scholarly journals Morphological characteristics and cell viability of coffee plants calli

2014 ◽  
Vol 44 (4) ◽  
pp. 660-665 ◽  
Author(s):  
Marlúcia Souza Pádua ◽  
Luciano Vilela Paiva ◽  
Luciano Coutinho da Silva ◽  
Kalynka Gabriella do Livramento ◽  
Eduardo Alves ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Viability ◽  
Coffea Arabica ◽  
Morphological Characteristics ◽  
Leaf Explants ◽  
Transmission Electron ◽  
Different Types ◽  
Coffee Plants ◽  
Cytoplasm Vacuolization

The aim of this research was to characterize and compare two types of calli from leaf explants of Coffea arabica (cultivar Catiguá). Cells of different types of callus were successfully characterized regarding viability and internal and external morphological characteristics. It was obtained two morphologically distinct types of callus: (i) yellow friable and (ii) transparent watery. The yellow friable calli showed higher cell viability and embryogenic characteristics. Scanning and transmission electron microscopy showed embryogenic characteristics in cells of the yellow friable calli evidenced by the presence of small and isodiametric cells, while transparent watery calli showed elongated cells and large cytoplasm vacuolization.

The influence of Pt and SrTiO3 interlayers on the microstructure of PbTiO3 thin films deposited by laser ablation on (001) MgO

1995 ◽  
Vol 10 (4) ◽  
pp. 791-794 ◽  
Author(s):  
S. Stemmer ◽  
S.K. Streiffer ◽  
W-Y. Hsu ◽  
F. Ernst ◽  
R. Raj ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Laser Ablation ◽  
Volume Fraction ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Transmission Electron ◽  
Electrical Conductivities ◽  
Different Types ◽  
Oriented Material

We have used conventional and high-resolution transmission electron microscopy to investigate the microstruture of epitaxial, ferroelectric PbTiO3 films grown by pulsed laser ablation on (001) MgO single crystals, and on MgO covered with epitaxial Pt or SrTiO3. Pronounced variations are found in the widths and lengths of a-axis-oriented domains in these films, although the volume fraction of a-axis-oriented material varies only weakly for the different types of samples. In addition, the films deposited onto Pt-coated MgO have a larger grain size than those deposited onto bare MgO or SrTiO3/MgO. Possible reasons for the variations in the distribution of a-axis-oriented material in these samples include differences in the elastic properties and electrical conductivities of the different substrate combinations.

High Resolution Transmission Electron Microscope Study of Amorphous and Partially Crystalline Fe7 8B1 3Si9 Alloy

1985 ◽  
Vol 58 ◽  
Author(s):  
A.R. Bhatti ◽  
J.C. Barry ◽  
B Cantor
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Electron Microscope Study ◽  
Lattice Imaging ◽  
Transmission Electron ◽  
Different Types ◽  
Mean Size ◽  
Transmission Electron Microscope Study ◽  
Imaging Mode

ABSTRACTAmorphous and partially crystalline Fe7 8B1 3 Si9 alloys have been examined by high resolution transmission electron microscopy at 200kV. In lattice imaging mode, the as-quenched alloy shows small regions, with a mean size of - 20Å, consisting of well defined patterns of fringes. Three different types of crystals can be identified at the very earliest stages of crystallisation of the alloy.

scholarly journals Morphological aspects of cell reabsorption in laying queens and workers of Apis mellifera (Hymenoptera, Apidae)

2008 ◽  
Vol 98 (4) ◽  
pp. 421-424 ◽  
Author(s):  
Karina Patrício ◽  
Carminda da Cruz-Landim
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Apis Mellifera ◽  
Environmental Factors ◽  
Developmental Stage ◽  
Oocyte Maturation ◽  
Morphological Characteristics ◽  
Follicular Cells ◽  
Morphological Aspects ◽  
Transmission Electron

The occurrence of cell reabsorption in the ovaries of queens in several rates of laying eggs, artificially impeded of laying, and in nurse workers, of Apis mellifera (Linnaeus, 1758), was studied with light (LM) and transmission electron microscopy (TEM). Two types of structures were described and named by analogy with vertebrates ovarian structures, as corpus luteus, when resulting from the reabsorption of the follicular cells after ovulation, and corpus atresicus when resulting from total follicular reabsorption at any oocyte developmental stage. These structures have the same morphological characteristics and physiological signification in both castes. The corpus luteus occurrence indicates ovulation and its number is correspondent to the queen's rates of oviposition. The presence of this structure in nurse workers ovarioles shows that this caste may lay eggs. The incidence of corpus atresicus in queens decay with the increasing of the oviposition indicating that the inhibition of the normal sequence of oocyte maturation in the ovaries is deleterious. Both, corpus luteus and corpus atresicus incidence may be influenced by environmental factors.

scholarly journals Protective Effect of Astragaloside IV on Hepatic Injury Induced by Iron Overload

