in bone is low, they have significant effects on the process of bone growth and metabolism. Up to now, the applications of “green” heavy metals in bone regeneration are limited. Herein, in this study, we present a straightforward one-pot strategy for the synthesis of in situ bismuth-doped amorphous calcium phosphate nanocomposites (RBCP), effectively integrating the beneficial properties of each component. The characterization of these products can be readily optimized by adjusting reaction parameters. Our in vitro studies show that under coordination of each component, the RBCP biomaterial demonstrates distinguished biocompatibility and significantly accelerates vascular pattern formation within just 4 h by stimulating the expression of angiogenesis-related genes in human umbilical vein endothelial cells (HUVECs). In vivo experiments indicate that the incorporation of bismuth effectively enhances bone regeneration and osseointegration in a rat femur defect model. In conclusion, the as-prepared RBCP biomaterials hold promising prospects for treating segmental bone defects, owing to the facile, cost-effective, and eco-friendly preparation process, along with their remarkable capabilities.

INAA of bone remains of Bohemian Duke John of Görlitz: an attempt to explain his sudden death at the age of twenty-five years

AbstractInstrumental neutron activation analysis (INAA) was employed to assay 32 minor and trace elements in bone of Bohemian Duke John of Görlitz (1370–1396) who suddenly died at the age 25 years for unknown reasons. Recently, histological examination of his illium bone was carried out, accompanied by histochemical staining reactions to learn about his health status. The INAA results disproved an elevated Al content indicated by the staining reaction with aluminon, but revealed elevated levels of Mn, As, Sb, and especially of Ag compared with literature values. The results are discussed in terms of toxicity of the above elements, especially whether their elevated levels could be the reason for Duke´s sudden death.

Ichnological records associated with dermestid beetles in dinosaur bones from Lala's Place (Maastrichtian), Ramos Arizpe, Coahuila, Mexico, and their taphonomic implications

We analyzed the ichnological record of hadrosaur remains from the dinosaur quarry CLP-3, Lala's Place, Ramos Arizpe, Coahuila, where taphonomic research is ongoing. These fossils have been determined to stratigraphically belong to the Cerro del Pueblo Formation, deposited in a deltaic floodplain environment. The Lala's Place quarries have been determined to belong to the early Maastrichtian (69 ± 5 Ma) through U/Pb detrital zircon dating. Thirteen trace fossil morphotypes were identified in six bone elements, interpreted to belong to a single individual. These traces were identified to belong to the ichnospecies Cuniculichnus seilacheri, cf. Cubiculum cooperi, Cubiculum atsintli. A new ichnospecies, Cubiculum subcorticalis n. isp., characterized by a composite feeding-pupation trace with subcortical chambers, is also described. Based on these findings, temporal range of the previously described ichnospecies is expanded to the Maastrichtian stage in the Cerro del Pueblo Formation. Previous work has reported these ichnospecies and associated them with dermestid beetles; this work also associates these traces with dermestids through morphological analyses and using for the first time the novel Usefulness in Identification and Differentiation (UID) index, recently proposed for this taxon. These traces indicate that the carcass was exposed to a subaerial environment for at least 20–30 days, reaching a dry stage in which dermestid adults fed, reproduced, and oviposited. Larvae produced these traces by excavating chambers to avoid cannibalism by other larvae.

X-ray diagnostics diseases of the temporomandibular joints

TMJ diseases, the occurrence of which can be caused by numerous factors, are a common pathology among the population. The purpose of the study was to research the characteristics of x-ray manifestations and the informativeness of x-ray techniques in the x-ray diagnosis of TMJ diseases. 645 X-ray images of 344 patients aged 18 to 65 years were analyzed. It has been established that the X-ray picture of most TMJ diseases is characterized by the presence of functional changes or a combination of functional and organic manifestations. The most common pathology is dysfunctional disorders of the TMJ. It was concluded that the primary X-ray diagnosis of TMJ diseases is advisable to carry out using orthopantomographs, which allow examining the TMJ in the lateral projection according to a special program with the patient’s mouth open and closed. The use of computed tomography makes it possible to identify not only functional abnormalities, but also early manifestations of organic changes in the bone elements of the TMJ on a series of tomographic sections in different planes.

