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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A cytochemical and electron microscopic study of nucleoli in amphibian oocytes

Brown, Charles Augustus, January 1956 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1956. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 72-78).
2

A histochemical investigation into the regional distribution of monoamine oxidase in the brain-stem of rabbit and cat with atlas of related concentrations

Halsey, Nancy M. January 1962 (has links)
In the last decade, considerable interest has been focused on the role of biogenic amines and their function in the central nervous system. Certain of these, norepinephrine and serotonin, have been suggested as neurotransmitters, and evidence has accumulated that rise in the levels of these amines results in behavioural change. At the same time, it was found that the enzyme, monoamine oxidase (MAO), utilized these compounds as substrates, and that inhibition of MAO resulted in elevated levels of the catecholamines and serotonin. This knowledge has led to considerable investigation of the areas of brain that might be affected by this inhibition, but beyond the preliminary report of Shimizu et al. (1959) little had been done to determine the histochemical localization of MAO by methods of proven specificity. A study of the brain-stem has therefore been attempted, to determine the major sites of MAO activity. Rabbit and cat brain-stem have been used, and the histochemical method of Glenner, Burtner and Brown (1959) using nitro-blue tetrazolium. Fresh frozen tissue was cut on the cryostat and sections incubated with this solution, a positive result producing a purple-blue formazan precipitate. For identification and correlation of brain-stem nuclei, adjacent sections were cut and stained with toluidine blue. Controls were run in vitro and in vivo with known MAO inhibitors, as well as by incubation without substrate, application of heat and alteration of pH. Finally, an atlas has been prepared identifying the sites of MAO activity and suggesting a functional relationship based on these studies. Results indicate that within the brain, the brain-stem itself contains the highest proportion of MAO, which is concentrated within the following regions - choroid plexus, pineal gland, hypothalamus, pituitary, interpeduncular nucleus, habenulo-pedencular tract, dorsal tegmental nucleus, locus coeruleus, area postrema and cranial nerve nuclei, especially the distal portion of the trigeminal nucleus and the dorsal vagal nuclei. The thalamus, inferior colliculi and major fibre tracts were all conspicuously low in MAO. With the exception of the cells of the mesencephalic nucleus of nerve V, activity did not occur within the body of the neuron, but was present in the neuropil of the neocortex and all other positive areas of brain-stem. Certain peculiarities of distribution were noted for the glandular areas of the pineal, pituitary and choroid plexus. In the anterior pituitary and choroid plexus, MAO was found in intracellular granules, but within the pineal and posterior pituitary the activity appeared to lie in a matrix between cells. / Medicine, Faculty of / Graduate
3

The histochemical identification of lipoids in the animal kingdom

Cain, Arthur James January 1948 (has links)
No description available.
4

Seasonal changes in the ultrastructure and histochemistry of thenewt (Trituroides hongkongensis, Myer and Leviton) testes

曹志勳, Tso, Chi-fan, Elaine. January 1971 (has links)
published_or_final_version / Zoology / Master / Master of Science
5

Quantitative histochemical and morphometric studies on autonomic neurones

Baker, D. M. January 1987 (has links)
No description available.
6

Aspects of the structure and function of the human salivary glands

Adi, Mohamad M. January 1992 (has links)
No description available.
7

A study of the use of hydrophilic resins in diagnostic histopathology

Hand, N. M. January 1988 (has links)
No description available.
8

The rootlet system of rhizocephalan barnacles

Russell, Jonathan David January 1998 (has links)
No description available.
9

The morphology and histochemistry of the life history of Eimeria Libeana Pinto, 1928

