Untangling the hidden intrathalline microalgal diversity in Parmotrema pseudotinctorum: Trebouxia crespoana sp. nov.

2018 ◽  
Vol 50 (3) ◽  
pp. 357-369 ◽  
Author(s):  
Pavel ŠKALOUD ◽  
Patricia MOYA ◽  
Arántzazu MOLINS ◽  
Ondřej PEKSA ◽  
Arnoldo SANTOS-GUERRA ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Canary Island ◽  
Sanger Sequencing ◽  
454 Pyrosequencing ◽  
Wall Thickening ◽  
Vegetative Cells ◽  
Island Populations ◽  
Transmission Electron ◽  
Pyriform Cells

AbstractIntrathalline phycobiont diversity was investigated in a rosette-forming lichen, Parmotrema pseudotinctorum, using a combination of Sanger sequencing, 454-pyrosequencing, conventional light and confocal microscopy, and transmission electron microscopy. A total of 39 thalli sampled in five Canary Island populations were investigated. Three novel lineages of lichen phycobionts were detected, all being inferred within the Trebouxia clade G. The most abundant phycobiont lineage, occurring in all lichen populations investigated, is described here as Trebouxia crespoana sp. nov. This species produces spherical to pyriform cells possessing a crenulate chloroplast with lobes elongated at their ends, and one corticola-type pyrenoid with very thin, unbranched tubules of curved profile. Trebouxia crespoana is clearly distinguished from all other Trebouxia species by a characteristic cap-like cell wall thickening produced on one side of vegetative cells, and the larger size of vegetative cells that reach 21(–26) µm in diameter.

The histology, ultrastructure, and histochemistry of the ventral surfaces of Catatropis verrucosa (Froelich, 1789) Odhner, 1905 and Paramonostomum alveatum (Mehlis in Creplin, 1846) Lühe, 1909 (Digenea: Notocotylidae)

1982 ◽  
Vol 60 (10) ◽  
pp. 2434-2441 ◽  
Author(s):  
Barbara M. MacKinnon
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
The Body ◽  
Transmission Electron ◽  
Unknown Protein ◽  
Pyriform Cells

Catatropis verrucosa (Froelich 1789) Odhner 1905 and Paramonostomum alveatum (Mehlis in Creplin, 1846) Lühe 1909 were examined using light and scanning and transmission electron microscopy. The ventral ridge, papillae, and body margins of C. verrucosa contained numerous pyriform cells packed with mitochondria. Paramonostomum alveatum has no ventral projections and no pyriform cells full of mitochondria were seen within the worms. Both species contained numerous large electron-dense inclusions in various tissues throughout the body. Histochemistry indicated that these inclusions were lipid or lipoprotein, but their function is unknown. Protein, including haemoglobin, and lipid were identified within the pyriform cells of C. alveatum. Paramonostomum is the only genus within the Notocotylinae examined to date that has no ventral projections nor any internal aggregation of cells packed with mitochondria.

The structure and possible function of the ventral papillae of Notocotylus triserialis Diesing, 1839

Parasitology ◽  
1982 ◽  
Vol 84 (2) ◽  
pp. 313-332 ◽  
Author(s):  
Barbara M. MacKinnon
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Alkaline Phosphatase ◽  
Ventral Surface ◽  
Acid Mucopolysaccharide ◽  
Acid And Alkaline Phosphatase ◽  
Transmission Electron ◽  
Histochemical Tests ◽  
Pyriform Cells

SUMMARYNotocotylus triserialis bears three rows of eversible papillae on its ventral surface. These papillae, which in living worms are firmly applied to the host mucosa, contain numerous pyriform cells. Histochemical tests indicate the presence, within the papillar cells, of protein, lipid, haemoglobin and esterase, and the absence of carbohydrate, acid mucopolysaccharide, RNA, haemosiderin and acid and alkaline phosphatase. Transmission electron microscopy shows the tegument of the papillae to be similar to the non-papillar ventral tegument. The pyriform cells contain many mitochondria with numerous cristae. A mechanism is proposed whereby the musculature of the worm effects the retraction and eversion of the ventral papillae.

Wound Tyloses in Robinia Pseudoacacia L.

IAWA Journal ◽  
1994 ◽  
Vol 15 (2) ◽  
pp. 157-160 ◽  
Author(s):  
Uwe Schmitt ◽  
Walter Liese
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Division ◽  
Robinia Pseudoacacia ◽  
Wall Thickening ◽  
Primary Wall ◽  
Transmission Electron ◽  
Mother And Daughter ◽  
Robinia Pseudoacacia L ◽  
Earlywood Vessels

The formation of tyloses in vessels of Robinia pseudoacacia L. after wounding was investigated by transmission electron microscopy. Some tyloses in earlywood vessels exhibit cell division. The young walls between mother and daughter tyloses with primary wall-like appearance evince plasmodesmata; pits develop simultaneously with wall thickening.

Arterial Wall Changes in Cerebral Vasospasm

Neurosurgery ◽  
1989 ◽  
Vol 25 (5) ◽  
pp. 736-746 ◽  
Author(s):  
J. M. Findlay ◽  
B. K. A. Weir ◽  
K. Kanamaru ◽  
F. Espinosa
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Vessel Wall ◽  
Cerebral Arteries ◽  
Fold Increase ◽  
Ultrastructural Changes ◽  
Wall Thickening ◽  
Vessel Wall Thickness ◽  
Transmission Electron

Abstract A right-sided subarachnoid hemorrhage (SAH) was created in 12 monkeys. Only the right (clot-side) cerebral arteries developed angiographic vasospasm (VSP), which was maximal 7 days after SAH. Eight animals were killed at this time and the remainder at 14 days. At the time of killing the middle cerebral arteries (MCAs) were harvested, and four normal, left (non-clot-side) MCAs were vasoconstricted in vitro with prostaglandin F2… All MCAs were studied with scanning and transmission electron microscopy. Right MCAs in maximal VSP 7 days from SAH were undistinguishable on scanning electron microscopy from normal arteries vasoconstricted in vitro: both groups demonstrated a mean 57% reduction in vessel caliber and a 5-fold increase in vessel wall thickness compared to normal, nonvasoconstricted left MCAs. On transmission electron microscopy, however, arteries in SAH-induced VSP showed degenerative changes in the tunica intima and media. These changes were still evident at 14 days. despite considerable resolution of VSP. These findings, as well as those from other pathological studies of animal and human cerebral arteries in VSP, suggest that the arterial narrowing and vessel wall thickening seen within several weeks of SAH is due primarily to medial contraction, but unlike simple vasoconstruction, is associated with degenerative ultrastructural changes in the endothelium and vascular smooth muscle cells which may denote a temporarily irreversible state.

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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