Morphological Investigation of Solute Particles Trapped from an Air-Acetylene Flame

1986 ◽  
Vol 40 (7) ◽  
pp. 939-944 ◽  
Author(s):  
A. G. Childers ◽  
G. M. Hieftje
Keyword(s):  
Electron Microscopy ◽  
Structural Changes ◽  
Hollow Spheres ◽  
Structure Characteristic ◽  
Morphological Investigation ◽  
Droplet Generator ◽  
Trapped Particles ◽  
Morphological Studies ◽  
Uniform Droplet ◽  
Scanning Electron

A uniform-droplet generator has been employed to produce individual desolvated KCl particles in a laminar air-acetylene flame. The resulting particles were collected on various surfaces and at different points in their vaporization history. Morphological studies were then conducted on the trapped particles in order to better characterize the structural changes which occur during desolvation and vaporization. Particles collected early in their vaporization exhibited strong crystalline structure characteristic of KCl, whereas particles gathered later in their volatilization history showed evidence of fusion and, in some cases, the formation of hollow spheres. In addition to the morphological studies, the various collection surfaces and the collection technique itself were assessed. Direct collection on scanning-electron microscopy specimen stubs was judged to be best.

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.

scholarly journals Redox Mechanism of Azathioprine and Its Interaction with DNA

2021 ◽  
Vol 22 (13) ◽  
pp. 6805
Author(s):  
Mihaela-Cristina Bunea ◽  
Victor-Constantin Diculescu ◽  
Monica Enculescu ◽  
Horia Iovu ◽  
Teodor Adrian Enache
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Scanning Electron Microscopy ◽  
Structural Changes ◽  
Differential Pulse ◽  
Immunosuppressive Drug ◽  
Redox Mechanism ◽  
Before And After ◽  
Dna Film ◽  
Scanning Electron

The electrochemical behavior and the interaction of the immunosuppressive drug azathioprine (AZA) with deoxyribonucleic acid (DNA) were investigated using voltammetric techniques, mass spectrometry (MS), and scanning electron microscopy (SEM). The redox mechanism of AZA on glassy carbon (GC) was investigated using cyclic and differential pulse (DP) voltammetry. It was proven that the electroactive center of AZA is the nitro group and its reduction mechanism is a diffusion-controlled process, which occurs in consecutive steps with formation of electroactive products and involves the transfer of electrons and protons. A redox mechanism was proposed and the interaction of AZA with DNA was also investigated. Morphological characterization of the DNA film on the electrode surface before and after interaction with AZA was performed using scanning electron microscopy. An electrochemical DNA biosensor was employed to study the interactions between AZA and DNA with different concentrations, incubation times, and applied potential values. It was shown that the reduction of AZA molecules bound to the DNA layer induces structural changes of the DNA double strands and oxidative damage, which were recognized through the occurrence of the 8-oxo-deoxyguanosine oxidation peak. Mass spectrometry investigation of the DNA film before and after interaction with AZA also demonstrated the formation of AZA adducts with purine bases.

scholarly journals Catatropis pakistanensis n. sp. (Trematoda: Notocotylidae) from Northern shovelers, Anas clypeata (Anatidae: Aves) from Pakistan with some remarks on the history of Catatropis species

2012 ◽  
Vol 49 (1) ◽  
pp. 43-48 ◽  
Author(s):  
R. Schuster ◽  
G. Wibbelt
Keyword(s):  
Electron Microscopy ◽  
Histological Evaluation ◽  
Thin Sections ◽  
Genital Opening ◽  
Morphological Studies ◽  
Anas Clypeata ◽  
History Of ◽  
Free Ranging ◽  
A New Species ◽  
Scanning Electron

AbstractFive out of 15 free-ranging Northern shovelers (Anas clypeata Linneus) caught in Pakistan were infected with notocotylid trematodes. Out of the 31 flukes, 10 specimens were used morphological studies, 4 others were also examined by scanning electron microscopy and one remaining trematode was cut in serial semi-thin sections for histological evaluation in order to describe a new species. Like all species of this genus, Catatropis pakistanensis n. sp has a median ridge starting posterior to the basis of the cirrus sac and extends posterior to the ovary. Bilateral to this ridge there are two rows of 9–10 ventral papillae each. Metraterm and cirrus sac are equally in length. In contrast to most other Catatropis spp. the genital opening in C. pakistanensis is situated between the oral sucker and bifurcation of the caeca.