Kinetic methods used in the postoperative recovery of a patient diagnosed with a puncture wound and foreign body retention in the middle third of the posterior face of the left forearm

Due to its superficial positioning, the muscle is more frequently exposed to trauma than bone or joint elements. Muscle injuries can occur either as a result of external forces, such as a traumatic agent, or internal forces that affect muscle function. This paper presents a patient diagnosed with a puncture wound and retention of a for-eign body in the middle third of the posterior aspect of the left forearm, with its extraction following three surgical interventions. This type of injury presents an increased risk of af-fecting daily life activities. The patient was functionally assessed post-operatively upon inclusion in the rehabili-tation program, during the program to observe progress, and at the end of kinetic treat-ment. The rehabilitation plan must be preceded by an adequate assessment, followed by setting goals according to the patient's needs and test results. Consequently, the patient rigorously followed the initial kinetic exercise plan established by the physiotherapist, leading to an improvement in muscle strength, joint mobility, and motor control. This re-sulted in an increase in the quality of life and social-professional reintegration. Keywords: Osteoarthritis, knee, ultrasonography, cartilage, pain.

Functional modularity and mechanical stress shape plastic responses during fish development.

The adaptive potential of plastic phenotypes relies on combined developmental responses. We investigated how manipulation of developmental conditions related to foraging mode in the fish Megaleporinus macrocephalus induces plastic responses at different levels: (a) functional modularity of skull bones, (b) biomechanical properties of the chondrocranium using finite element models, (c) bmp4 expression levels, used as a proxy for molecular pathways involved in bone responses to mechanical load. We identified new modules in experimental groups, suggesting increased integration in specific head bone elements associated with the development of subterminal and upturned mouths, which are major features of Megaleporinus plastic morphotypes released in the lab. Plastic responses in head shape involved differences in the magnitude of mechanical stress, which seem restricted to certain chondrocranium regions. Three bones represent a "mechanical unit" related to changes in mouth position induced by foraging mode, suggesting that functional modularity might be enhanced by the way specific regions respond to mechanical load. Differences in bmp4 expression levels between plastic morphotypes indicate associations between molecular signaling pathways and biomechanical responses to load. Our results offer a multilevel perspective of epigenetic factors involved in plastic responses, expanding our knowledge about mechanisms of developmental plasticity that originate novel complex phenotypes.

Evaluation of a New DNA Extraction Method on Challenging Bone Samples Recovered from a WWII Mass Grave.

Bones and teeth represent a common finding in ancient DNA studies and in forensic casework, even after a long burial. Genetic typing is the gold standard for the personal identification of skeletal remains, but there are two main factors involved in the successful DNA typing of such samples: (1) the set-up of an efficient DNA extraction method; (2) the identification of the most suitable skeletal element for the downstream genetic analyses. In this paper, a protocol based on the processing of 0.5 g of bone powder decalcified using Na2EDTA proved to be suitable for a semi-automated DNA extraction workflow using the Maxwell® FSC DNA IQ™ Casework Kit (Promega, Madison, WI, USA). The performance of this method in terms of DNA recovery and quality was compared with a full demineralisation extraction protocol based on Qiagen technology and kits. No statistically significant differences were scored according to the DNA recovery and DNA degradation index (p-values ≥ 0.176; r ≥ 0.907). This new DNA extraction protocol was applied to 88 bone samples (41 femurs, 19 petrous bones, 12 metacarpals and 16 molars) allegedly belonging to 27 World War II Italian soldiers found in a mass grave on the isle of Cres (Croatia). The results of the qPCR performed by the Quantifiler Human DNA Quantification kit showed values above the lowest Limit of Quantification (lLOQ; 23 pg/µL) for all petrous bones, whereas other bone types showed, in most cases, lower amounts of DNA. Replicate STR-CE analyses showed successful typing (that is, >12 markers) in all tests on the petrous bones, followed by the metacarpals (83.3%), femurs (52.2%) and teeth (20.0%). Full profiles (22/22 autosomal markers) were achieved mainly in the petrous bones (84.2%), followed by the metacarpals (41.7%). Stochastic amplification artefacts such as drop-outs or drop-ins occurred with a frequency of 1.9% in the petrous bones, whereas they were higher when the DNA recovered from other bone elements was amplified (up to 13.9% in the femurs). Overall, the results of this study confirm that petrous bone outperforms other bone elements in terms of the quantity and quality of the recovered DNA; for this reason, if available, it should always be preferred for genetic testing. In addition, our results highlight the need for accurate planning of the DVI operation, which should be carried out by a multi-disciplinary team, and the tricky issue of identifying other suitable skeletal elements for genetic testing. Overall, the results presented in this paper support the need to adopt preanalytical strategies positively related to the successful genetic testing of aged skeletal remains in order to reduce costs and the time of analysis.

