Scale-based landmark for internal organs assessments of common carp (Cyprinus carpio) during digital radiography and ultrasonography imaging.

Medical imaging techniques such as digital radiography and ultrasonography are non-invasive and provide precise results for examining internal organs and structures within fish. Their effectiveness can be further enhanced by using body parts like scales as markers for the organs beneath them. This study utilized the number of scales as landmarks in digital radiography and ultrasonography to non-invasively evaluate the muscles, bones, and images of internal and reproductive organs of common carp (Cyprinus carpio). Digital radiography was performed in the dorsoventral and lateral views of the fish, whereas ultrasonography was conducted in longitudinal and transverse views on sequence scale numbers with brightness and colour Doppler-modes. Digital radiography of the common carp revealed the whole-body morphology, including the bony parts from the head, pectoral fins, dorsal fins, pelvic fins, anal fins, and vertebrae to the tail that appeared radiopaque. Internal organs were also observed, with the swim bladder and heart appeared radiolucent, while the intestines, liver, testes, and ovaries appeared radiopaque. Ultrasonography in brightness mode displayed the digestive organs, reproductive organs, and muscle thickness. Additionally, colour Doppler mode demonstrated blood flow within the heart's ventricle.

The visualisation of fingermarks on Pangolin scales using gelatine lifters.

Recent media reports document the plight of the Pangolin and its current position as "the most trafficked mammal in the world". They are described by some as scaly anteaters as all species are covered in hard keratinous tissue in the form of overlapping scales acting as a "flexible dermal armour". It is estimated that between 2011 and 2013, 117,000-234,000 pangolins were slaughtered, but the seizures may only represent as little as 10% of the true volume of pangolins being illegally traded. In this paper, methods to visualise fingermarks on Pangolin scales using gelatine lifters is presented. The gelatine lifters provide an easy to use, inexpensive but effective method to help wildlife crime rangers across Africa and Asia to disrupt the trafficking. The gelatine lifting process visualised marks producing clear ridge detail on 52% of the Pangolin scales examined, with a further 30% showing the impression of a finger with limited ridge detail. The paper builds on an initial sociotechnical approach to establishing requirement, then it focuses on the methods and outcomes relating to lifting fingermarks off Pangolin scales using gelatine lifters, providing an evaluation of its use in practice.

Role of Surface Chemistry in the Superhydrophobicity of the Springtail Orchesella cincta (Insecta:Collembola).

Collembola are ancient arthropods living in soil with extensive exposure to dirt, bacteria, and fungi. To protect from the harsh environmental conditions and to retain a layer of air for breathing when submerged in water, they have evolved a superhydrophobic, liquid-repelling cuticle surface. The nonfouling and self-cleaning properties of springtail cuticle make it an interesting target of biomimetic materials design. Recent research has mainly focused on the intricate microstructures at the cuticle surface. Here we study the role of the cuticle chemistry for the Collembola species Orchesella cincta (Collembola, Entomobryidae). O. cincta uses a relatively simple cuticle structure with primary granules arranged to function as plastrons. In contrast to the Collembolan cuticle featuring structures on multiple length scales that is functional irrespective of surface chemistry, we found that the O. cincta cuticle loses its hydrophobic properties after being rinsed with dichloromethane. Sum frequency generation spectroscopy and time-of-flight secondary ion mass spectrometry in combination with high-resolution mass spectrometry show that a nanometer thin triacylglycerol-containing wax layer at the cuticle surface is essential for maintaining the antiwetting properties. Removal of the wax layer exposes chitin, terpenes, and lipid layers in the cuticle. With respect to biomimetic applications, the results show that, combined with a carefully chosen surface chemistry, superhydrophobicity may be achieved using a relatively unsophisticated surface structure rather than a complex, re-entrant surface structure alone.

Ab initio nonrigid X-ray nanotomography.

Reaching the full potential of X-ray nanotomography, in particular for biological samples, is limited by many factors, of which one of the most serious is radiation damage. Although sample deformation caused by radiation damage can be partly mitigated by cryogenic protection, it is still present in these conditions and, as we exemplify here using a specimen extracted from scales of the Cyphochilus beetle, it will pose a limit to the achievable imaging resolution. We demonstrate a generalized tomographic model, which optimally follows the sample morphological changes and attempts to recover the original sample structure close to the ideal, damage-free reconstruction. Whereas our demonstration was performed using ptychographic X-ray tomography, the method can be adopted for any tomographic imaging modality. Our application demonstrates improved reconstruction quality of radiation-sensitive samples, which will be of increasing relevance with the higher brightness of 4th generation synchrotron sources.

Mechanical behavior of ctenoid scales: Joint-like structures control the deformability of the scales in the flatfish Solea solea (Pleuronectiformes).

Ctenoid scales protect the fish body against predators and other environmental impacts. At the same time, they allow for sufficient degree of flexibility to perform species-specific locomotion. The scales of the flatfish Solea solea were chosen to study the specific mechanical behavior and material properties of the ctenoid scales. Using scanning electron microscopy and micro-computed tomography, three-dimensional asymmetric structures of the stacked mineralized ctenial spines in the posterior field, which is a part of the scales exposed to the environment, were examined in detail. Nanoindentations on the surface of the ctenial spines indicated that the elastic modulus and hardness of these mineralized structures are about 14 GPa and 0.4 GPa, respectively. The spines appeared to be connected to each other by means of joint-like structures containing soft tissues. Bending tests showed that the ctenoid scales have two functional zones: a stiff supporting main body and an anisotropically deformable posterior field. While the stiff plate-like main body provides support for the whole scale, the deformable joint-like structures in the ctenial spines increase the deformability of the posterior field in downward bending. During upward bending, however, the spines prevent complete folding of the posterior field by an interlocking effect. STATEMENT OF SIGNIFICANCE: In contrast to the continuously mineralized cycloid scales, ctenoid scales combine two conflicting properties: They are hard to protect the body of fish against predators and other environmental impacts, yet flexible enough to allow for sufficient degree of body bendability for locomotion. To understand the structural background underlying this specific biomechanical feature, here we investigated the scales of the flatfish Solea solea. For the first time, we demonstrated the presence of joint-like structures within the scales, which increase scale deformability during downward bending, but prevent scale deformation during upward bending by interlocking. Our results shed lights on the material-structure-function relationships in ctenoid scales, as well as on their functional adaptations to the specific environment.