scholarly journals Scanning Electron Microscopy and Kinetic Studies of Ketene-Acetylated Wood/Cellulose High-Density Polyethylene Blends

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Yakubu Azeh ◽  
Gabriel Ademola Olatunji ◽  
Paul Andrew Mamza
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Kinetic Studies ◽  
Wood Cellulose ◽  
Polyethylene Matrix ◽  
Polyethylene Blends ◽  
Morphological Studies ◽  
Alkali Solutions ◽  
Absorption Studies ◽  
Scanning Electron

Acetylated cellulose and wood cellulose as well as untreated cellulose polyethylene blends were subjected to kinetic studies using water, 0.5 M NaOH, and 0.5 M HCl solutions in order to investigate their absorbent properties at 0.5/1.0 cellulose/wood cellulose/polyethylene matrix. The results of the absorption studies showed that the untreated cellulose and wood cellulose blends absorbed water and the acid and alkali solutions higher than the treated samples, which showed a reduction in acid, alkali, and water uptake. In this work, the effects of acetylation on the morphological studies of the polyethylene blends were obvious. The presence of acetyl groups improved the interfacial bonding between the polymer matrix and cellulose as well as the wood cellulose fibers, as evidenced by scanning electron microscopy (SEM).

scholarly journals ELECTRON MICROSCOPIC STUDIES OF SOME ANTICANCER PLANTS POLLEN GRAINS

2021 ◽  
Vol 9 (10) ◽  
pp. 1386-1393
Author(s):  
Jayshree Sandesh Thaware ◽  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Pollen Morphology ◽  
Pollen Grains ◽  
Morphological Characters ◽  
Electron Microscopic ◽  
Plant Parts ◽  
Morphological Studies ◽  
Datura Metel ◽  
Scanning Electron

Pollen is appropriately referred by some as Golden dust extremely valuable on account of their tremendous applications in science, industries and public health. No other plant part even though extremely tiny in size is packed with so much information and power. Similar to other plant parts, pollen characters are so varied that the classification system of plants can be built up entirely on the basis of pollen morphology.Palynology is the distinct branch of biology that deals with the dispersed microscopic tiny living and fossil entities including pollen grains, spores, algal and fungal fragments and others. An important aspect of Palynology is the Pollen morphology. The importance of Palynology in taxonomic and phylogenetic consideration of plants is well known. The changes occurring through hybridization and years of cultivation are reflected in pollen morphology. The scope and interest in the study of pollen morphology have widened with the advent of Scanning Electron Microscopy (SEM) and with regards to unipalynous taxa particularly the understanding of finer morphology is of fundamental importance. SEM gives a correct understanding of exine surface as the electron photographs of the surface replica of the exine provides the exact picture of the ornamentation pattern. The variation in the pollen morphological characters helps in the classification of plant taxa and their assessment of their phylogenetic relationship. In the present investigation, the pollen morphological studies were carried out of some ethnomedicinal plants like Catharanthus roseus, Allamanda cathartica, Datura metel, Brassica juncea, Raphanus sativus and Cleome viscosa pollen grains by Scanning electron microscopy. All that they possess anticancer characteristics in common.

Light and Scanning Electron Microscopy of Human Spinal Ligaments

1985 ◽  
Vol 55 ◽  
Author(s):  
L.-H. Yahia ◽  
G. Drouin ◽  
C.-H. Rivard
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Connective Tissue ◽  
Idiopathic Scoliosis ◽  
Blood Vessels ◽  
Structural Changes ◽  
Loose Connective Tissue ◽  
Morphological Studies ◽  
Spinal Ligaments ◽  
Scanning Electron

ABSTRACTSpinal ligaments were obtained from normal and scoliotic individuals. Detailed morphological studies were carried out on the yellow, interspinous and supraspinous ligaments by light and scanning electron microscopy. Normal yellow ligaments are mostly constituted of dense elastin fibers with only a few collagen fibers and sparse blood vessels, while in normal interspinous and supraspinous ligaments, the presence of collagen is highly dominant. In the latter structures, the collagen fascicles are characterized by a regular waviness morphology. The fibrils constituting the fascicles appear either parallel or helical with respect to the fascicle axis. Structural changes are observed in the spinal ligaments of patients with congenital as well as idiopathic scoliosis. For yellow ligaments, only slight differences are found between normal and scoliotic specimens. However, alterations in collagen waviness and architecture are observed mainly in the supraspinous ligaments and to a lesser extent in the interspinous ligaments. In addition, increases in the cellularity, loose connective tissue and vessels are found in both forgoing ligaments. These results indicate that the more pronounced scoliosis-related changes occur in ligaments having the farthest distance from the axis of flexion-rotation.