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.

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.

Preparation of PS@SiO2, PS@TiO2，PS@TiO2/SiO2 Core-Shell Composites by a Spray Drying Process and Their Hollow Spheres after Removing PS Cores by Calcinations

2011 ◽  
Vol 194-196 ◽  
pp. 389-392
Author(s):  
Ling Li ◽  
Hong Liang Li ◽  
Ying Chun Zhu ◽  
Ai Ping Fu ◽  
Yong Wan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Spray Drying ◽  
Hollow Spheres ◽  
Nitrogen Adsorption ◽  
Core Shell ◽  
Drying Process ◽  
The Core ◽  
Adsorption Desorption ◽  
Drying Chamber ◽  
Scanning Electron

Polystyrene (PS) spheres encapsulated core-shell composites of SiO2or TiO2nanoparticles were prepared by the spray drying technique and hollow spheres of SiO2or TiO2nanoparticles were then derived by removing the PS cores with calcinations. The PS spheres were dispersed into the SiO2or TiO2colloids, forming a suspension and then the suspensions were sprayed to form micrometer-sized droplets, as the droplets rush through the drying chamber, the PS spheres were encapsulated into the core of SiO2or TiO2particles due to the high temperatures and the instant evaporation, obtaining PS@SiO2, PS@TiO2or PS@SiO2/TiO2core-shell composites. After removing the PS core by calcination at 550°C, SiO2or TiO2hollow spheres were then derived. The influence of drying temperature, the concentration of the SiO2or TiO2particles and the ratio of PS sphere to the particles on the structures and specific surface area of the hollow spheres were studied with scanning electron microscopy (SEM) and nitrogen adsorption-desorption measurements.

scholarly journals Effects of Droplet-Vitrification Cryopreservation Based on Physiological and Antioxidant Enzyme Activities ofBrassidiumShooting Star Orchid

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Safrina Rahmah ◽  
Safiah Ahmad Mubbarakh ◽  
Khor Soo Ping ◽  
Sreeramanan Subramaniam
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Liquid Nitrogen ◽  
Enzyme Activities ◽  
Structural Changes ◽  
Total Soluble Protein ◽  
Antioxidant Enzyme Activities ◽  
Droplet Vitrification ◽  
The Impact ◽  
Scanning Electron

Protocorm-like bodies (PLBs) ofBrassidiumShooting Star orchid were successfully cryopreserved using droplet-vitrification method. Vitrification based cryopreservation protocol is comprised of preculture, osmoprotection, cryoprotection, cooling, rewarming, and growth recovery and each and every step contributes to the achievement of successful cryopreservation. In order to reveal the lethal and nonlethal damage produced by cryopreservation, histological observation, scanning electron microscopy (SEM), and biochemical analysis were carried out in both cryopreserved and noncryopreserved PLBs ofBrassidiumShooting Star orchid comparing with the control PLBs stock culture. Histological and scanning electron microscopy analyses displayed structural changes in cryopreserved PLBs due to the impact of cryoinjury during exposure to liquid nitrogen. Total soluble protein significantly increased throughout the dehydration process and the highest value was achieved when PLBs were stored in liquid nitrogen. Ascorbate peroxidase (APX) and catalase (CAT) showed the highest enzyme activities in both dehydration and cryostorage treatments indicating that stress level of PLBs was high during these stages.

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.

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