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31.
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A Neuro-Comparative Study between Single/Successive Thorium Dose Intoxication and Alginate Treatment
Mohamed M. Rezk 《Biological trace element research》2018,185(2):414-423
The adult male albino rats were grouped into five groups (control group and four variably treated groups with thorium (Th) in single or successive with or without alginate treatment). The IP administration of thorium nitrate (13.6 mg/kg b.wt.) induced a regional distribution and accumulation ordered as cerebellum > cerebral cortex > brain stem > hippocampus > hypothalamus > striatum. Also, it induces a significant increase in Na+, Ca2+, and Fe3+ ion content and malondialdehyde (MDA) level while K+ ions and glutathione (GSH) level were significantly decreased. On the other hand, the daily oral administration of 5% alginate showed a significant decreasing in the accumulation of thorium in the different brain areas and mitigated its hazardous effects. By the alginate treatment, Na+, Ca2+, Fe3+, and level of MDA were declined while K+ ions and GSH level showed a significant increase. The improvement of the investigated parameters was attributed to the specific chelating, regeneration, and antioxidant properties of the alginate. So, alginate administration could ameliorate the hazardous effects of thorium nitrate. 相似文献
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T. V. Khmara M. A. Riznichuk L. A. Strizhakovskaya 《Russian Journal of Developmental Biology》2018,49(2):101-107
Virtually no information on the chronology of prenatal development of the human urinary tract and the sex-related differences in the emergence of urinary tract topography during embryonic development is presently available. The aim of our work was to study sex-related differences in urethra development in human embryos and early fetuses. Forty-nine preparations of human embryos and early fetuses without external signs of anatomical abnormalities were studied in order to achieve the aim and fulfill the objectives of the study. Embryos and early fetuses were divided into six groups according to gestational age and parietococcygeal length. The complex of adequate methods of morphological research used in the study included preparation and microscopy of serial histological and anatomical sections of human embryos, including female and male urinary tracts, preparation of 3D-reconstruction models, and morphometry. The formation of prostatic urethra, a derivative of the urogenital sinus, was shown to occur at the beginning of the ninth week of embryogenesis, and the primordium of the internal sphincter of the urinary tract was formed at the end of the tenth week. Formation of the terminal part of spongy urethra took place during weeks 10–11 and involved funnel-like protrusion of the ectoderm from the top of the balanus towards the urethra lumen. The secondary ventral displacement of the urethral opening does not occur in female fetuses, and, therefore, only the prostatic urethra is a homolog of the female urinary tract. The pelvic part of the urogenital sinus was transformed into the prostatic urethra and the membranous urethra of the male at the end of the first stage of fetal development. Elongation of the genital tubercle (a penis primordium) and formation of the urethral ridge walls that involved the urogenital folds occurred at the same time. 相似文献
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S. I. Gritsinin P. A. Gushchin A. M. Davydov E. V. Ivanov I. A. Kossyi M. A. Misakyan 《Plasma Physics Reports》2009,35(11):933-940
A microwave coaxial plasmatron (microwave torch) is used as a plasmachemical converter of methane into hydrogen and hydrocarbons.
The measured energy cost of methane decomposition is close to its minimum theoretical value. Such a low energy cost is unsurpassed
for reactors operating at atmospheric pressure. A model of the plasmachemical converter is constructed. The results of calculations
in the frame-work of this model agree well with experimental data. 相似文献
37.
The diversity of cultured aerobic organisms collected from water samples and bottom sediment from two areas of natural oil
seepage on Lake Baikal has been researched. Representatives of Alpha-, Beta-, and Gammaproteobacteria have been found in samples
collected near the Bol’shaya Zelenovskaya River mouth, while near Cape Gorevoi Utes Betaproteobacteria were absent. Most cultures
are characterized by a sufficiently high homology level (96–100%) with nucleotide sequences from the international database. 相似文献
38.
Roberta L. Millstein 《Journal of the history of biology》2008,41(2):339-367
Biologists and philosophers have been extremely pessimistic about the possibility of demonstrating random drift in nature,
particularly when it comes to distinguishing random drift from natural selection. However, examination of a historical case
– Maxime Lamotte’s study of natural populations of the land snail, Cepaea nemoralis in the 1950s – shows that while some pessimism is warranted, it has been overstated. Indeed, by describing a unique signature
for drift and showing that this signature obtained in the populations under study, Lamotte was able to make a good case for
a significant role for␣drift. It may be difficult to disentangle the causes of drift and selection acting in a population,
but it is not (always) impossible. 相似文献
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