Pollen morphology of Ginkgo biloba and Cycas revoluta

1986 ◽  
Vol 64 (12) ◽  
pp. 3075-3078 ◽  
Author(s):  
N. Sahashi ◽  
J. Ueno
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Ginkgo Biloba ◽  
Pollen Morphology ◽  
Pollen Grains ◽  
Spherical Form ◽  
Thin Sections ◽  
Morphological Studies ◽  
Cycas Revoluta ◽  
Scanning Electron

Morphological studies on pollen grains of Ginkgo biloba L. and Cycas revoluta Thunb. were carried out by scanning electron microscopy. The pollen grains of both species are generally oblong with 1-sulcate apertures which are shrunken as a result of dryness. However, the swollen grains show an almost spherical form with a large and rounded germinal aperture. This aperture may not correspond to any aperture type so far known, although the term "anaporate" can be fitted to the swollen pollen grains. Auricular projections, which may be derived from protrusions of the ectosexine, can be seen sometimes on the surface of the pollen grains. These projections remind us of degraded versions of the bladders that may have been present on the pollen grains of the fossil ancestor. The inner side of the exine, which can be seen in thin sections obtained with the freezing microtome, is ornamented with reticulumlike sculptures. These endosculptures may be the first reported among gymnosperm pollen grains.

Chemical and morphological studies of the effects of ageing on monoterpene composition in Mentha ×piperita leaves

1991 ◽  
Vol 69 (10) ◽  
pp. 2271-2278 ◽  
Author(s):  
N. Brun ◽  
M. Colson ◽  
A. Perrin ◽  
B. Voirin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cyclic Compound ◽  
Shoot Meristem ◽  
Mentha Piperita ◽  
Gas Chromatograph ◽  
Distal Extremity ◽  
Morphological Studies ◽  
Monoterpene Composition ◽  
Scanning Electron

The effects of ageing on monoterpene composition in Mentha ×piperita have been studied by analyses of microsamples obtained by coupling a desorption–concentration–introduction technique with a gas chromatograph. The appearance and the development of the two types of glands of shoot meristem studied by scanning electron microscopy show that the capitate glands appear before the peltate glands. The chromatographic analyses of meristem and different primordial leaf pairs show that the monoterpenes are only detected if the leaf bears peltate glands and that the first cyclic compound accumulated is limonene. The biochemical variations of the reduction of menthone to menthol in the midstem leaves and of acetylation of menthol in the basal leaves start at the distal extremity of the leaf and progressively move towards the base. The maturation of the plant followed by the shift of the level of leaf in which menthone and menthol are present with the same percentage as a function of time is a linear phenomenon. Key words: peppermint, trichomes, monoterpenes, biochemical variations, ageing.

Molecular and morphological studies identify a new genus within the Heterolepismatinae (Zygentoma: Lepismatidae)

Zootaxa ◽  
2021 ◽  
Vol 5030 (1) ◽  
pp. 1-118
Author(s):  
GRAEME B. SMITH ◽  
ANDREW MITCHELL ◽  
RAFAEL MOLERO-BALTANÁS
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Anterior Margin ◽  
New Genus ◽  
Sequence Data ◽  
Morphological Characters ◽  
Type Series ◽  
Morphological Studies ◽  
Molecular Studies ◽  
Scanning Electron

