Okra mucilage powder: a novel functional ingredient with antioxidant activity and antibacterial mode of action revealed by scanning and transmission electron microscopy

2019 ◽  
Vol 55 (2) ◽  
pp. 569-577 ◽  
Author(s):  
Chatmanee Nampuak ◽  
Kullanart Tongkhao
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Antioxidant Activity ◽  
Mode Of Action ◽  
Functional Ingredient ◽  
Transmission Electron

scholarly journals Anticandidal Effects of Thymoquinone: Mode of Action Determined by Transmission Electron Microscopy (TEM)

2016 ◽  
Vol 11 (7) ◽  
pp. 1934578X1601100 ◽  
Author(s):  
Gökalp İşcan ◽  
Arzu İşcan ◽  
Fatih Demirci
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Mode Of Action ◽  
Nigella Sativa ◽  
Bioactive Constituents ◽  
Thin Sections ◽  
Black Cumin ◽  
Transmission Electron ◽  
Black Cumin Seed

Thymoquinone (TQ) is one of the bioactive constituents of black cumin seed ( Nigella sativa L.) oil. It is well known that this natural volatile quinone has remarkable antimicrobial effects, especially against Candida species. Consequently, in this present study TQ was evaluated for its anticandidal effects against 14 different pathogenic Candida strains by using the in vitro, partly modified, microdilution CLSI M27-A2 method. After TQ treatment at the minimum inhibitory concentration (MIC), ultra-thin sections of C. albicans cells were thoroughly evaluated by transmission electron microscopy (TEM). The mode of action of TQ on different Candida cells was elaborated, where their disintegration and disorganization with amorphous nucleus were observed microscopically.

scholarly journals The structure of hair and follicles of mice carrying the naked (N) gene

1982 ◽  
Vol 39 (2) ◽  
pp. 139-148 ◽  
Author(s):  
Kathryn A. Raphael ◽  
R. E. Chapman ◽  
Penelope A. Frith ◽  
Pamela R. Pennycuik
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Light Microscopy ◽  
Growth Phase ◽  
Mode Of Action ◽  
N Gene ◽  
Cortical Cells ◽  
Transmission Electron

SummaryThe hairs and follicles from mice carrying the naked (N) gene have been examined using both scanning and transmission electron microscopy in addition to light microscopy. Fibre cuticle cells and occasionally cortical cells were absent from the follicles of N / + mice when the base of the hair was growing. In N / N follicles there was a frequent lack of both cuticle and cortical cells throughout the growth phase of the follicles. Abnormalities were also observed in the manner in which the synthesized keratin was deposited in the fibres. The possible mode of action of the N gene is discussed in the light of these results.

Biological approaches to characterize the mode of action of two 5-nitroindazolinone prototypes on Trypanosoma cruzi bloodstream trypomastigotes

Parasitology ◽  
2016 ◽  
Vol 143 (11) ◽  
pp. 1469-1478 ◽  
Author(s):  
CRISTINA FONSECA-BERZAL ◽  
CRISTIANE FRANÇA DA SILVA ◽  
RUBEM F. S. MENNA-BARRETO ◽  
MARCOS MEUSER BATISTA ◽  
JOSÉ A. ESCARIO ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Trypanosoma Cruzi ◽  
Mode Of Action ◽  
Mitochondrial Membrane ◽  
Drug Resistant ◽  
Cellular Mechanisms ◽  
Transmission Electron ◽  
Intracellular Vesicles

SUMMARYThe phenotypic activity of two 5-nitroindazolinones, i.e. 2-benzyl-1-propyl (22) and 2-benzyl-1-butyl (24) derivatives, previously proposed as anti-Trypanosoma cruzi prototypes, was presently assayed on bloodstream trypomastigotes (BT) of the moderately drug-resistant Y strain. Further exploration of putative targets and cellular mechanisms involved in their activity was also carried out. Therefore, transmission electron microscopy, high-resolution respirometry and flow cytometry procedures were performed on BT treated for up to 24 h with the respective EC50 value of each derivative. Results demonstrated that although 22 and 24 were not as active as benznidazole in this in vitro assay on BT, both compounds triggered important damages in T. cruzi that lead to the parasite death. Ultrastructural alterations included shedding events, detachment of plasma membrane and nuclear envelope, loss of mitochondrial integrity, besides the occurrence of a large number of intracellular vesicles and profiles of endoplasmic reticulum surrounding cytoplasmic organelles such as mitochondrion. Moreover, both derivatives affected mitochondrion leading to this organelle dysfunction, as reflected by the inhibition in oxygen consumption and the loss of mitochondrial membrane potential. Altogether, the findings exposed in the present study propose autophagic processes and mitochondrial machinery as part of the mode of action of both 5-nitroindazolinones 22 and 24 on T. cruzi trypomastigotes.

scholarly journals Polymer Capped Silver Nanoparticles from Ziziphus nummularia Leaves Extract: Potent Antibacterial and Antioxidant Activity

2021 ◽  
Vol 18 (4) ◽  
pp. 691-701
Author(s):  
Faruk Arodiya ◽  
Chirag Makvana ◽  
Kokila Parmar
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Antioxidant Activity ◽  
Silver Nanoparticles ◽  
Fourier Transform ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Ziziphus Nummularia ◽  
Antimicrobial And Antioxidant Activity

