Glycerol decreases the integrity of the perinuclear theca in boar sperm

Zygote ◽  
2012 ◽  
Vol 21 (2) ◽  
pp. 172-177 ◽  
Author(s):  
Marco Antonio Arenas Núñez ◽  
María de Lourdes Juárez-Mosqueda ◽  
Oscar Gutiérrez-Pérez ◽  
Santiago René Anzaldúa Arce ◽  
Alejandro Córdova Izquierdo ◽  
...  

SummaryWe evaluated the effect of glycerol on the perinuclear theca (PT) of boar sperm. Samples from six ejaculates obtained from three different boars were incubated in the detergent Brij 36-T. Spermatozoa were treated with a glycerol concentration of either 2 or 4%, and incubated for 10 or 30 min; two other samples were treated with protease inhibitors (PI; leupeptin or an inhibitor commercial cocktail), mixed with 4% glycerol, and incubated for 30 min. A third glycerol-free group was used as the control. The samples were processed for electron microscopy evaluation. The PT remained intact in 78% of the control samples while, after addition of glycerol for 30 min, the proportion of spermatozoa with disrupted or absent PT increased (P < 0.05). PT was preserved in PI samples, but PT changes increased (P < 0.05). Differences due to treatment with glycerol (2 or 4%) at 10 or 30 min were not observed. These results show, to our knowledge for the first time, the adverse effect of glycerol on the integrity of the PT.

Author(s):  
D. L. Misell

In the electron microscopy of biological sections the adverse effect of chromatic aberration on image resolution is well known. In this paper calculations are presented for the inelastic and elastic image intensities using a wave-optical formulation. Quantitative estimates of the deterioration in image resolution as a result of chromatic aberration are presented as an alternative to geometric calculations. The predominance of inelastic scattering in the unstained biological and polymeric materials is shown by the inelastic to elastic ratio, I/E, within an objective aperture of 0.005 rad for amorphous carbon of a thickness, t=50nm, typical of biological sections; E=200keV, I/E=16.


Author(s):  
Mamaeva S.N. ◽  
Vinokurov R.R. ◽  
Munkhalova Ya.A. ◽  
Dyakonova D.P. ◽  
Platonova V.A. ◽  
...  

Currently, due to the intensive development of high-tech science-intensive medical and research devices, more and more attention is paid to the development of diagnostics of rare and difficult to diagnose diseases. It is known that among numerous nephropathies, hematuria may be the only symptom of kidney and urinary tract diseases, which complicates their diagnosis and treatment. In order to develop new approaches for the diagnosis of nephropathies, the authors have been studying the morphology of red blood cells in the blood and urine of children and adults using a scanning electron microscope for several years. The paper presents the results of studies of children with various kidney diseases, including IgA-nephropathy, and chronic glomerulonephritis. Scanning electron microscopy was used for the first time to detect nanoparticles on the surface of red blood cells, the size of which is comparable to the size of viruses, which became the basis for one of the authors ' assumptions, namely, the possible transport of certain types of viruses by red blood cells. Thus, some kidney diseases could be considered virus-associated. This paper presents for the first time the results of determining the glomerular filtration rate of both kidneys separately in the study of separate kidney function and of the study of urine smears obtained during catheterization of the ureters in patients with hydronephrosis of one of the kidneys by scanning electron microscopy. As in previous studies, nanoparticles were found on the surface of red blood cells, which leads to the conclusion about the possible viral nature of the disease of the considered patient. In addition, smear images obtained using a microscope showed a significant difference in the elements of the right and left kidneys urine, which did not contradict the data on the study of glomerular filtration rate. According to the authors, the capabilities of the scanning electron microscope can be applied in fundamental research of kidney diseases at the cellular and molecular levels, forming new ideas about their origin, as well as on the basis of which new methods of non-invasive diagnostics can be built.


Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 611
Author(s):  
Celia Marcos ◽  
María de Uribe-Zorita ◽  
Pedro Álvarez-Lloret ◽  
Alaa Adawy ◽  
Patricia Fernández ◽  
...  

Chert samples from different coastal and inland outcrops in the Eastern Asturias (Spain) were mineralogically investigated for the first time for archaeological purposes. X-ray diffraction, X-ray fluorescence, transmission electron microscopy, infrared and Raman spectroscopy and total organic carbon techniques were used. The low content of moganite, since its detection by X-ray diffraction is practically imperceptible, and the crystallite size (over 1000 Å) of the quartz in these cherts would be indicative of its maturity and could potentially be used for dating chert-tools recovered from archaeological sites. Also, this information can constitute essential data to differentiate the cherts and compare them with those used in archaeological tools. However, neither composition nor crystallite size would allow distinguishing between coastal and inland chert outcrops belonging to the same geological formations.


2020 ◽  
Vol 307 (1) ◽  
Author(s):  
Mytnik Joanna ◽  
Davies L. Kevin ◽  
Narajczyk Magdalena ◽  
Łuszczek Dorota ◽  
Kubiak Joanna ◽  
...  