Analysis of load distribution after transpedicular stabilization of burst fractures in the thoracolumbar junction

Background. In the structure of all traumatic spine injuries, the thoracolumbar junction is predominant, accounting for over 53 % of all vertebral fractures. One of the most clinically significant types of injuries in this area are burst fractures. The purpose was to study the stress-strain state of the thoracolumbar spine model with a burst fracture of the Th12 vertebra in various transpedicular fixation options under compression load. Materials and methods. The study developed and investigated a finite element model of the thoracolumbar spine with a burst fracture of the Th12 vertebra. The burst fracture was modeled by dividing the vertebral body of the Th12 into several planes, transforming it into separate fragments. The gaps between these fragments were filled with a material that simulated the interfragmentary regenerate. Variants of transpedicular stabilization using different types of screws, mono- or bicortical, and with or without cross-links, were examined. The model was analyzed under compression load. Results. The maximum level of stress among the bone structures directly involved in fixation was registered in the L2 vertebral body. It amounted to 19.9, 15.6, 19.4, and 15.1 MPa, respectively, for models with monocortical screws without cross-links, bicortical screws without cross-links, monocortical screws with cross-links, bicortical screws with cross-links. Simultaneously, the zone of screw entry into the arch of this vertebra shows values of 10.1, 15, 10.2, and 14.3 MPa for these models, respectively. Peak loads on the metal structure elements are observed on the rods, amounting to 212.5, 159.6, 203.7, 142.8 MPa, respectively, for the considered models. Conclusions. The results of the study showed that under the influence of compression load when modeling a burst fracture of the thoracolumbar junction, the use of long screws leads to a reduction in stress levels, both in the elements of the metal structure and in the bone elements of the model, while the use of cross-links has a negligible effect.

Fishboneviz: Enhancing the availability of zooarchaeological fish reference collections through an open access 3D database

Fish remains are a common component of coastal and inland archaeological assemblages from Australia and the Pacific Islands. Physical reference collections are the primary tool that researchers use to taxonomically identify fish bones but given the high biodiversity of fishes in this region, collections are frequently not complete at the genus- and species-level. Adjunct resources, such as online photograph repositories of fish bone reference collections and illustrated technical guides, provide useful supplementary aids. However, such 2D photographs and illustrations offer fixed perspectives of the bone and do not allow for ready manipulation and detailed examination of the specimen. Here, we introduce Fishboneviz, the first open access 3D fish bone reference collection, which was developed to reduce inequitable access to physical reference collections in line with the FAIR principles of data management (findable, accessible, interoperable, reusable). A ‘best-practice’ methodology was established to facilitate fast and effective segmentation (i.e. isolate regions of interest such as elements) of fish Computed Tomography (CT) scans. This way, fish bone elements of interest were segmented to allow digital manipulation and viewing of the complete element. To examine the effectiveness of the approach, image segmentation procedures were applied to a representative sample of 10 bone elements per fish: dentary, premaxilla, maxilla, articular, quadrate, hyomandibular, opercle, preopercle, last precaudal vertebra, and first caudal vertebra. For species within the family Labridae, the three pharyngeal grinding plates were also segmented. These elements were selected as they represent different regions of the skeleton, variable morphologies, and commonly recovered elements from archaeological sites. To date, the collection contains the skeletal elements of 26 fish species (18 families). In the future, it is hoped that the collection will be further expanded by a broader network of interested collaborators to ensure it grows according to the changing needs of research and teaching communities.

