Ibandronate Suppresses Changes in Apatite Orientation and Young's Modulus Caused by Estrogen Deficiency in Rat Vertebrae

Bone material quality is important for evaluating the mechanical integrity of diseased and/or medically treated bones. However, compared to the knowledge accumulated regarding changes in bone mass, our understanding of the quality of bone material is lacking. In this study, we clarified the changes in bone material quality mainly characterized by the preferential orientation of the apatite c-axis associated with estrogen deficiency-induced osteoporosis, and their prevention using ibandronate (IBN), a nitrogen-containing bisphosphonate. IBN effectively prevented bone loss and degradation of whole bone strength in a dose-dependent manner. The estrogen-deficient condition abnormally increased the degree of apatite orientation along the craniocaudal axis in which principal stress is applied; IBN at higher doses played a role in maintaining the normal orientation of apatite but not at lower doses. The bone size-independent Young's modulus along the craniocaudal axis of the anterior cortical shell of the vertebra showed a significant and positive correlation with apatite orientation; therefore, the craniocaudal Young’s modulus abnormally increased under estrogen-deficient conditions, despite a significant decrease in volumetric bone mineral density. However, the abnormal increase in craniocaudal Young's modulus did not compensate for the degradation of whole bone mechanical properties due to the bone loss. In conclusion, it was clarified that changes in the material quality, which are hidden in bone mass evaluation, occur with estrogen deficiency-induced osteoporosis and IBN treatment. Here, IBN was shown to be a beneficial drug that suppresses abnormal changes in bone mechanical integrity caused by estrogen deficiency at both the whole bone and material levels.

Mechanical properties of lithic raw materials from Kazakhstan: comparing chert, shale, and porphyry

The study of lithic raw material quality has become one of the major interpretive tools to investigate the raw material selection behaviour and its influence to the knapping technology. In order to make objective assessments of raw material quality, their mechanical properties (e.g., fracture resistance, hardness, modulus of elasticity) should be measured. However, such comprehensive investigations are lacking for the Palaeolithic of Kazakhstan. In this work, we investigate geological and archaeological lithic raw material samples of chert, porphyry, and shale collected from the Inner Asian Mountain Corridor (henceforth IAMC). Selected samples of aforementioned rocks were tested by means of Vickers and Knoop indentation methods to determine one aspect of their mechanical properties: their indentation fracture resistance (a value closely related to fracture toughness). These tests were complemented by traditional petrographic studies to characterise the mineralogical composition and evaluate the level of impurities that could have potentially affected the mechanical properties. The results show that materials, such as porphyry, previously thought to be of lower quality due to the anisotropic composition and coarse feldspar and quartz phenocrysts embedded in a silica rich matrix, possess fracture toughness values that can be compared to those of chert. Thus, it appears that different raw materials cannot be distinguished from the point of view of indentation fracture resistance, calling for detailed supplementary analyses of different fracture properties. This work also offers first insight into the quality of archaeological porphyry that was utilised as a primary raw material at various Middle and Upper Palaeolithic sites in the IAMC.

Characterization of scar tissue biomechanics during adult murine flexor tendon healing

Tendon injuries are very common and result in significant impairments in mobility and quality of life. During healing, tendons produce a scar at the injury site, characterized by abundant and disorganized extracellular matrix and by permanent deficits in mechanical integrity compared to healthy tendon. Although a significant amount of work has been done to understand the healing process of tendons and to develop potential therapeutics for tendon regeneration, there is still a significant gap in terms of assessing the direct effects of therapeutics on the functional and material quality specifically of the scar tissue, and thus, on the overall tendon healing process. In this study, we focused on characterizing the mechanical properties of only the scar tissue in flexor digitorum longus (FDL) tendons during the proliferative and remodeling healing phases and comparing these properties with the mechanical properties of the composite healing tissue. Our method was sensitive enough to identify significant differences in structural and material properties between the scar and tendon-scar composite tissues. To account for possible inaccuracies due to the small aspect ratio of scar tissue, we also applied inverse finite element analysis (iFEA) to compute mechanical properties based on simulated tests with accurate specimen geometries and boundary conditions. We found that the scar tissue linear tangent moduli calculated from iFEA were not significantly different from those calculated experimentally at all healing timepoints, validating our experimental findings, and suggesting the assumptions in our experimental calculations were accurate. Taken together, this study first demonstrates that due to the presence of uninjured stubs, testing composite healing tendons without isolating the scar tissue overestimates the material properties of the scar itself. Second, our scar isolation method promises to enable more direct assessment of how different treatment regimens (e.g., cellular ablation, biomechanical and/or biochemical stimuli, tissue engineered scaffolds) affect scar tissue function and material quality in multiple different types of tendons.