AbstractPolystachya is a large, pantropical orchid genus of 200 species, most of which occur as epiphytes in sub-saharan Africa. The three-lobed labellum of most Polystachya species possesses a fleshy callus and various types of trichomes and papillae. In this paper, we present the results of micromorphological studies on the labellum of 20 species, representing eight of the 13 sections in the genus, using scanning electron microscopy (SEM). Our results show the scale of infrageneric diversity of trichomes and papillae relative to the sampled sections. They also demonstrate the taxonomic value of labellar micromorphology at the sectional level. The study revealed seven types of papillae and five types of trichomes (uni- and multi-cellular) in Polystachya, some of which, are described here for the first time. Clavate trichomes are the most common and are present in 60% of the species studied. Moniliform trichomes mainly occur in sect. Polystachya and are strongly characteristic of the section. Pseudopollen is formed by fragmentation of moniliform trichomes or the detachment of other trichomes as bicellular units. We provide, for the first time, evidence for the detachment of the terminal cells of capitate trichomes.


2019 ◽  
Vol 1 (4) ◽  
pp. 1581-1588 ◽  
Author(s):  
S. I. Sadovnikov ◽  
E. Yu. Gerasimov

For the first time, the α-Ag2S (acanthite)–β-Ag2S (argentite) phase transition in a single silver sulfide nanoparticles has been observed in situ using a high-resolution transmission electron microscopy method in real time.


2017 ◽  
Vol 23 (3) ◽  
pp. 679-686 ◽  
Author(s):  
Milan Gavrilović ◽  
Suzana Erić ◽  
Petar D. Marin ◽  
Núria Garcia-Jacas ◽  
Alfonso Susanna ◽  
...  

AbstractIn this work, weddellite and sylvite crystals are identified for the first time on the involucral bracts and petals of Xeranthemum annuum and Xeranthemum cylindraceum using scanning electron microscopy coupled with energy dispersive spectrometric (SEM-EDS) analysis. Well-developed crystals of weddellite (CaC2O4·2H2O) occur in the form of a tetragonal bipyramid (hhl), rarely in combination of a bipyramid and tetragonal prism (h00). Indumentum of involucral bracts of X. cylindraceum consists of nonglandular and glandular trichomes. Sylvite (KCl) crystals are observed only on the petal surface of X. cylindraceum. The crystals of sylvite occur in the form of perfect cubes (hexahedrons), but some crystals are deformed, i.e., partially elongated. Taxonomic significance of investigated microcharacters as well as the use of SEM-EDS analysis in taxonomic studies of plants are discussed.


1997 ◽  
Vol 04 (03) ◽  
pp. 559-566 ◽  
Author(s):  
J. M. GIBSON ◽  
X. CHEN ◽  
O. POHLAND

Transmission electron microscopy is uniquely able to extend techniques for imaging free surface steps to the buried interface regime, without significant loss of detail. Two mechanisms for imaging surface and interfacial steps by transmission electron microscopy are described. They are thickness contrast and strain contrast. The former reveals the position and approximate height of steps, whereas the latter detects stress fields which are commonly associated with steps. The basis for each of these methods is elaborated, and preliminary results are shown for step images at Si/SiO2 interfaces, where measurable stress fields have been directly detected for the first time.


NANO ◽  
2013 ◽  
Vol 08 (05) ◽  
pp. 1350052 ◽  
Author(s):  
BIN ZENG ◽  
XIAOHUA CHEN ◽  
XUTAO NING ◽  
CHUANSHENG CHEN ◽  
HUI LONG

Novel flower-like composite architecture was successfully synthesized by spray drying and post-calcinating method for the first time. Scanning electron microscopy and transmission electron microscopy observations confirmed that reduced graphene oxides/carbon nanotubes hybrid (rGO/CNTs) formed a flower-like micrometer structure and Cu2O , CuO ( Cu x O , x = 1 or 2) nanoparticles were decorated inside them. The photocatalytic properties were further investigated by evaluating the photodegradation of a pollutant methyl orange (MO). The experimental results indicated that this novel architecture enhanced photocatalytic performance with 96.2% decomposition of MO after 25 min in the presence of H 2 O 2 under visible light irradiation, which was much higher than that of Cu x O powders (33.2%). This could be attributed to the more efficient adsorption of MO molecules on flower-like rGO/CNTs and provide a high concentration of MO near to the Cu x O nanoparticles, thus promoting the photocatalytic degradation process.


1994 ◽  
Vol 40 (134) ◽  
pp. 195-197
Author(s):  
E. W. Wolff ◽  
A. P. Reid

AbstractA snow crystal has been successfully collected on to a scanning electron microscope (SEM) stub in central Greenland. It was preserved at liquid-nitrogen temperature for 5 months, prior to examination in the SEM. This is believed to be the first time a snow crystal has been observed directly in the SEM and offers some new experimental methods for understanding crystals and their chemistry.


1979 ◽  
Vol 57 (2) ◽  
pp. 91-99 ◽  
Author(s):  
D. L. Hawksworth

Generic concepts in the Testudinaceae (Ascomycotina, Loculoascomycetes) are reviewed with particular emphasis on the sculpturing of the ascospores which has been examined by scanning electron microscopy (SEM) for the first time. A key to the nine genera accepted in the family is provided of which two are described as new: Ulospora for U. bilgramii comb.nov. (= Zopfia bilgramii D. Hawksw. et al.), the ascospores of which have three to six deep fissures in each cell, and Zopfiofoveola for Z. punctata comb.nov. (= Zopfia punctata D. Hawksw. & C. Booth), with distinctly and regularly foveolate ascospores. One further new combination is made: Rechingeriella boudieri comb.nov. (= Zopfia boudieri Arnaud). The positions of three additional genera referred to the family by earlier authors but which are excluded from it here are also briefly discussed.


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