Creating artificial Rhino Horns from Horse Hair.

Demand for rhino horn is driving poaching with devastating effect for the few individuals left of the few species surviving from this once numerous, widespread and cosmopolitan clade of pachyderms. We bundled together tail hairs of the rhino's ubiquitous near relative, the horse, to be glued together with a bespoke matrix of regenerated silk mimicking the collagenous component of the real horn. This approach allowed us to fabricate composite structures that were confusingly similar to real rhino horn in look, feel and properties. Spectral and thermal FT-IR, DSC and TGA analysis demonstrated the similar chemical composition and thermo-mechanical properties between the natural and the faux horns.

Moisture, anisotropy, stress state, and strain rate effects on bighorn sheep horn keratin mechanical properties.

This paper investigates the effects of moisture, anisotropy, stress state, and strain rate on the mechanical properties of the bighorn sheep (Ovis Canadensis) horn keratin. The horns consist of fibrous keratin tubules extending along the length of the horn and are contained within an amorphous keratin matrix. Samples were tested in the rehydrated (35wt% water) and ambient dry (10wt% water) conditions along the longitudinal and radial directions under tension and compression. Increased moisture content was found to increase ductility and decrease strength, as well as alter the stress state dependent nature of the material. The horn keratin demonstrates a significant strain rate dependence in both tension and compression, and also showed increased energy absorption in the hydrated condition at high strain rates when compared to quasi-static data, with increases of 114% in tension and 192% in compression. Compressive failure occurred by lamellar buckling in the longitudinal orientation followed by shear delamination. Tensile failure in the longitudinal orientation occurred by lamellar delamination combined with tubule pullout and fracture. The structure-property relationships quantified here for bighorn sheep horn keratin can be used to help validate finite element simulations of ram's impacting each other as well as being useful for other analysis regarding horn keratin on other animals. STATEMENT OF SIGNIFICANCE: The horn of the bighorn sheep is an anisotropic composite composed of keratin that is highly sensitive to moisture content. Keratin is also found in many other animals in the form of hooves, claws, beaks, and feathers. Only one previous study contains high rate experimental data, which was performed in the dry condition and only in compression. Considering the bighorn sheep horns' protective role in high speed impacts along with the moisture and strain rate sensitivity, more high strain rate data is needed to fully characterize and model the material. This study provides high strain rate results demonstrating the effects of moisture, anisotropy, and stress state. As a result, the comprehensive data allows modeling efforts to be greatly improved.

Microstructure and mechanical properties of sheep horn.

The sheep horn presents outstanding mechanical properties of impact resistance and energy absorption, which suits the need of the vehicle bumper design, but the mechanism behind this phenomenon is less investigated. The microstructure and mechanical properties of the sheep horn of Small Tailed Han Sheep (Ovis aries) living in northeast China were investigated in this article. The effect of sampling position and orientation of the sheep horn sheath on mechanical properties were researched by tensile and compression tests. Meanwhile, the surface morphology and microstructure of the sheep horn were observed using scanning electron microscopy (SEM). The formation mechanism of the mechanical properties of the sheep horn was investigated by biological coupling analysis. The analytical results indicated that the outstanding mechanical properties of the sheep horn are determined by configuration, structure, surface morphology and material coupling elements. These biological coupling elements make the sheep horn possess super characteristics of crashworthiness and energy absorption through the internal coupling mechanism. We suppose that these findings would make a difference in vehicle bumper design. Microsc. Res. Tech. 79:664-674, 2016. © 2016 Wiley Periodicals, Inc.

[Mechanical properties and biological evaluation of buffalo horn material].

Mechanical properties and biological evaluation of buffalo horn material were examined in this study. The effects of sampling position of buffalo horn on mechanical properties were investigated with uniaxial tension and micron indentation tests. Meanwhile, the variation of element contents in different parts of buffalo horn was determined with elemental analysis, and the microstructure of the horn was measured with scanning electron microscopy. In addition, biological evaluation of buffalo horn was studied with hemolytic test, erythrocyte morphology, platelet and erythrocyte count, and implantation into mouse. Results showed that the buffalo horn had good mechanical properties and mechanical characteristic values of it gradually increased along with the growth direction of the horn, which may be closely related to its microstructure and element content of C, N, and S in different parts of the buffalo horn. On the other hand, because the buffalo horn does not have toxicity, it therefore does not cause hemolysis of erythrocyte and has a good affinity with it. Buffalo horn has good histocompatibility but meanwhile it may induce the platelet adhesion and aggregation. Even so, it does not continue to rise to induce a large number of platelet to aggregate with resulting blood clotting. Therefore, the buffalo horn material has been proved to possess good blood compatibility according to the preliminary evaluation.

Experimental study on the mechanical properties of the horn sheaths from cattle.

