scholarly journals An integrative approach to the anatomy of Syllis gracilis Grube, 1840 (Annelida) using micro-computed X-ray tomography

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7251 ◽  
Author(s):  
Julio Parapar ◽  
Carlos Caramelo ◽  
María Candás ◽  
Xela Cunha-Veira ◽  
Juan Moreira

Background The overall anatomy of the genus Syllis (Annelida: Syllidae) has been largely studied; however, an integrative approach considering different anatomical techniques has never been considered. Here, we use micro-computed X-ray tomography (micro-CT) to examine the internal anatomy of Syllis gracilis Grube, 1840, along with other widely available techniques. Methods We studied the anatomy of the marine annelid S. gracilis through an integrative approach, including micro-CT along with stereo and light compound microscopy (STM, LCM), scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM) and histological sectioning (HIS). In this manner, we evaluated the applicability of micro-CT for the examination of annelid anatomy by testing whether the images obtained make it possible to visualize the main body structures, in comparison with other current techniques, of the various elements of its internal anatomy. Results Overall external and internal body elements are clearly shown by the integrative use of all techniques, thus overcoming the limitations of each when studied separately.Any given method shows disparate results, depending on the body part considered. For instance, micro-CT provided good images of the external anatomy, including relevant characters such as the shape, length and number of articles of dorsal parapodial cirri. However, it is especially useful for the examination of internal anatomy, thus allowing for 3D visualization of the natural spatial arrangement of the different organs. The features best visualized are those of higher tissue density (i.e., body musculature, anterior parts of the digestive tract), particularly in 3D images of unstained specimens, whereas less electrodense tissues (i.e., the peritoneal lining of septa and nervous system) are less clearly visualized. The use of iodine stain with micro-CT has shown advantages against non-staining for the adequate observation of delicate elements of low density, such as the segmental organs, the connective between the ganglia, the ventral nerve cord and segmental nerves. Discussion Main external anatomical elements of S. gracilis are well shown with micro-CT, but images show lesser optical resolution and contrast when compared to micrographs provided by SEM and CLSM, especially for fine structural features of chaetae. Comparison of micro-CT and HIS images revealed the utility and reliability of the former to show the presence, shape and spatial disposition of most internal body organs; the resolution of micro-CT images at a cellular level is, however, much lower than that of HIS, which makes both techniques complementary.

2010 ◽  
Vol 16 (5) ◽  
pp. 550-560 ◽  
Author(s):  
Andrzej Woznica ◽  
Jagna Karcz ◽  
Agnieszka Nowak ◽  
Aleksander Gmur ◽  
Tytus Bernas

AbstractWe describe the architecture of nitrifying bacteria biofilms immobilized on a three-dimensional (3D) polyurethane foam that permits efficient water flow through a bioreactor. The 3D spatial organization of immobilized bacterial colonies is characterized on three resolution levels with X-ray tomography, light confocal microscopy, and scanning electron microscopy (SEM). Using these techniques we demonstrate biofilm distribution in the foam and the existence of several modes of binding of bacteria to the foam. Computed X-ray tomography permits observation of the distribution of the biofilm in the whole open cellular polyurethane material volume and estimation of biofilm volume. SEM and confocal laser scanning microscopy techniques permit 3D visualization of biofilm structure. Three distinct immobilization patterns could be observed in the open cellular polyurethane material: (1) large irregular aggregates of bacterial biofilm that exist as irregular biofilm fragments, rope-like structures, or biofilm layers on the foam surface; (2) spherical (pom-pom) aggregates of bacteria localized on the external surface of biofilm; and (3) biofilm threads adherent to the surface of polyurethane foam. Finally, we demonstrate that immobilized bacteria exhibit metabolic activity and growth.


2008 ◽  
Vol 396-398 ◽  
pp. 569-572
Author(s):  
Fumio Watari ◽  
Shigeaki Abe ◽  
I.D. Rosca ◽  
Atsuro Yokoyama ◽  
Motohiro Uo ◽  
...  

Nanoparticles may invade directly into the internal body through the respiratory or digestive system and diffuse inside body. The behavior of nanoparticles in the internal body is also essential to comprehend for the realization of DDS. Thus it is necessary to reveal the internal dynamics for the proper treatments and biomedical applications of nanoparticles. In the present study the plural methods with different principles such as X-ray scanning analytical microscope (XSAM), MRI and Fluorescent microscopy were applied to enable the observation of the internal diffusion of micro/nanoparticles in the (1) whole body level, (2) inner organ level and (3) tissue and intracellular level. Chemical analysis was also done by ICP-AES for organs and compared with the results of XSAM mapping.


Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 464
Author(s):  
Simona Liliana Iconaru ◽  
Mihai Valentin Predoi ◽  
Patrick Chapon ◽  
Sofia Gaiaschi ◽  
Krzysztof Rokosz ◽  
...  