Molecular studies using COI and 28S sequence data strongly identify a clade within the Heterolepismatinae distinct from the majority of species so far sequenced. The independence of the clade is supported by several morphological characters including a glabrous anterior margin to the frons, large trapezoidal thoracic sternites, tarsal trichobothria, long, conical parameres which in some species consist of two segments, and the presence of triangular or rounded subrectangular scales on the femora, tibia and clypeus. This clade is described as a new genus Visma n. gen. containing ten new species V. advenum n. sp., V. bingara n. sp., V. brayi n. sp., V. bundjalung n. sp., V. brigalowsum n. sp., V. capricornia n. sp., V. pallidum n. sp., V. powellheueri n. sp., V. tenebrosum n. sp. and V. xanthorrhoea n. sp.. Heterolepisma stilivarians Silvestri, 1908 is redescribed from the holotype and transferred to the new genus. The remaining H. stilivarians type series is found to be different to the holotype and removed from the type series. It is considered possible that H. annectens Silvestri, 1924 may also belong to this genus. Scanning electron microscopy of scale shape and rib-spacing is shown to be a useful tool to separate at least some species of the genus and considered to have greater potential if well preserved material is available.  

Morphological studies of human arteriovenous malformations

1985 ◽  
Vol 63 (3) ◽  
pp. 421-425 ◽  
Author(s):  
Peter M. Klara ◽  
Eugene D. George ◽  
Dennis E. McDonnell ◽  
Paul H. Pevsner
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Arteriovenous Malformations ◽  
Lattice Structure ◽  
Balloon Catheter ◽  
Surgical Removal ◽  
Content Type ◽  
Morphological Studies ◽  
Micro Channels ◽  
Scanning Electron

✓ Ten patients with symptomatic arteriovenous malformations (AVM's) underwent embolization with isobutyl 2-cyanoacrylate (Bucrylate) delivered via a mini-balloon catheter according to the protocol of George and Pevsner. These patients underwent surgical removal of their embolized AVM, and surgical specimens were evaluated by light and scanning electron microscopy. Ten other patients with AVM's underwent surgical resection without prior embolization, and these surgical specimens were evaluated in a similar manner. Results from this study indicate that Bucrylate incites an inflammatory response characterized by foreign-body giant cells. This reaction was present as early as 3 weeks after embolization and persisted in specimens resected almost 1 year after the last embolization. No such reaction was observed in unembolized AVM's. Both light and scanning electron microscopy demonstrated a lattice structure of the Bucrylate embolus within the AVM vessels. These studies also demonstrated micro-channels within the Bucrylate embolus and the presence of what appears to be normal red blood cells within the latticework of the embolus. Vascular endothelium not in direct contact with the Bucrylate embolus retains a normal morphology as revealed by scanning electron microscopy.

scholarly journals High-Fat Diet Impairs Mouse Median Eminence: A Study by Transmission and Scanning Electron Microscopy Coupled with Raman Spectroscopy

2021 ◽  
Vol 22 (15) ◽  
pp. 8049
Author(s):  
Ilenia Severi ◽  
Marco Fosca ◽  
Georgia Colleluori ◽  
Federico Marini ◽  
Luca Imperatori ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Raman Spectroscopy ◽  
Median Eminence ◽  
High Fat Diet ◽  
Dietary Lipids ◽  
High Fat ◽  
Initial Event ◽  
Morphological Studies ◽  
Scanning Electron

Hypothalamic dysfunction is an initial event following diet-induced obesity, primarily involving areas regulating energy balance such as arcuate nucleus (Arc) and median eminence (ME). To gain insights into the early hypothalamic diet-induced alterations, adult CD1 mice fed a high-fat diet (HFD) for 6 weeks were studied and compared with normo-fed controls. Transmission and scanning electron microscopy and histological staining were employed for morphological studies of the ME, while Raman spectroscopy was applied for the biochemical analysis of the Arc-ME complex. In HFD mice, ME β2-tanycytes, glial cells dedicated to blood-liquor crosstalk, exhibited remarkable ultrastructural anomalies, including altered alignment, reduced junctions, degenerating organelles, and higher content of lipid droplets, lysosomes, and autophagosomes. Degenerating tanycytes also displayed an electron transparent cytoplasm filled with numerous vesicles, and they were surrounded by dilated extracellular spaces extending up to the subependymal layer. Consistently, Raman spectroscopy analysis of the Arc-ME complex revealed higher glycogen, collagen, and lipid bands in HFD mice compared with controls, and there was also a higher band corresponding to the cyanide group in the former compared to the last. Collectively, these data show that ME β2-tanycytes exhibit early structural and chemical alterations due to HFD and reveal for the first-time hypothalamic cyanide presence following high dietary lipids consumption, which is a novel aspect with potential implications in the field of obesity.

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