Bovine horn is composed of a sheath of keratin overlying a bony core. Previous studies of the bovine horn sheath have focused mainly on its morphology and compositions. In the present paper, we performed a series of uniaxial tension, three-point bending, and fracture tests to investigate the structural and mechanical properties of the horn sheaths from subadult cattle, Bos taurus. The effects of hydration on the mechanical properties were examined and their variations along the longitudinal direction of the horn sheath were addressed. Scanning electron microscopy of the fracture surfaces showed that the horn sheath has a layered structure and, more interestingly, the laminae have a rippled appearance. The Young's modulus and tensile strength increase from 850 MPa and 40 MPa at 19% water content to 2.3 GPa and 154 MPa at 0% water content, respectively. The Poisson's ratio of the horn sheath was about 0.38. The critical stress intensity factor was about 4.76 MPa m1/2 at an intermediate hydration (8% water content), greater than that at 0% water content (3.86 MPa m1/2) and 19% water content (2.56 MPa m1/2). The bending properties of the samples varied along the length of the horn. The mean flexural moduli of the specimens in the distal, middle and proximal parts were about 6.26 GPa, 5.93 GPa and 4.98 GPa, respectively; whereas the mean yield strength in the distal segment was about 152.4 MPa, distinctly higher than that in the middle (135.7 MPa) and proximal parts (116.4 MPa). This study deepens our understanding of the relationships among optimal structure, property and function of cattle horn sheaths.

[Microscopic quantitative study on Saiga tatarica in "lingyang qing fei pill"].

OBJECTIVE: To determine Saiga tatarica content in "Lingyang Qing Fei Pill". METHODS: Volumetric analysis combined with quantitative microscopy was used to determine Saiga tatarica content by sample itself as standard substance. RESULT AND CONCLUSION: The method of determining the content of Saiga tatarica is simple and creditable.

Method for preparing thin sections of untreated equine hoof horn for electron microscopic examination.

The preparation of hard tissues such as the equine hoof horn for electron microscopic examination is very difficult. In particular the penetration of fixatives and chemicals used during fixation and embedding is a problem. The objective of this study was to find and implement an alternative method enabling the preparation of high-quality thin sections of hoof horn and other hard tissue, which maintains the hard tissue ultrastructure and can be used for immuno-labeling. Compared to commonly used fixation and embedding techniques, the preparation of thin sections from untreated material method saves time and material and provides equivalent ultrastructural information. Furthermore, thin sections from untreated material are significantly larger and more homogeneous, more resistant to the electron ray, as well as more suitable for sectioning. The electron microscopical pictures obtained allow a comparison to previous test results achieved with fixed and embedded material. Using the preparation of thin sections from untreated material method, fixation and embedding artifacts are avoided, providing a clearer interpretation of the electron microscopical findings. Considerable advantages are achieved by using immunohistochemical techniques with untreated horn specimens because fixation invariably decreases antigenicity.

Morphological character of crystalline components present in saiga horn.

The purpose of this study was to investigate the ultrastructure of saiga-antelope (Saiga tatarica) horn for proposing the mechanism of the initial mineralization. Horn is derived from horny tooth of Cyclostomata. The minerals in saiga horn were identified crystallographically using electron microscopy and X-ray diffraction techniques. Soft X-ray photographs revealed the degree of the mineralization pattern. However, the number of rings did not indicate the age of saiga. Mineral deposites were observed among well banded keratin fibers and composed of powder like crystals. This deposited crystals were found by the X-ray diffraction method to be octacalcium phospate (OCP) by comparing these periodic lattice fringes to JCPDS card data. The chemical formula of OCP is Ca8H2(PO4)6.5H2O. Evidences for the presence of OCP in mature hard tissues have never been obtained. This phenomenon described here may be characteristic of saiga horn because we have found no reports on this type of OCP mineralization in any other animal species. It is possible that OCP is the precursor in the initial mineralization step, indicating in a nucleation of mineral on the keratin fibers.

[Pharmacognostical identification of antelope horn(Cornu Saigae Tataricae) and its adulterants].

OBJECTIVE: To provide appropriate information and scientific basis for identifying antelope horn (Saiga tatarica) contained in traditional Chinese patent medicines, and formulate relevant quality criteria through experiments. METHOD: Conducting comparative identification of macroscopic and microscopic characteristics of antelope horn(Saige tatarica) and its adulterants (Procapra gutturosa, Pantholops hodgsoni, Ovis ammon and Capra hircus) and giving a comparative table and an indented key to the main characteristics. RESULT AND CONCLUSION: There are remarkable differences between the authentic product and adulterants in both macroscopic and microscopic characteristics.

Consistency in calibrated backscattered electron images of calcified tissues and minerals analyzed in multiple imaging sessions.

Pure metal standards have been used to calibrate the operating envionment in quatitative backscattered electron (BSE) imaging of mineralized tissue, allowing comparisons to be made between various mineralization states of bone at the microscopic level. It has not previuously been documented that calibration procedures produce consistent, reliable results over multiple imaging sessions. In this study, BSE images were obtained from bones, pure metals, and a naturally occurring mineral in multiple imaging sessions over a six day period. The graylevel histogram profile (GHP) from each specimen was analyzed for changes in the shape and relative placement on the graylevel spectrum. Computer controlled calibration and a restrospective calibration method using pure aluminum and pure magnesium-aluminum-zinc demonstrated consistency between imaging sessions. Calibrated weighted mean graylevels (WMGLs) for biological meterials had an average standard deviation of 5.9 graylevels (2.4% variation) during the course of the study. WMGLs for inorganic materials had an average standard deviation of 0.9 graylevels (0.4% variation). A trend towards increased image brightness, due to specimen and/or embedding media degradation, was observed in the biological tissues. No increase in rightness was observed for the inorgtanic specimens. Kurtosis and skewness tests revealed a slight deviation from normality in all specimens, which remained consistent between multiple imaging sessions. These results demonstrate the BSE image analysis of bones and mineral can be calibrated with negligible precision error allowing comparisons between data within and between multiple imaging sessions.