scholarly journals Cellular Calcium Distribution Modulates the Growth of Callus and Protoplasts of Halophyte Mangrove Plant, Avicennia Alba - an X-ray Microanalysis

2017 ◽  
Vol 6 (2) ◽  
pp. 18
Author(s):  
Manabu Hayatsu ◽  
Suechika Suzuki ◽  
Shinpei Tsuchiya ◽  
Hamako Sasamoto
Keyword(s):  
Cell Wall ◽  
Culture Medium ◽  
Middle Lamella ◽  
Mangrove Plant ◽  
Callus Line ◽  
Cytoplasmic Matrix ◽  
X Ray ◽  
Low Concentrations ◽  
Avicennia Alba ◽  
Cellular Ca

Two cultured cell lines were developed from cotyledons of a halophyte mangrove, Avicennia alba.In the high-Ca callus line, which was sub-cultured in amodified amino acid medium containing 3 mM CaCl2, growth of calluses and their protoplasts were both inhibited by low concentrations of CaCl2 in the culture medium. Removal of Ca2+ from the culture medium stimulated callus growth and the calluses could be sub-cultured without CaCl2 (low-Ca callus line). The intra- (cytoplasmic matrix and vacuole) and extra- (cell wall) cellular concentrations of elements, i.e., [Ca], [K], [Cl], [Na], [Mg], [P] and [S] were investigated using quantitative X-ray microanalysis of cryosections of calluses from bothcell lines. [Ca] was high in the cytoplasmic matrix and cell wall of the high-Ca line. [Ca] was lowered in the low-Calineinall cell compartments, though still detected. Ca-containing electron-dense precipitates were accumulated in the middle lamella of cell walls in resin-embedded sections of the high-Ca line. CaCl2 in the medium stimulated protoplast growth only in the low-Caline. These results suggested that a low cellular [Ca] is needed for protoplasts growth of A. alba. The importance of cellular [Ca] for the growth of halophilic mangrove plant cells was discussed.

scholarly journals Ultrastructure of Cells and Microanalysis in Malus domestica Borkh. ‘Szampion’ Fruit in Relation to Varied Calcium Foliar Feeding

Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4622
Author(s):  
Piotr Kowalik ◽  
Tomasz Lipa ◽  
Zenia Michałojć ◽  
Mirosława Chwil
Keyword(s):  
Cell Wall ◽  
Malus Domestica ◽  
Cell Structure ◽  
Middle Lamella ◽  
Apple Fruit ◽  
Malus Domestica Borkh ◽  
X Ray ◽  
Transmission Electron ◽  
Cytoplasmic Membranes

Calcium is one of the most poorly reutilized nutrients. Its deficiencies cause various physiological disturbances and, consequently, reduce the quantity and quality of yields. Reduced content of Ca2+ ions in cells leads to development of, e.g., bitter pit in apples. Efficient and instantaneous mitigation of Ca2+ deficiencies is provided by foliar feeding. There are no detailed data on the effect of foliar feeding with various calcium forms on the cell structure or on the microanalysis and mapping of this element in apple fruit cells. Therefore, we carried out comparative studies of the ultrastructure of epidermis and hypodermis cells, to assess the content and distribution of calcium in the cell wall, cytoplasmic membrane, cytoplasm, and precipitates of Malus domestica Borkh. ‘Szampion’ fruit exposed to four Ca treatments, including the control with no additional Ca supplementation (I) and foliar applications of Ca(NO3)2 (II), CaCl2 (III), and Ca chelated with EDTA (IV). Light and transmission electron microscopy and an X-ray microanalyzer were used and showed a beneficial effect of calcium preparations on the ultrastructure of fruit epidermis and hypodermis cells, manifested in the presence of a normally developed cell wall with a regular middle lamella, preserved continuity of cytoplasmic membranes, and stabilized cell structure. In the selected elements of apical epidermis cells, the highest level of Ca2+ ions was detected in the middle lamella, cell wall, plasmalemma, and cytoplasm. The highest increase in the Ca2+ content in these cell constituents was recorded in treatment IV, whereas the lowest value of the parameters was noted in variant III.