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Dongyu Xie ◽  
Ping Zhou ◽  
Lin Liu ◽  
Wenjing Jiang ◽  
Haina Xie ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Iron Overload ◽  
Cell Viability ◽  
Liver Damage ◽  
Therapeutic Drug ◽  
Iron Dextran ◽  
Astragaloside Iv ◽  
Apoptosis Rate ◽  
Transmission Electron

Suitable content of iron is essential for human body, but iron overload is associated with many kinds of diseases including chronic liver damage. Recently, researchers find that iron overload promotes hepatocyte autophagy and apoptosis. However, the mechanism of iron overload in liver damage remains unclear. In this study, Lo2 cells were selected as the research object, iron dextran was a model drug, and astragaloside IV was a therapeutic drug to explore the role of iron overload. MTT assay and Annexin/PI double staining were used to measure cell viability and apoptosis. Ultrastructure was observed by transmission electron microscopy. The expression levels of apoptosis and autophagy-related proteins were determined by real-time PCR and Western Blot. The results showed that iron dextran could significantly inhibit Lo2 cell viability and increase the apoptosis rate, while astragaloside IV could reverse the inhibition of Lo2 cell viability and decrease the apoptosis rate. Transmission electron microscopy showed a significant increase in the number of autophagosomes after administration of iron dextran, and the application of astragaloside IV reduced the production of autophagosomes. LC3II/I was significantly upregulated in the model group but decreased in the astragaloside IV treatment group, and P62 showed the opposite trend. Iron dextran significantly upregulated the expression of Bax and downregulated Bcl2, while astragaloside IV reversed this trend. Finally, the inhibition of hepcidin caused by iron dextran was counteracted by astragaloside IV. In conclusion, the experimental results show that the iron overload model mainly induces excessive autophagy and apoptosis of hepatocytes, thus causing damage to hepatocytes, but astragaloside IV plays a certain therapeutic role in reversing this damage.

Polymorphism of microtriches in the cysticercoid of Ophryocotyle insignis Lonnberg, 1890 from the limpet Patella vulgata

1983 ◽  
Vol 61 (5) ◽  
pp. 1062-1070 ◽  
Author(s):  
Barbara M. MacKinnon ◽  
Michael D. B. Burt
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Anterior Margin ◽  
Transverse Section ◽  
External Surface ◽  
Larval Body ◽  
Patella Vulgata ◽  
Transmission Electron ◽  
Different Types

The mature cysticercoid of Ophryocotyle insignis, from Patella vulgata, was examined using transmission electron microscopy. Eight different types of microtriches were present over the tegument of the larval body and microvilli covered the caudal bladder, or cercomer. Rounded, modified microtriches were present on the external surface of the bladder enclosing the cysticercoid. Microtriches lining the retraction chamber ranged from small triangular projections having an electron-dense ridge along the anterior margin but having no shaft, to more typically shaped, larger microtriches having a cytoplasmic base, electron-dense shaft, and an electron-dense ridge along the anterior margin of the base. The scolex tegument had large robust microtriches which, in transverse section, had many projecting flanges. The microtriches on the rostellum were long and slender. Long, thin microtriches were present amongst the small spines on the suckers and short microtriches were found on the unspined areas of the suckers. Possible functions for the different types of microtriches are suggested and the significance of microvilli on the cercomer is discussed.

Structural and morphological variations of encapsulated metal oxides in single walled carbon nanotubes

2005 ◽  
Vol 901 ◽  
Author(s):  
Pedro MFJ Costa ◽  
Narun Thamavaranukup ◽  
Thomas Rutherford ◽  
Steffi Friedrichs ◽  
Jeremy Sloan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Transmission Electron Microscopy ◽  
Metal Oxides ◽  
Morphological Characteristics ◽  
Single Walled Carbon Nanotubes ◽  
Morphological Variations ◽  
Single Walled Carbon ◽  
Transmission Electron ◽  
Walled Carbon Nanotubes

AbstractSingle walled carbon nanotubes have been filled with a variety of metal oxides and the structural and morphological characteristics of the metal_oxide@SWNT composites studied. Advanced techniques of software aberrations correction for transmission electron microscopy were used for characterisation. This research shows that, despite their higher reactivity compared to salts such as halides, oxides can be encapsulated within SWNTs with some compounds attaining remarkable filling yields.

Cdc20 protects cells from Ara-c-induced apoptosis in AML via targeting  autophagy

2021 ◽  
Author(s):  
Shumin Ding ◽  
Jinyao Kan ◽  
Yan Wang ◽  
Siyuan Cui ◽  
Jingyi Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Viability ◽  
Western Blotting ◽  
Ros Generation ◽  
Apoptosis Rate ◽  
Rate Expression ◽  
Transmission Electron ◽  
Induced Apoptosis

Abstract ObjectiveThis study aims to explore the role and mechanism of Cdc20 on Ara-c chemosensitivity of AML cells.MethodsEvaluation experiments of effects of Cdc20 on Ara-c chemosensitivity were performed with AML cell transfected with constructs overexpressing Cdc20 or AML cell transfected with Cdc20 shRNA through observing cell viability, apoptosis rate,expression of apoptosis protein.The level of autophagy was assessed by transmission electron microscopy and western blotting.ResultsAfter exposure to Ara-c, Cdc20 expression is down-regulated. Intracellular Cdc20 expression inhibited Ara-c-induced apoptosis as shown by increasing cell viability and decreasing expression of cleaved caspase3.The expression of LC3B was mediated by Cdc20 expression,which further inhibits autophagy. Moreover, Cdc20 mediated LC3B-decreasing promotes the expression of P-Akt and P-ERK and inhibits ROS generation.ConclusionIt was determined that Cdc20 promoted the degradation of LC3B, thereby inhibiting autophagy and decreasing Ara-c-induced apoptosis in AML cells.

