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111.
Paleontological Journal - The first record of fruit bodies of a microscopic fungus on the leaf of an unidentified dicotyledonous plant in amber is reported. The fungus is represented by numerous...  相似文献   
112.
113.
Fractional and component compositions of protein–lipid composites with increased nutritive value (compared to the protein preparations from which they were produced) were studied based on solubility and electrophoretic behavior. Differences in the fractional compositions of proteins and the amounts of hydrogen, ionic, and hydrophobic bonds were found. It was demonstrated that the water-, salt-, and alkali-soluble fractions of proteins changed during the manufacturing of the composites with soybean and wheat bran flour; the water- and alkali-soluble fractions, with protein concentrate from bran. Heterogeneity of the compositions and specific conformational features of composite proteins resulting from disulfide bonds were found. It was demonstrated that, during the manufacturing of composites, proteins of soybean flour aggregated (with the involvement of disulfide bonds), whereas protein products from wheat bran disaggregated. Breaks of interchain (wheat) or intrachain (concentrate) disulphide bonds accompanied the disaggregation. Overall the properties and specific structural features of the protein–lipid composites studied depended on the nature of the protein (soybean or wheat), type of initial preparations (flour or concentrate), and method of their production (emulsifying or drying).  相似文献   
114.
The results of analysis of specific characteristics of the heart rate variability (HRV) regulation in preschool children living under the Arctic high-latitude conditions are presented. The principal ageand gender-specific differences in the HRV regulation have been inferred from the intergroup evaluations of the HRV indicators in boys and girls. A functional developmental delay has been shown in 2.5-year-old girls compared with boys of the same age group. The applied orthostatic test has shown lower reserve capacities in children of the senior group compared with the junior group. It has been shown that the mechanisms of the regulation of cardiac rhythm in girls experience higher strain during orthostasis as compared with boys. The division of children into age groups with an age difference of one year has allowed the detection of the tendency towards basically different responses to functional loads during orthostasis. The mean HRV values characteristic of four- to six-year-old children living in the Arctic are presented. It has been shown that the children living at middle latitudes have a higher adaptive potential compared with the children living in high-latitude Arctic areas.  相似文献   
115.
The interaction between mouse angora-Y (Fgf5 go-Y) and hairless (hr) genes have been studied. Homozygous mutant gene Fgf5 go-Y increases length of all hair types, while homozygotes for the h gene lose hair completely starting on day 14 after birth. We obtained mice with genotypes +/+ hr/hr F2, +/Fgf5 go-Y hr/hr and Fgf5 go-Y/Fgf5 go-Y hr/hr. Both +/Fgf5 go-Y hr/hr and +/+ hr/hr mice began to loose hair from their heads on day 14. This further extended on the whole body. On day 21 the mice were completely deprived of hair. Therefore a single dose of gene Fgf5 go-Y does not modify alopecia in mice homozygous for hr. However in double homozygotes Fgf5 go-Y/Fgf5 go-Y hr/hr alopecia started 4 days later, namely on day 18. It usually finished 10–12 days after detection of first bald patches. On days 28–30 double homozygotes lose coat completely. Hair loss in double homozygous mice was 1.5-fold slower than in +/+ hr/hr mice. This resulted from a significant extension of anagen phase induced by a mutant homozygous gene Fgf5 go-Y in morphogenesis of the hair follicle. The hr gene was expressed at the transmission phase from anagen to catagen. Our data shows that the angora gene is a modifier of the hairless gene and this results in a strong repression of alopecia progression in double homozygous mice compared to +/+ hr/hr animals.  相似文献   
116.
Spontaneous symmetry breaking in reactive systems, known as a rare physical phenomenon and for the Soai autocatalytic irreversible reaction, might in principle also occur in other, more common asymmetric reactions when the chiral product is capable to promote its formation and an element of "nonlinearity" is involved in the reaction scheme. Such phenomena are long sought after in chemistry as a possible explanation for the biological homochirality of biomolecules. We have investigated homogeneous organic stereoselective Mannich and Aldol reactions, in which the product is capable to form H-bridged complexes with the prochiral educt, and found by applying NMR spectroscopy, HPLC analysis, and optical rotation measurements 0.3-50.8% of random product enantiomeric excess under essentially achiral reaction conditions. These findings imply a hitherto overlooked mechanism for spontaneous symmetry breaking and, hence, a novel approach to the problem of absolute asymmetric synthesis and could have also potential significance for the conundrum of homochirality.  相似文献   
117.
The systemic and regional hemodynamics during antiorthostatic hypokinesia were studied in male Wistar rats using the radioactive microsphere technique. The animals were hanged up by the tail with the head tilted down (30 degrees) and were able to exercise using only front limbs. Twenty four hours long exposure to antiorthostasis induced significant changes in systemic hemodynamics as well as in regional blood flow in skeletal muscles, spleen, liver and pancreas. Antiorthostasis induced blood flow changes in lungs, heart and brain were less pronounced.  相似文献   
118.
Hemodynamics of intra-abdominally transplanted rat heart was studied. Investigations were performed on 14 rats 7 to 260 days after transplantation. Significant changes revealed included increase in coronary vascular resistance and decrease in coronary blood flow and left ventricular contractility. These hemodynamic changes are ascribed to total denervation of the transplanted heart, absence of pump function and asynchronous contractions of transplanted and recipient hearts.  相似文献   
119.
The peripheral blood helper and suppressor T cell activity in rabbits was studied by the method of concanavalin A-induced mitogenesis. Blood lymphocytes were stimulated in vitro with different concentrations of concanavalin A (8 micrograms/ml and 60 micrograms/ml, respectively). The effect of stimulated lymphocytes on proliferative response of allogenic lymphocytes to phytohaemagglutinin was investigated. The liver injury was induced by three-fold subcutaneous injections of carbon tetrachloride (1 ml of 50% oil solution per 1 kg of body mass) each third day. Histological analysis of the liver and T cell activity examinations was performed 2, 9, 16, 30 days after carbon tetrachloride administration. It was shown that the stages of the more pronounced liver injury and the less pronounced regeneration of the liver were accompanied by the increase of helper T cell activity. The stages of the intensive liver regeneration and the less pronounced liver injury were accompanied by the increase of suppressor T cell activity.  相似文献   
120.
Three types of cells circulate in haemolymph of the crayfish Astacus astacus: agranular haemocytes (HCs I), small-granule haemocytes (HCs II) and large-granule haemocytes (HCs III). Their proliferation, differentiation and function remain poorly understood. By means of light and electron microscopic autoradiography using [3H]-thymidine, we have revealed that only HCs I are capable of DNA synthesis and mitosis whereas HCs II and HCs III are replicatively inactive. To determine whether the HCs I are proliferating progenitor cells for the granular HCs, we have analyzed autographs of HC population in 1, 2, 7 and 21 days after a single [3H]-thymidine administration. Contrary to the expectation, we have failed to find labeled HCs II and HCs III. These findings raise doubts on the capacity of the HCs I to differentiate into two other types of HCs. By autoradiography using 3H-uridine, it has been detected that intensity of the RNA synthesis was the greatest in HCs I and less by a factor of two and four in HCs II and HCs III, respectively. Additionally, by EM immunocytochemistry, ANP-like immunoreactivity was revealed in the large granules of the HCs III. We assume that availability of ANP in secretory granules extends the possible functions of the crayfish HCs and suggests their participation in regulation of water-salt balance and immune responses.  相似文献   
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