Archaeological evidence of rodent consumption in North Africa: The Middle Stone Age of the rock shelter Ifri n'ammar in northeastern Morocco

This study presents undeniable evidence of anthropogenic exploitation of small mammals in Ifri n'Ammar rock shelter, located in the northeast of Morocco. Among the rodent species found at this site, Ctenodactylus gundi predominates in the assemblage of small mammals between approximately 130 ± 8 ka and 83 ± 6 ka. The taphonomic analysis of the fossil remains of this species, discovered alongside other components of the archaeological assemblage, clearly indicates that during the Middle Stone Age (MSA), humans consumed this species. Therefore, they are considered the main agents responsible for the accumulation of dental and postcranial remains of this species recorded in the shelter. Since the early Upper Pleistocene, bone elements bearing cut-marks and burn traces unequivocally attest to the consumption of this rodent by the hunter-gatherers at the Ifri n'Ammar rock shelter. Our findings regarding the exploitation of this species by humans in the northeastern region of Morocco are corroborated by ethnographic data, demonstrating that North African populations captured and consumed this large-sized rodent until the last century. The species Ctenodactylus gundi is known for its diurnal activity, gregarious and social habits, as well as its preference for rocky and arid environments.

Micromechanical modelling of transverse fracture behaviour of lamellar bone using a phase-field damage model: The role of non-collagenous proteins and mineralised collagen fibrils

At the tissue-scale and above, there are now well-established structure-property relationships that provide good approximations of the biomechanical performance of bone through, for example, power-law relationships that relate tissue mineral density to elastic properties. However, below the tissue-level, the individual role of the constituents becomes prominent and these simple relationships tend to break down, with more detailed theoretical and computational models are required to describe the mechanical response. In this study, a two-dimensional micromechanics damage-based representative volume element (RVE) of lamellar bone was developed, which included a novel implementation of a phase-field damage model to describe the behaviour of non-collagenous proteins at mineral-mineral and mineral-fibril interface regions. It was found that, while the stiffness of the tissue was governed by the relative proportion of extra-fibrillar mineral and mineralised collagen fibrils, the strength and toughness of the tissue in transverse direction relied on the interactions occurring at mineral-mineral and mineral-fibril interfaces, highlighting the prominence of non-collagenous proteins in determine fracture-based processes at this scale. While fractures tended to initiate in mineral rich areas of the extra-fibrillar mineral matrix, it was found that the presence of mineralised collagen fibrils at low density did not provide a substantial contribution to crack propagation behaviour under transverse loading. However, at physiological volume fraction (VfMCF=50%), different scenarios could arise depending on the relative strength value of the interphase around the MCFs (σfInterphaseMCF) to the interphase between individual minerals (σfInterphaseHA): (i) When γ=σfInterphaseMCFσfInterphaseHA<1, MCFs appear to facilitate crack propagation with MCF-mineral debonding being the dominant failure mode; (ii) once γ>1, the MCFs hinder the microcracks, leading to inhibition of crack propagation, which can be regarded as an energy dissipation mechanism. The effective fracture properties of the tissue also experience a sudden increase in fracture work density (J-integral) once the crack is arrested by MCFs or severely deflected. Collectively, the predicted behaviour of the model compared well to those reported through experimental and computational methods, highlighting its potential to provide further understanding into the mechanistic response of bone ultrastructure alterations related to the structural and compositional changes resulting from disease and aging.

Mechanobiochemical bone remodelling around an uncemented acetabular component: influence of bone orthotropy.