The topochemistry of black spruce sulphonation: A TEM/EDXA study

1983 ◽  
Vol 41 ◽  
pp. 710-711
Author(s):  
R.P. Beatson ◽  
C. Gancet ◽  
C. Heitner
Keyword(s):  
Cell Wall ◽  
Significant Influence ◽  
Background Subtraction ◽  
Black Spruce ◽  
Middle Lamella ◽  
Wood Chips ◽  
Factors Affecting ◽  
X Ray ◽  
Spruce Wood ◽  
Carbon Coated

Pulps produced by mechanical defibration of sulphite treated black spruce wood chips contain large amounts of lignin. The degree of sulphonation of this lignin has a significant influence on the physical properties of handsheets made from the resulting pulps In earlier work we have described the factors affecting the sulphonation of black spruce.The aim of the present investigation was to determine the differences in reactivity of sulphite towards lignin in the middle lamella and cell wall of black spruce.Black spruce wood chips were well impregnated with sodium base sulphite solutions having pH 7, and then heated at 140° and 80°C for known times. The resulting sulphonated wood chips were cut into small sticks and embedded in Vestopal. Transverse sections, 150 nm thick, were placed on a carbon grid having a single 1 mm hole bearing a collodian film which had been carbon coated. Sulphur contents in the middle lamella and cell wall were determined with a Philips 400 TEM coupled with an EDAX 9100/60 analyser. The concentration of sulphur was taken to be proportional to the x-ray counts in the sulphur Kα window after background subtraction, as shown in Figure 1.

Microtubule nucleation sequence studied by time-resolved x-ray scattering and electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 766-767
Author(s):  
Eva-Maria Mandelkow ◽  
Eckhard Mandelkow ◽  
Joan Bordas
Keyword(s):  
Electron Microscopy ◽  
Dynamic Equilibrium ◽  
Time Resolved ◽  
X Ray ◽  
Additional Information ◽  
X Ray Scattering ◽  
Low Concentrations ◽  
Microtubule Growth ◽  
Ray Patterns ◽  
Ray Scattering

When a solution of microtubule protein is changed from non-polymerising to polymerising conditions (e.g. by temperature jump or mixing with GTP) there is a series of structural transitions preceding microtubule growth. These have been detected by time-resolved X-ray scattering using synchrotron radiation, and they may be classified into pre-nucleation and nucleation events. X-ray patterns are good indicators for the average behavior of the particles in solution, but they are difficult to interpret unless additional information on their structure is available. We therefore studied the assembly process by electron microscopy under conditions approaching those of the X-ray experiment. There are two difficulties in the EM approach: One is that the particles important for assembly are usually small and not very regular and therefore tend to be overlooked. Secondly EM specimens require low concentrations which favor disassembly of the particles one wants to observe since there is a dynamic equilibrium between polymers and subunits.

The CM120 Biotwin: a high-contrast objective lens, optimum cryo-vacuum and improved EDX performance

1995 ◽  
Vol 53 ◽  
pp. 584-585
Author(s):  
Uwe Lücken ◽  
Michael Felsmann ◽  
Wim M. Busing ◽  
Frank de Jong
Keyword(s):  
Life Science ◽  
Focal Length ◽  
Objective Lens ◽  
High Contrast ◽  
Contrast Imaging ◽  
X Ray ◽  
Forming Mechanism ◽  
Similar Image ◽  
High Contrast Imaging ◽  
Low Concentrations

A new microscope for the study of life science specimen has been developed. Special attention has been given to the problems of unstained samples, cryo-specimens and x-ray analysis at low concentrations.A new objective lens with a Cs of 6.2 mm and a focal length of 5.9 mm for high-contrast imaging has been developed. The contrast of a TWIN lens (f = 2.8 mm, Cs = 2 mm) and the BioTWTN are compared at the level of mean and SD of slow scan CCD images. Figure 1a shows 500 +/- 150 and Fig. 1b only 500 +/- 40 counts/pixel. The contrast-forming mechanism for amplitude contrast is dependent on the wavelength, the objective aperture and the focal length. For similar image conditions (same voltage, same objective aperture) the BioTWIN shows more than double the contrast of the TWIN lens. For phasecontrast specimens (like thin frozen-hydrated films) the contrast at Scherzer focus is approximately proportional to the √ Cs.

Ultrastructure and Senescence in an Achloroplastic Mutant of Hordeum vulgare L. cv. Dyan

1992 ◽  
Vol 50 (1) ◽  
pp. 844-845
Author(s):  
R.H.M. Cross ◽  
C.E.J. Botha ◽  
A.K. Cowan ◽  
B.J. Hartley
Keyword(s):  
Cell Wall ◽  
Hordeum Vulgare ◽  
Leaf Tissue ◽  
Ultrastructural Changes ◽  
Hordeum Vulgare L ◽  
Mesophyll Cells ◽  
Lethal Mutant ◽  
Cytoplasmic Matrix ◽  
Close Proximity ◽  
Pinocytotic Vesicles

