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991.
992.
The paper submits the results of studies on the kinetics of spermatogenous epithelium cell number after exposure to fast neutrons (60-300 cGy) and gamma-radiation (200-600 cGy). It was shown that a relative decrease in the quantity of spermatocytes is determined by an exponential dose-response curve with D0 of 35 and 120 cGy for neutrons and gamma-radiation respectively. For spermatides and spermatozoa a single D0 value of 20 and 55 cGy was obtained for neutrons and gamma-radiation respectively. As the radiation dose increases the recovery process in the epithelium is substantially decelerated. The equation T1/2 = T1/2(0)e0.0009D well describes the dependence of the half-recovery period T1/2 upon the equivalent dose. 相似文献
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994.
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996.
The seminal receptacle or spermatheca of Portunus sanguinolentus consists of two parts--an anterior glandular and a posterior chitinous part. The chitinous part continues as the oviduct, which opens on the sternite of the sixth thoracic segment. Significant morphological and histological differences were observed between the spermatheca, as well as the oviduct, of mated and unmated crabs. In mated crabs the spermatheca is much more bulging, owing to receipt of a copious supply of seminal products, and its cells are hyperactive. Further stages of ovarian development were observed as indicators of sequential changes in the spermatheca. The secretory cells gradually disintegrate by way of holocrine secretion; this results in cellular stratification and the formation of distinct furrows in the chitinous posterior part. 相似文献
997.
998.
K M Raines 《The Journal of parasitology》1989,75(4):601-605
Prairie voles, Microtus ochrogaster, were infected with Eimeria ochrogasteri and exposed to 2 environmental temperatures, 5 and 22 C. Dry weights of the small and large intestines increased by 33% and 19%, respectively, in infected animals. Infected animals also exhibited a 14% decrease in cecal length compared to uninfected animals. The interaction between temperature and infection affected the length of the small intestine. Infected animals maintained at 5 C had longer small intestines than both infected animals housed at 22 C, and uninfected animals at 22 or 5 C. Furthermore, the dry weight of the small intestine was affected by a 3-way interaction (infection, temperature, and sex). Temperature affected stomach and liver dry weights, as well as lengths of the small intestine and cecum. Stomach and liver dry weights, as well as small intestine lengths, were greater in those animals held at 5 C, whereas cecum lengths decreased. Prepatency, patency, and total oocyst production were not affected by temperature; however, infected animals held at 5 C exhibited diarrhea during the patent period. 相似文献
999.
The cytotoxic and radiosensitizing effects of hyperthermia was shown on Ehrlich ascites tumor cells heated in vitro. The effect of hyperthermia resulted in the formation of local lesions in membranes of dying cells. 相似文献
1000.