Generally, synthesis and encapsulation process improve therapeutic value of nano encapsulated drugs. The silver nanoparticles (AgNPs) biosynthesized from Ziziphus nummularia leaves and encapsulated with polyvinyl pyrrolidone (PVP) polymer as antibacterial agents, due to its high bioavailability, better encapsulation and less toxic properties. The nanoparticles (AgNPs) biosynthesized from Ziziphus nummularia leaves and capped with polyvinyl pyrrolidone (PVP) polymer, The acquired AgNPs and polymeric functionalized AgNPs were fully characterised by the UV- Visible spectroscopy , Transmission electron microscopy (TEM), X-Ray diffraction pattern (XRD) and Fourier transform infrared spectroscopy (FTIR).The crystalline Ag NPs and Polymer Functionalized AgNPs have a face-centered cubic structure with an average size of 9.20 nm, according to X-ray Diffraction spectroscopy. Fourier Transform Infrared spectroscopy revealed that biomolecules such as proteins are incapable of reducing metal ions and the formation of an encapsulating layer in terms of metal ions. High-Resolution transmission electron microscopy revealed that Polymer functionalized AgNPs ranged in size of 10 nm. AgNPs and Polymer functionalized AgNPs showed effective antimicrobial and antioxidant activity. The biosynthesized monodisperse silver nanoparticles and encapsulated silver nanoparticles demonstrated better antimicrobial and antioxidant activity which can be used in various biomedical applications.

Techniques for Transmission Electron Microscopy of Fiber-Matrix Interfaces in Aluminum Alloy-Boron Composites by Ion Erosio

1971 ◽  
Vol 29 ◽  
pp. 204-205
Author(s):  
G. G. Shaw
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Aluminum Alloy ◽  
Electron Beam ◽  
Pure Aluminum ◽  
Ion Milling ◽  
Transmission Electron ◽  
Fiber Matrix ◽  
Ion Erosion ◽  
Row Of Fibers

The morphology and composition of the fiber-matrix interface can best be studied by transmission electron microscopy and electron diffraction. For some composites satisfactory samples can be prepared by electropolishing. For others such as aluminum alloy-boron composites ion erosion is necessary.When one wishes to examine a specimen with the electron beam perpendicular to the fiber, preparation is as follows: A 1/8 in. disk is cut from the sample with a cylindrical tool by spark machining. Thin slices, 5 mils thick, containing one row of fibers, are then, spark-machined from the disk. After spark machining, the slice is carefully polished with diamond paste until the row of fibers is exposed on each side, as shown in Figure 1.In the case where examination is desired with the electron beam parallel to the fiber, preparation is as follows: Experimental composites are usually 50 mils or less in thickness so an auxiliary holder is necessary during ion milling and for easy transfer to the electron microscope. This holder is pure aluminum sheet, 3 mils thick.

Direct Observation of Heat Exchanger Deposits by Cross Sectioning

1967 ◽  
Vol 25 ◽  
pp. 364-365
Author(s):  
R. W. Anderson ◽  
D. L. Senecal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Heat Exchanger ◽  
Direct Observation ◽  
Cross Sections ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Flowing Water ◽  
Transmission Electron ◽  
Deposit Layer

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

Comparative Microstructures of Ion Milled and Electrochemically Thinned Composite Materials

1974 ◽  
Vol 32 ◽  
pp. 546-547
Author(s):  
R.R. Russell
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Composite Materials ◽  
Great Difficulty ◽  
Ion Milling ◽  
Transmission Electron ◽  
Ion Damage ◽  
Intermetallic Composite

Transmission electron microscopy of metallic/intermetallic composite materials is most challenging since the microscopist typically has great difficulty preparing specimens with uniform electron thin areas in adjacent phases. The application of ion milling for thinning foils from such materials has been quite effective. Although composite specimens prepared by ion milling have yielded much microstructural information, this technique has some inherent drawbacks such as the possible generation of ion damage near sample surfaces.

Maytansine-Induced Mitotic Arrest in Human Lymphoblasts

1977 ◽  
Vol 35 ◽  
pp. 460-461
Author(s):  
Tai-Te Chao ◽  
John Sullivan ◽  
Awtar Krishan
Keyword(s):  
Electron Microscopy ◽  
Cell Cycle ◽  
Transmission Electron Microscopy ◽  
Tubulin Polymerization ◽  
Vinca Alkaloids ◽  
Antimitotic Activity ◽  
Transmission Electron ◽  
Flow Microfluorometry ◽  
Brain Tubulin

Maytansine, a novel ansa macrolide (1), has potent anti-tumor and antimitotic activity (2, 3). It blocks cell cycle traverse in mitosis with resultant accumulation of metaphase cells (4). Inhibition of brain tubulin polymerization in vitro by maytansine has also been reported (3). The C-mitotic effect of this drug is similar to that of the well known Vinca- alkaloids, vinblastine and vincristine. This study was carried out to examine the effects of maytansine on the cell cycle traverse and the fine struc- I ture of human lymphoblasts.Log-phase cultures of CCRF-CEM human lymphoblasts were exposed to maytansine concentrations from 10-6 M to 10-10 M for 18 hrs. Aliquots of cells were removed for cell cycle analysis by flow microfluorometry (FMF) (5) and also processed for transmission electron microscopy (TEM). FMF analysis of cells treated with 10-8 M maytansine showed a reduction in the number of G1 cells and a corresponding build-up of cells with G2/M DNA content.

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