Visualisation of Electrically Active Areas Using Electron Holography

2002 ◽  
Author(s):  
U. Muehle ◽  
A. Lenk ◽  
M. Lehmann ◽  
H. Lichte
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Sample Preparation ◽  
Electron Holography ◽  
Transmission Electron ◽  
Structural Details ◽  
Different Types ◽  
High Level ◽  
Technical Solutions

Abstract In accordance with the predictions of the International Semiconductor Association, a further decrease in the structural widths of semiconductor devices is expected. For an in-depth characterization of actual structural details, the transmission electron microscopy (TEM)-technique is becoming more and more significant. An urgent requirement is in the visualization of dimensions of the doped regions and estimation of p-n-junctions profile with a high level spatial resolution. The off-axis electron holography, a special TEM-technique, is able to visualize electrically active areas in semiconductors. This article describes a way to achieve sample preparation for TEM-holography from actual memory products and also provides an idea of the potential of this technique for semiconductor failure analysis. It shows that different types and sizes of FET's and testing structures could be visualized by focusing on the physical basics, technical solutions, and sample preparation.

scholarly journals Characterization of mouse spermatogonia by transmission electron microscopy

Reproduction ◽  
2002 ◽  
pp. 567-577 ◽  
Author(s):  
H Chiarini-Garcia ◽  
LD Russell
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
B Cells ◽  
Nuclear Envelope ◽  
Type B ◽  
Intermediate Type ◽  
Functional Studies ◽  
Transmission Electron ◽  
Different Types

Characteristics of the various type A, intermediate (In) and B spermatogonia were determined in C57BL/6J mice using transmission electron microscopy. Spermatogonia were photographed at all stages of the cycle of the seminiferous epithelium. Over 450 images were taken. Spermatogonia could be classified into As, Apr, Aal, A1 cells, A2 cells, A3 cells, A4 cells, intermediate type and type B cells primarily on the basis of nuclear and nucleolar characteristics. The most primitive spermatogonia (As, Apr, Aal) had mottled chromatin; A1 cells contained homogeneously finely granular chromatin throughout the nucleus; A2, A3, A4 and intermediate type spermatogonia had progressively increasing amounts of chromatin encrusting the nuclear envelope; type B spermatogonia had less heterochromatin along the nuclear envelope, although the particles were more dense and rounded than in intermediate type spermatogonia. Mitochondrial size and position of Golgi complexes varied in different types of spermatogonia. These data show that types of spermatogonia can be differentiated such that these characteristics can be used in functional studies.

scholarly journals Effects of physical training on sarcomere lengths and muscle-tendon interface of the cervical region in an experimental model of menopause

2019 ◽  
Vol 63 (3) ◽  
Author(s):  
Carolina dos Santos Jacob ◽  
Lara Caetano Rocha ◽  
Jurandyr Pimentel Neto ◽  
Ii-sei Watanabe ◽  
Adriano Polican Ciena
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Experimental Model ◽  
Wistar Rats ◽  
Morphological Characteristics ◽  
Cervical Region ◽  
Myotendinous Junction ◽  
Swimming Training ◽  
Transmission Electron ◽  
Tissue Reorganization

The aim of this study was to describe the structural and ultrastructural aspects of the myotendinous junction (MTJ) and the proximal and distal sarcomeres of the sternomastoid of aged Wistar rats subjected to an experimental model of menopause and swimming training. A total of 20 female elderly rats were divided into the following four groups (n=5 in each group): sedentary/no-menopausal (SNM), trained/no-menopausal (TNM), sedentary/menopausal (SM), and trained/menopausal (TM). The MTJ samples were dissected and analyzed using transmission electron microscopy. We showed that the TNM Group rats exhibited changes in morphological characteristics as a consequence of physical exercise, which included an increase of 36.60% (P<0.001) in the evagination length of the MTJ and a reduction in the length of the distal (77.38%) (P<0.0001) and proximal (68.15%) (P<0.0001) sarcomeres. The SM Group exhibited a reduction of about 275.93% (P<0.001) in the muscle-tendon interface and in the lengths of distal sarcomeres (55.87%) (P<0.0001) compared with SNM Group. Our results suggest that the swimming training under experimental model of menopause promoted tissue reorganization and increased muscle-tendon interaction with a drastic development in the length and thickness of the sarcoplasmatic invaginations and evaginations. In addition, the sarcomeres exhibited different lengths and a reduction in both groups subjected to swimming training.

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