Senescence is an ordered degenerative process leading to death of individual cells, organs and organisms. The detection of a conditional lethal mutant (achloroplastic) of Hordeum vulgare has enabled us to investigate ultrastructural changes occurring in leaf tissue during foliar senescence.Examination of the tonoplast structure in six and 14 day-old mutant tissue revealed a progressive degeneration and disappearance of the membrane, apparently starting by day six in the vicinity of the mitochondria associated with the degenerating proplastid (Fig. 1.) where neither of the plastid membrane leaflets is evident (arrows, Fig. 1.). At this stage there was evidence that the mitochondrial membranes were undergoing retrogressive changes, coupled with disorganization of cristae (Fig. 2.). Proplastids (P) lack definitive prolamellar bodies. The cytoplasmic matrix is largely agranular, with few endoplasmic reticulum (ER) cisternae or polyribosomal aggregates. Interestingly, large numbers of actively-budding dictysomes, associated with pinocytotic vesicles, were observed in close proximity to the plasmalemma of mesophyll cells (Fig. 3.). By day 14 however, mesophyll cells showed almost complete breakdown of subcellular organelle structure (Fig. 4.), and further evidence for the breakdown of the tonoplast. The final stage of senescence is characterized by the solubilization of the cell wall due to expression and activity of polygalacturonase and/or cellulose. The presence of dictyosomes with associated pinocytotic vesicles formed from the mature face, in close proximity to both the plasmalemma and the cell wall, would appear to support the model proposed by Christopherson for the secretion of cellulase. This pathway of synthesis is typical for secretory glycoproteins.

Silicification of wood-cell walls

1994 ◽  
Vol 52 ◽  
pp. 428-429
Author(s):  
S. E. Keckler ◽  
D. M. Dabbs ◽  
N. Yao ◽  
I. A. Aksay
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Cell Walls ◽  
Lignin Content ◽  
Resin Composite ◽  
Middle Lamella ◽  
Cellulose Fibers ◽  
Complex Structures ◽  
Rich Region ◽  
Inorganic Precursors

Cellular organic structures such as wood can be used as scaffolds for the synthesis of complex structures of organic/ceramic nanocomposites. The wood cell is a fiber-reinforced resin composite of cellulose fibers in a lignin matrix. A single cell wall, containing several layers of different fiber orientations and lignin content, is separated from its neighboring wall by the middle lamella, a lignin-rich region. In order to achieve total mineralization, deposition on and in the cell wall must be achieved. Geological fossilization of wood occurs as permineralization (filling the void spaces with mineral) and petrifaction (mineralizing the cell wall as the organic component decays) through infiltration of wood with inorganics after growth. Conversely, living plants can incorporate inorganics into their cells and in some cases into the cell walls during growth. In a recent study, we mimicked geological fossilization by infiltrating inorganic precursors into wood cells in order to enhance the properties of wood. In the current work, we use electron microscopy to examine the structure of silica formed in the cell walls after infiltration of tetraethoxysilane (TEOS).

Localization of calcium and zinc in the sperm storage tubules of chicken, quail and turkey using X-ray microanalysis

Reproduction ◽  
2000 ◽  
pp. 331-336 ◽  
Author(s):  
L Holm ◽  
H Ekwall ◽  
GJ Wishart ◽  
Y Ridderstrale
Keyword(s):  
Calcium Concentration ◽  
Sperm Storage ◽  
X Ray ◽  
Elemental Concentrations ◽  
Low Concentrations ◽  
Intracellular Content ◽  
Wet Weight ◽  
The Mean ◽  
Sperm Storage Tubules ◽  
Scanning Electron

Sperm storage tubules from the utero-vaginal junction of chickens, quails and turkeys were analysed for calcium and zinc using X-ray microanalysis of ultra-rapidly frozen tissue in a scanning electron microscope. This technique enabled the tubular fluid surrounding the stored spermatozoa and the intracellular content of the cells of the sperm storage tubules to be analysed separately and, by using standards with known concentrations, their elemental concentrations were estimated. The mean (+/- SEM) concentration of calcium in the tubular fluid from chickens, quails and turkeys was 17 +/- 3, 19 +/- 3 and 17 +/- 4 mmol kg(-1) wet weight, respectively. The intracellular calcium concentration of the cells of the tubules did not differ significantly from these values and was also similar in the mucosal epithelial cells of the utero-vaginal junction. Zinc was localized in the cells of turkey sperm storage tubules and tubular fluid, but at low concentrations. No zinc could be detected in corresponding structures from chickens and quails. The concentration of calcium in the tubular fluid is within the range known to inhibit the motility of spermatozoa, supporting this function for calcium during storage. Zinc is known to depress turkey sperm metabolism and it may also be involved in inducing quiescence of spermatozoa during storage in this species.