Mechanical loosening of an implant is often caused by bone resorption, owing to stress/strain shielding. Adaptive bone remodelling elucidates the response of bone tissue to alterations in mechanical and biochemical environments. This study aims to propose a novel framework of bone remodelling based on the combined effects of bone orthotropy and mechanobiochemical stimulus. The proposed remodelling framework was employed in the finite element model of an implanted hemipelvis to predict evolutionary changes in bone density and associated orthotropic bone material properties. In order to account for variations in load transfer during common daily activities, several musculoskeletal loading conditions of hip joint corresponding to sitting down/up, stairs ascend/descend and normal walking were considered. The bone remodelling predictions were compared with those of isotropic strain energy density (SED)-based, isotropic mechanobiochemical and orthotropic strain-based bone remodelling formulations. Although similar trends of bone resorption were predicted by orthotropic mechanobiochemical (MBC) and orthotropic strain-based models across implanted acetabulum, more volume (10-20%) of bone elements was subjected to bone resorption for the orthotropic MBC model. Higher bone resorption (75-85%) was predicted by the orthotropic strain-based and orthotropic MBC models compared to the isotropic MBC and SED-based models. Higher bone apposition (35-160%) across the implanted acetabulum was predicted by the isotropic MBC model, compared to the SED-based model. The remodelling predictions indicated that a reduction in estrogen level might lead to an increase in bone resorption. The study highlighted the importance of including mechanobiochemical stimulus and bone anisotropy to predict bone remodelling adequately.

Comparison between cervical vertebrae of man and of the domestic animals

Anatomy is the science that studies the form, architecture and structure of living beings, and the modality that explores the morphological differences between species is called comparative anatomy. Among the bone structures that make up the axial skeleton of individuals, the cervical vertebrae stand out, considered odd and irregular bones. Given the relevance of cervical vertebrae, the objective of the present study was to compare such bone elements in humans and domestic animals (dogs, horses and cattle) and, nevertheless, highlight the structural similarities in these different species in terms of quantities, functions and formats in resulting from bone accidents. For this, skeletons and individual anatomical pieces from the Human and Veterinary Anatomy Laboratory of the University of Franca (UNIFRAN - Franca, SP) were used, as well as anatomy books renowned in this area of ​​specialty and scientific articles. The results were presented in a descriptive way. As for quantity, humans have seven cervical vertebrae, just like dogs, horses and cattle. In all species, the cervical vertebrae support the neck, providing movement of the head and protection of the cervical spinal cord. Regarding shape, the first (atlas) and second (axis) cervical vertebrae are atypical in all species. The atlas has an arched body, containing the dorsal and ventral tubercle; furthermore, the transverse process is modified (wing of the atlas) with the alar foramen and lateral vertebral foramen. The caudal articular surface of the atlas (fovea dentis) articulates with the odontoid process of the axis. Cattle do not have a transverse foramen and, in no species, does the spinous process appear in the atlas. The axis had a rod-shaped odontoid process in dogs, concave in cattle and pointed in other species, in addition to an elongated spinous process. The other cervical vertebrae are typical, composed of a vertebral body (with head of the vertebra and vertebral fossa), vertebral arch (participates in the formation of the vertebral foramen), vertebral foramen (houses the spinal cord) and spinous processes (poorly developed), transverse (well developed, containing the transverse foramen) and cranial and caudal articular (flat surfaces). In all species, the seventh cervical vertebra is modified, presenting a long spinous process and reduction or absence of the transverse foramen; furthermore, in horses, the spinous process was detected only in this vertebra. In humans, dogs, horses and cattle, the seventh cervical vertebra has a pair of caudal costal facets for articulation with the first pair of ribs. Given the results obtained, it is accepted that the anatomical morphological similarities and differences between the cervical vertebrae may be related to the functional, evolutionary and postural aspects of the different species studied.

Zooming in on amphibians: Which is the smallest vertebrate in the world?