Srivastava, Hirendra Kumar January 1964 (has links)
Thesis (Ph.D.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / The study was undertaken with the purpose of redescribing the life history stages of E. labbeana and working out the histochemistry of different stages. Freshly discharged oocysts were of two sizes, large and small. Each oocyst possessed an outer transparent membrane, a thick intermediate membrane, and a thin inner membrane. The cytoplasm was in a state of flow and the nucleus appeared as a halo. Oocysts with incompletely formed walls and degenerate oocysts were also found to be shed along with mature oocysts. Biometrical studies indicated that the "ideal" size of the oocyst was 19.2u ± 0.27u x 17 . 5u ± 0.21u. There was no special difference in the size of the oocyst early and late in the patent period. Observation of sporogony at room temperature revealed that the first change in freshly discharged oocysts took place after 9 to 9 1/2 hours when protoplasm was withdrawn to a globular form. One to three polar bodies arose from any point. After 20 to 21 1/2 hours sporoblasts appeared abruptly. The first division was longitudinal and the second transverse. At about 33 hours sporoblasts changed to sporocysts. At about 59 hours the cytoplasm of sporocysts divided to form 5 refractile globules. The sporocyst had a double wall, the inner one reaching up to the base of the Stieda body. Two refractile globules (future sporozoites) were at either end. The average length and width of the sporocyst was 12.4u ± 0.34u X 6.4u ± 0.08u.[TRUNCATED] / 2031-01-01
10

Estudo morfofisiológico dos ovários e do corpo gorduroso do carrapato-estrela Amblyomma cajennense Fabricius (1787) (Acari : Ixodidae)

Denardi, Sandra Eloisi [UNESP] 15 August 2008 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-08-15Bitstream added on 2014-06-13T20:01:08Z : No. of bitstreams: 1 denardi_se_dr_rcla.pdf: 1067093 bytes, checksum: ab9cf962b002b3b79e7f62ce680eb8d9 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os ovários e o corpo gorduroso estão envolvidos na reprodução dos Arthropoda. A vitelogênese, que ocorre nos ovócitos dos Arthropoda em geral, incluindo os carrapatos, envolve a síntese endógena e a incorporação exógena de elementos que nutrirão o embrião. No presente estudo por meio da aplicação de técnicas de morfologia, morfometria, histoquímica, ultra-estrutura, citoquímica ultraestrutural e eletroforese analisou-se o ovário e o corpo gorduroso de fêmeas semiingurgitadas de carrapatos Amblyomma cajennense. O ovário é do tipo panoístico (sem a presença de células nutridoras) com desenvolvimento assincrônico dos ovócitos, os quais foram classificados em 5 estágios. Os ovócitos estão presos à parede do ovário por meio do pedicelo celular que participa também do fornecimento de substâncias do vitelo para o interior do ovócito. O vitelo dos ovócitos de A. cajennense é de natureza glicolipoprotéica, onde o lipídio é depositado primeiramente, seguido das proteínas e finalmente dos carboidratos. Os lipídios nestes ovócitos teriam origem nas mitocôndrias (produção endógena) e nas células do pedicelo. As proteínas do vitelo estão presentes já nos ovócitos em estágios iniciais de desenvolvimento, onde se observa grande quantidade de retículo endoplasmático granular, confirmando um processo de auto síntese protéica... / The ovaries and the fat body are involved in the reproduction of Arthropoda. The vitellogenesis, which occurs in oocytes of Arthropoda in general, including ticks, involves the endogenous synthesis and exogenous uptake of compounds that will nourish the embryo. In the present study, the ovaries and fat bodies of partially engorged female ticks Amblyomma cajennense were examined using methods of morphology, morphometry, histochemistry, ultrastructure, ultrastructural cytochemistry, and electrophoresis. The ovary is panoistic (devoid of nurse cells) and oocytes develop asynchronously, which were classified in 5 stages. Oocytes are attached to the ovary wall by pedicel cells that also provide yolk constituents to the oocyte. The yolk of oocytes of A. cajennense consists of glycolipoproteins, in which lipids are deposited first, followed by proteins, and finally carbohydrates. Lipids in these oocytes probably originate in mitochondria (endogenous production) and pedicel cells. Yolk proteins are already present in oocytes in early developmental stages, in which large quantities of granular endoplasmic reticulum are observed, confirming a process of protein autosynthesis. Another site of yolk protein production in A. cajennense is the pedicel cells, indicating that the fat body in this species contributes little or even does not contribute with proteins for oocytes. Small quantities of yolk carbohydrates are found in less developed oocytes, in which uptake occurs in late maturation stages, and its... (Complete abstract click electronic access below)

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