Adsorption Capacity of Y Zeolite Using Organic Solvents such as Adsorbates

2014 ◽  
Vol 805 ◽  
pp. 641-645
Author(s):  
Ana Paula Araújo ◽  
Aline Cadigena Lima Patrício ◽  
Anna Karoline Freires de Sousa ◽  
Mariaugusta Ferreira Mota ◽  
Meiry Glaúcia Freire Rodrigues
Keyword(s):  
Small Molecules ◽  
Adsorption Capacity ◽  
Selective Adsorption ◽  
X Ray Diffraction ◽  
Y Zeolite ◽  
High Adsorption ◽  
X Ray ◽  
Low Concentrations ◽  
Adsorption Of Nitrogen ◽  
Type Zeolite

The zeolites differ from traditional adsorbents for selective adsorption of small molecules, the high adsorption capacity at low concentrations and affinity for organic compounds and unsaturated polar molecules. In this work a Y-type zeolite was synthesized, characterized by x-ray diffraction, scanning electron microscopy and adsorption of nitrogen and subjected to test adsorption capacity where it was found that the Y zeolite has the potential adsorption capacity compared to other materials being studied and marketed.

scholarly journals A Novel Synthetic UV-Curable Fluorinated Siloxane Resin for Low Surface Energy Coating

Polymers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 979 ◽  
Author(s):  
Chunfang Zhu ◽  
Haitao Yang ◽  
Hongbo Liang ◽  
Zhengyue Wang ◽  
Jun Dong ◽  
...  
Keyword(s):  
Surface Energy ◽  
Photoelectron Spectroscopy ◽  
Contact Angles ◽  
Proton Nuclear Magnetic Resonance ◽  
Energy Materials ◽  
Uv Curable ◽  
X Ray ◽  
Low Surface Energy ◽  
Low Concentrations ◽  
Siloxane Polymers

Low surface energy materials have attracted much attention due to their properties and various applications. In this work, we synthesized and characterized a series of ultraviolet (UV)-curable fluorinated siloxane polymers with various fluorinated acrylates—hexafluorobutyl acrylate, dodecafluoroheptyl acrylate, and trifluorooctyl methacrylate—grafted onto a hydrogen-containing poly(dimethylsiloxane) backbone. The structures of the fluorinated siloxane polymers were measured and confirmed by proton nuclear magnetic resonance and Fourier transform infrared spectroscopy. Then the polymers were used as surface modifiers of UV-curable commercial polyurethane (DR-U356) at different concentrations (1, 2, 3, 4, 5, and 10 wt %). Among three formulations of these fluorinated siloxane polymers modified with DR-U356, hydrophobic states (91°, 92°, and 98°) were obtained at low concentrations (1 wt %). The DR-U356 resin is only in the hydrophilic state at 59.41°. The fluorine and siloxane element contents were investigated by X-ray photoelectron spectroscopy and the results indicated that the fluorinated and siloxane elements were liable to migrate to the surface of resins. The results of the friction recovering assays showed that the recorded contact angles of the series of fluorinated siloxane resins were higher than the original values after the friction-annealing progressing.

scholarly journals Acanthamoeba-Campylobacter Coculture as a Novel Method for Enrichment of Campylobacter Species

2007 ◽  
Vol 73 (21) ◽  
pp. 6864-6869 ◽  
Author(s):  
Diana Axelsson-Olsson ◽  
Patrik Ellstr�m ◽  
Jonas Waldenstr�m ◽  
Paul D. Haemig ◽  
Lars Brudin ◽  
...  
Keyword(s):  
Culture Medium ◽  
Bacterial Species ◽  
Oxygen Quenching ◽  
Free Living ◽  
Promising Tool ◽  
Low Concentrations ◽  
Novel Method ◽  
Selective Antibiotics ◽  
Different Sources ◽  
Bacterial Concentrations

ABSTRACT In this study, we present a novel method to isolate and enrich low concentrations of Campylobacter pathogens. This method, Acanthamoeba-Campylobacter coculture (ACC), is based on the intracellular survival and multiplication of Campylobacter species in the free-living protozoan Acanthamoeba polyphaga. Four of the Campylobacter species relevant to humans and livestock, Campylobacter jejuni, C. coli, C. lari, and C. hyointestinalis, were effectively enriched by the coculture method, with growth rates comparable to those observed in other Campylobacter enrichment media. Studying six strains of C. jejuni isolated from different sources, we found that all of the strains could be enriched from an inoculum of fewer than 10 bacteria. The sensitivity of the ACC method was not negatively affected by the use of Campylobacter-selective antibiotics in the culture medium, but these were effective in suppressing the growth of seven different bacterial species added at a concentration of 104 CFU/ml of each species as deliberate contamination. The ACC method has advantages over other enrichment methods as it is not dependent on a microaerobic milieu and does not require the use of blood or other oxygen-quenching agents. Our study found the ACC method to be a promising tool for the enrichment of Campylobacter species, particularly from water samples with low bacterial concentrations.

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