Cuticular microstructures and their relationship to structural color and transpiration in the terrestrial isopod Porcellionides pruinosus

1985 ◽  
Vol 63 (3) ◽  
pp. 649-656 ◽  
Author(s):  
Neil F. Hadley ◽  
Gregory M. Hendricks

The microstructure of the dorsal surface of the terrestrial isopod Porcellionides pruinosus was examined by scanning electron microscopy. Surface structures detected include sensory tricorns, spherical particles (balls) of various diameter, plates formed from the fusion of adjacent balls, and extremely small granules. A rod-shaped bacterium was also present on the surface of most individuals. The cuticular balls scatter and reflect incident light, producing a grayish white color or frosted appearance in most intermolt isopods. Prior to a molt, individuals are characteristically brown or unfrosted owing to the loss of the balls from the cuticle surface. New balls appear within a few hours following ecdysis and the isopod soon reacquires the frosted appearance. The balls are insoluble in lipid solvents and are also resistant to acetic acid and KOH. Higher water loss rates in unfrosted versus frosted individuals suggest that one function of the balls is to reduce cuticular transpiration in this species.

Author(s):  
Jane A. Westfall ◽  
S. Yamataka ◽  
Paul D. Enos

Scanning electron microscopy (SEM) provides three dimensional details of external surface structures and supplements ultrastructural information provided by transmission electron microscopy (TEM). Animals composed of watery jellylike tissues such as hydras and other coelenterates have not been considered suitable for SEM studies because of the difficulty in preserving such organisms in a normal state. This study demonstrates 1) the successful use of SEM on such tissue, and 2) the unique arrangement of batteries of nematocysts within large epitheliomuscular cells on tentacles of Hydra littoralis.Whole specimens of Hydra were prepared for SEM (Figs. 1 and 2) by the fix, freeze-dry, coat technique of Small and Màrszalek. The specimens were fixed in osmium tetroxide and mercuric chloride, freeze-dried in vacuo on a prechilled 1 Kg brass block, and coated with gold-palladium. Tissues for TEM (Figs. 3 and 4) were fixed in glutaraldehyde followed by osmium tetroxide. Scanning micrographs were taken on a Cambridge Stereoscan Mark II A microscope at 10 KV and transmission micrographs were taken on an RCA EMU 3G microscope (Fig. 3) or on a Hitachi HU 11B microscope (Fig. 4).


Author(s):  
P. Evers ◽  
C. Schutte ◽  
C. D. Dettman

S.rodhaini (Brumpt 1931) is a parasite of East African rodents which may possibly hybridize with the human schistosome S. mansoni. The adult male at maturity measures approximately 3mm long and possesses both oral and ventral suckers and a marked gynaecophoric canal. The oral sucker is surrounded by a ring of sensory receptors with a large number of inwardly-pointing spines set into deep sockets occupying the bulk of the ventral surface of the sucker. Numbers of scattered sensory receptors are found on both dorsal and ventral surfaces of the head (Fig. 1) together with two conspicuous rows of receptors situated symmetrically on each side of the midline. One row extends along the dorsal surface of the head midway between the dorsal midline and the lateral margin.


Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 968
Author(s):  
Paul Monchot ◽  
Loïc Coquelin ◽  
Khaled Guerroudj ◽  
Nicolas Feltin ◽  
Alexandra Delvallée ◽  
...  

The size characterization of particles present in the form of agglomerates in images measured by scanning electron microscopy (SEM) requires a powerful image segmentation tool in order to properly define the boundaries of each particle. In this work, we propose to use an algorithm from the deep statistical learning community, the Mask-RCNN, coupled with transfer learning to overcome the problem of generalization of the commonly used image processing methods such as watershed or active contour. Indeed, the adjustment of the parameters of these algorithms is almost systematically necessary and slows down the automation of the processing chain. The Mask-RCNN is adapted here to the case study and we present results obtained on titanium dioxide samples (non-spherical particles) with a level of performance evaluated by different metrics such as the DICE coefficient, which reaches an average value of 0.95 on the test images.


Author(s):  
Д.А. Кочуев ◽  
К.С. Хорьков ◽  
А.С. Черников ◽  
Р.В. Чкалов ◽  
В.Г. Прокошев

The paper presents the results of processing titanium surface in n-hexane at various pressures by femtosecond laser radiation. The effect of laser-induced plasma on the nature of the formation of periodic surface structures in the pressure range from 6 mbar to 22 bar is considered. The study of the surface of the processed samples was carried out using scanning electron microscopy. The dependence of the period of obtained laser-induced periodic surface structures on the pressure in working vessel and the treatment regime is shown.


Author(s):  
MONTUKUMAR PATEL ◽  
NIRAV V. PATEL ◽  
TEJAS B. PATEL

Objective: The primary objective of the current research was to prepare rilpivirine loaded Nanoparticles containing Chitosan using the ionic gelation method for HIV infections. Methods: The nanoparticles of rilpivirine were prepared using the ionic gelation technique. Further, nanoparticles were characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and in vitro drug release. Results: The optimized nanoparticles were found with a particle size of 130.30±5.29 nm (mean±SD) and entrapment efficiency (% EE) of 77.10±0.50%. Scanning electron microscopy technique exposed spherical particles with uniform size. It was observed that the nanoparticles created showed the absence of the crystalline nature of the drug and its switch to the amorphous state. Results showed that more than 45% of the pure drug is released in 50 min and after 90 min almost about 95% of the drug is released. Conclusion: The research study concluded that the in vitro release profile of nanoparticles was found to be sustained up to 24 hr. Sustained release of the rilpivirine could improve patient obedience to drug regimens, growing action effectiveness. 


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