AbstractDuring the last decades several miniaturized frogs have been described from different parts of the world. Those frogs, measuring less than 25 mm, show similar miniaturization features as the loss of phalanges in both the anterior and posterior limbs and the reduction of bone elements. However, there seems to be a limit regarding the minimum size of frogs and here we wanted to find an answer to the question: which is the smallest amphibian in the world? In 2019, an endemic species of toad known only from two localities in southern Bahia, Brazil, was studied. When we compared the size of adult representatives of this species with those of other species discovered in various parts of the world in the last decade, we observed that individuals of Brachycephalus pulex are the amphibians with the smallest total length recorded, thus qualifying them to bear the title of the tiniest anuran amphibian, and also tiniest vertebrate in the world.

Early Cannon Development in Females of the "Sanmartinero" Creole Bovine Breed.

The variation in the dimensions of the body of living beings in relation to their size, function, or shape is known as allometry. Allometry studies allow the analysis of the function of body structures and their relationship with the performance and survival of breeds and species. The aim of this study was to describe the ontogenetic characteristics of the weight of certain bone elements of the Sanmartinero creole bovine breed, from an early age (6 months) until maturity. A total of 79 females of the Sanmartinero creole bovine breed with an age range of 0.5 to 10 years were studied. Body measurements were obtained individually using standard procedures: cannon perimeter, thoracic perimeter, body length, withers height, and body weight. Functional and production indices were obtained for animals aged more than 3 years (n = 53): corporal index, anamorphosis index, dactylo thoracic index, and the relative thickness of the cannon. The correlation between body weight and the cannon perimeter showed no trend towards a plateau. In the Sanmartinero creole bovine, therefore, a very early development of the cannon perimeter is detected, which could lead to bone fragility in heavier animals. Therefore, data suggest little harmony with appendicular bone development, i.e., with less robust cannons which are those necessary to support body mass. It is suggested that in genetic improvement programs of the Sanmartinero creole bovine, the measurement of the cannon perimeter, the withers height, and the thoracic perimeter should be considered.

The Identification Potential of Atherosclerotic Calcifications in the Context of Forensic Anthropology.

Atherosclerosis is an inflammatory disease that, in its more developed stages, can lead to the calcification of fatty plaques on the walls of arteries, resulting in the appearance of new bone elements. It is a condition that has been studied and documented little in the context of paleopathology, especially in the framework of forensic anthropology. This article analyzed the skeletal remains of 71 individuals (35 females and 36 males) from the Luís Lopes Identified Collection of the National Museum of Natural History and Science in Lisbon, 31 of whom had an autopsy report. An attempt was made to ascertain whether these bone elements resulting from atherosclerotic calcification would resist cadaveric decomposition and whether they would be recoverable several years after burial, and a survey was carried out of their distribution according to sex and age, as well as their association with other pathologies, such as osteoporosis and cardiac and renal pathologies. An imaging analysis of an atherosclerotic plaque was also carried out to complement the macroscopic analysis and present other methods of identifying plaques. It was concluded that each atherosclerotic calcification has a unique profile, which can be useful for identification, especially in cases where the individual shows a severe condition. In terms of identification potential, the analysis of calcified atherosclerotic plaques can be useful, as they can corroborate or reject an identification. However, it always requires the existence of ante-mortem imaging exams and must always be used in addition to other identification methods. Regardless of the identification, these plaques are bone elements resulting from a pathology and should, therefore, be known and recognized by the scientific community.

High-Speed Centrifugation Efficiently Removes Immunogenic Elements in Osteochondral Allografts.