Development and Effectiveness of Drone as a Learning Media in Islamic Boarding School

Nowadays, drone technology is not only be used in commercial businesses but can also be utilized in a teaching-learning process, including in Islamic boarding school. This article will be discussed the development, performance, feasibility, and effectiveness of drone technology to be utilized as a learning media at Pesantren Hidayatullah Yogyakarta that is one of Islamic boarding school. The developed drone was the multicopter with a multi-rotor type using four rotors. This study was conducted with the development research approach developed by Alessi and Trollip and the descriptive research approach. This drone was applied in teaching-learning process at Pesantren Hidayatullah Yogyakarta. Data were obtained through drone’s testing and observation, interviews, questionnaires for the drone’s affectivity in teaching-learning process. The results of this study can be known that the drone performance is categorized as “Very Good” in terms of functionality and usability aspects. The drone feasibility in the term of material quality and its usefulness is included in the “Very Feasible” category. The drone as learning media has had significantly impact when it’s applied in learning process in extracurricular activities.

Bone Organic-Inorganic Phase Ratio Is a Fundamental Determinant of Bone Material Quality

Background. Bone mineral density is widely used by clinicians for screening osteoporosis and assessing bone strength. However, its effectiveness has been reported unsatisfactory. In this study, it is demonstrated that bone organic-inorganic phase ratio is a fundamental determinant of bone material quality measured by stiffness, strength, and toughness. Methods and Results. Two-hundred standard bone specimens were fabricated from bovine legs, with a specialized manufacturing method that was designed to reduce the effect of bone anisotropy. Bone mechanical properties of the specimens, including Young’s modulus, yield stress, peak stress, and energy-to-failure, were measured by mechanical testing. Organic and inorganic mass contents of the specimens were then determined by bone ashing. Bone density and organic-inorganic phase ratio in the specimens were calculated. Statistical methods were applied to study relationships between the measured mechanical properties and the organic-inorganic phase ratios. Statistical characteristics of organic-inorganic phase ratios in the specimens with top material quality were investigated. Bone organic-inorganic phase ratio had strong Spearman correlation with bone material properties. Bone specimens that had the highest material quality had a very narrow scope of organic-inorganic phase ratio, which could be considered as the “optimal” ratio among the tested specimens. Conclusion. Bone organic-inorganic phase ratio is a fundamental determinant of bone material quality. There may exist an “optimal” ratio for the bone to achieve top material quality. Deviation from the “optimal” ratio is probably the fundamental cause of various bone diseases. This study suggests that bone organic-inorganic phase ratio should be considered in clinical assessment of fracture risk.

Study of the Aging of Cold-Cured SKU-PFL Type Polyurethane Filled with Waste Products

The article describes the results of aging of samples of cold-cured molded polyurethanes of SKU-PFL brand filled with zeolite and silica gel - wastes of petrochemical production. The samples were aged under normal climatic conditions for 5 years. Filling of the samples varied from 10 to 50 %wt. Investigations of physical and mechanical properties of the samples before and after aging were carried out, the basic indicators of material quality were calculated using Microsoft Office Excel package. As a result of researches it was established that after aging the basic physical and mechanical properties of cast polyurethanes of SKU-PFL brand of cold curing filled with zeolite and silica gel change insignificantly, however the best resistance to aging are in samples with 20 %wt. zeolite and 10 %wt. silica gel filling both before and after aging that allowed to recommend them for long-term use of articles.

An Introduction to Montmorillonite Purification

Purification of montmorillonite is a process to remove non clay minerals (gangue) such as calcite, feldspar, quartz, opal (C-T), and mica from montmorillonite ore. This is performed to make montmorillonite suitable for use in sensitive applications such as pharmaceutical, cosmetic, food, and advanced materials for nanotechnology. Gangue minerals in raw montmorillonite ores can cause serious health problems when used in pharmaceutics, cosmetic, and food industries and reduce material quality in advanced materials production. Montmorillonite purification can be divided into two main classes as physical and chemical purification. Physical purification processes are based on particle size difference between the gangue and montmorillonite minerals. Purification processes based on gravity separation are ineffective since the specific weights of gangue and montmorillonite minerals are very close to each other. Physical purification process includes sedimentation, centrifugal separation, aero separation, and sieving techniques. Chemical purification of montmorillonite is based on dissolution and so extraction of carbonates, metal hydroxides, organic materials, and silica, respectively, using different leaching techniques.