In this study, the cerium-doped hydroxyapatite (Ca10−xCex(PO4)6(OH)2 with xCe = 0.1, 10Ce-HAp) coatings obtained by the spin coating method were presented for the first time. The stability of the 10Ce-HAp suspension particles used in the preparation of coatings was evaluated by ultrasonic studies, transmission electron microscopy (TEM), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The surface morphology of the 10Ce-HAp coating was studied by SEM and atomic force microscopy (AFM) techniques. The obtained 10Ce-HAp coatings were uniform and without cracks or unevenness. Glow discharge optical emission spectroscopy (GDOES) and X-ray photoelectron spectroscopy (XPS) were used for the investigation of fine chemical depth profiling. The antifungal properties of the HAp and 10Ce-HAp suspensions and coatings were assessed using Candida albicans ATCC 10231 (C. albicans) fungal strain. The quantitative antifungal assays demonstrated that both 10Ce-HAp suspensions and coatings exhibited strong antifungal properties and that they successfully inhibited the development and adherence of C. albicans fungal cells for all the tested time intervals. The scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) visualization of the C. albicans fungal cells adherence to the 10Ce-HAp surface also demonstrated their strong inhibitory effects. In addition, the qualitative assays also suggested that the 10Ce-HAp coatings successfully stopped the biofilm formation.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4072
Author(s):  
Benedikt Kirchebner ◽  
Maximilian Ploetz ◽  
Christoph Rehekampff ◽  
Philipp Lechner ◽  
Wolfram Volk

Like most additive manufacturing processes for metals, material jetting processes require support structures in order to attain full 3D capability. The support structures have to be removed in subsequent operations, which increases costs and slows down the manufacturing process. One approach to this issue is the use of water-soluble support structures made from salts that allow a fast and economic support removal. In this paper, we analyze the influence of salt support structures on material jetted aluminum parts. The salt is applied in its molten state, and because molten salts are typically corrosive substances, it is important to investigate the interaction between support and build material. Other characteristic properties of salts are high melting temperatures and low thermal conductivity, which could potentially lead to remelting of already printed structures and might influence the microstructure of aluminum that is printed on top of the salt due to low cooling rates. Three different sample geometries have been examined using optical microscopy, confocal laser scanning microscopy, energy-dispersive X-ray spectroscopy and micro-hardness testing. The results indicate that there is no distinct influence on the process with respect to remelting, micro-hardness and chemical reactions. However, a larger dendrite arm spacing is observed in aluminum that is printed on salt.


CORROSION ◽  
10.5006/3234 ◽  
2019 ◽  
Vol 75 (12) ◽  
pp. 1474-1486
Author(s):  
Jéssica Cristina Costa de Castro Santana ◽  
Rejane Maria Pereira da Silva ◽  
Renato Altobelli Antunes ◽  
Sydney Ferreira Santos

The aim of the present work was to study the surface chemistry, microstructure, and local corrosion processes at the decarburized layer of the SAE 9254 automotive spring steel. The samples were austenitized at 850°C and 900°C, and oil quenched. The microstructure was investigated using confocal laser scanning microscopy and scanning electron microscopy. The surface chemistry was analyzed by x-ray photoelectron spectroscopy. Electrochemical impedance spectroscopy and potentiodynamic polarization were used to assess the global corrosion behavior of the decarburized samples. Scanning electrochemical microscopy was used to evaluate the influence of decarburization on the local corrosion activity. Microstructural characterization and x-ray photoelectron spectroscopy analysis indicate a dependence of the local electrochemical processes with the steel microconstituents and Si oxides in the decarburized layer.


2012 ◽  
Vol 487 ◽  
pp. 730-734 ◽  
Author(s):  
Chang Jiang Pan ◽  
Yu Dong Nie ◽  
Yun Xiao Dong

In this paper, two kinds of stamps (squares (a×a)) separated by spacing b, the values of a and b were varied from 2.5 µm to 50 µm), i.e. positive and negative stamps, were prepared. The stamps inked with the rhodamine-labeled bovine serum albumin (BSA) were then microcontacted with the aldehyde-functionalized titanium surfaces. Water contact angle and X-ray photoelectron spectrum (XPS) indicated that BSA can be covalently immobilized on aldehyde modified titanium surface by microcontact printing. The experimental results of CLSM showed that the patterns with resolution from 2.5 µm to 50 µm were obtained successfully. Both positive stamp and negative stamp were deformed when the value of a was less than or equal to 5 µm, which resulted in replication errors. Furthermore, the larger spacing (50 µm) resulted in stamp collapse when the value a of the positive stamp was less than or equal to 10 µm, leading to whole fluorescence on substrates.


Author(s):  
Sthefane D'ávila ◽  
Pedro Paulo de Abreu Manso ◽  
Elizabeth Cristina de Almeida Bessa ◽  
Maria de Lurdes de Azevedo Rodrigues

The aim of this study was to obtain data on the morphology and morphometry of pre-ovigerous and post-ovigerous adults of the species Tanaisia (Paratanaisia) bragai, using confocal laser scanning microscopy to obtain tomographic images of the suckers and tegument. For morphometric analysis, 45 specimens (30 pre-ovigerous adults and 15 post-ovigerous adults) were measured with the aid of an ocular micrometer coupled to the objective of a photonic microscope. Pre-ovigerous and post-ovigerous adult individuals, stained with Mair carmalumen and mounted in permanent preparations, were analyzed by means of confocal laser scanning microscopy. Positive correlation was detected between the body length and ovary length of post-ovigerous adults (rs: 0.774; p<0.01), as well as between the body length and testes (rs: 0.604 and 0.659; p< 0.05), the body length and the length of uterus (rs: 0.839; p< 0,01) and between the ovary width and egg length (rs: 0.777; p<0.01). Morphological study of the pre-ovigerous adults demonstrated that the ovary and testes develop simultaneously before the development of the uterus and vitelline glands. The acetabulum was detected in pre-ovigerous adults stained with hematoxilin and observed using light microscopy. In these specimens, the acetabulum measured 36.7 ± 6.9 µm (25-50 µm) in width and 39.91 ± 6.8 µm (25-55 µm) in length. The acetabulum was not detected in post-ovigerous adults observed with light microscopy. However, this structure was detected using confocal miscrocopy. In the post-ovigerous specimens, the acetabulum presented a reduced size compared to the pre-ovigerous adults. This may imply that this structure has more functional significance in the larval and pre-ovigerous stages.


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