The current clinical pulse lavage technique for flushing fresh osteochondral allografts (OCAs) to remove immunogenic elements from the subchondral bone is ineffective. This study aimed to identify the optimal method for removing immunogenic elements from OCAs. We examined five methods for the physical removal of immunogenic elements from OCAs from the femoral condyle of porcine knees. We distributed the OCAs randomly into the following seven groups: (1) control, (2) saline, (3) ultrasound, (4) vortex vibration (VV), (5) low-pulse lavage (LPL), (6) high-pulse lavage (HPL), and (7) high-speed centrifugation (HSC). OCAs were evaluated using weight measurement, micro-computed tomography (micro-CT), macroscopic and histological evaluation, DNA quantification, and chondrocyte activity testing. Additionally, the subchondral bone was zoned to assess the bone marrow and nucleated cell contents. One-way ANOVA and paired two-tailed Student's t-test are used for statistical analysis. Histological evaluation and DNA quantification showed no significant reduction in marrow elements compared to the control group after the OCAs were treated with saline, ultrasound, or VV treatments; however, there was a significant reduction in marrow elements after LPL, HPL, and HSC treatments. Furthermore, HSC more effectively reduced the marrow elements of OCAs in the middle and deep zones compared with LPL (p < 0.0001) and HPL (p < 0.0001). Macroscopic evaluation revealed a significant reduction in blood, lipid, and marrow elements in the subchondral bone after HSC. Micro-CT, histological analyses, and chondrocyte viability results showed that HSC did not damage the subchondral bone and cartilage; however, LPL and HPL may damage the subchondral bone. HSC may play an important role in decreasing immunogenicity and therefore potentially increasing the success of OCA transplantation.

Finite element analysis of the cervical spine: dynamic characteristics and material property sensitivity study

The study aimed to investigate the dynamic characteristics of the cervical spine and determine the effect of the material properties of the cervical spinal components on it. A finite element model of the head-cervical spine was developed based on CT scan data, and the first six orders of modes (e.g. flexion-extension, lateral bending, and vertical, etc.) were verified by experimental and simulation studies. The material sensitivity study was conducted by varying elasticity modulus of cervical hard tissues (cortical bone, cancellous bone, endplates, and posterior elements) and soft tissues (intervertebral disc and ligaments). The results showed that increasing the elastic modulus of ligaments by 4 times increased the natural frequency by 77%, while increasing that of cancellous bone by 4 times only increased the natural frequency by 6%. In the axial mode, the cervical spine had not only axial deformation but also anterior-posterior deformation, with the largest deformation located at the intervertebral disc C6-C7. Decreasing the elastic modulus of a component in soft tissues by 80% increased modal displacement by up to 62%. The material properties of the intervertebral discs and ligaments had opposite effects on the modal displacement and deformation of the cervical spine. Low cervical discs were more susceptible to injury in a vertical vibration environment. Cervical spine dynamics were more sensitive to soft tissue material properties than to hard tissue material properties. Disc degeneration could reduce the range of vibratory motion of the cervical spine, thereby reducing the ability of the cervical spine to cushion head impacts.

Polar location of Teete dinosaur fauna (Eastern Siberia, Yakutia)

A few localities world wide are known to have remainsof dinosaurs andothervertebrate animalsthat livedin thepolarlatitude region during the Mesozoic era. The Teete locality in the Vilyui River Basin, Yakutia (Russia) is one of the few known dinosaur localities in the Northern Hemisphere. In 1988, 2002–2012 school children participated in asearch for Early Cretaceous dinosaurs and other vertebrates at the Teete locality, and teeth and bones were collected and briefly described.Additional vertebrate remains, including lizards, salamanders, choristoderes, and tritylodonts, were discovered in Early Cretaceous sediments in Yakutia, which expanded the number of known locations wherethese animals lived in polar regions. In 2017–2019 comprehensive paleontological studies were conducted in Teete,during which time fragmentary skeletal elements and teeth of various dinosaur groups, as wellas bone elements from other vertebrates, were collected using surface collection methods. This study also yielded new genera of Mesozoic mammaliforms,mammals,and salamanders.The presence of astem salamander, basalturtle, and other Jurassic relicts in the Early Cretaceous vertebrate fauna of Teete suggests that the area was a refugium for these animals during that time. Further study of the Teete locality is expected to lead to the description of new dinosaur and other vertebrate taxa, as wellas to theacquisitionof new data on the adaptation of these animals to circumpolar conditions.