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1.
L B Hejfets L A Levina L V Salmin A A Antonova L S Segal M L Kuzminova K M Slavina A V Vasileva 《Journal of hygiene, epidemiology, microbiology, and immunology》1976,21(3):292-299
A total of 3 controlled field trials were carried out. One of them (1963) showed that aerosol chemical typhoid vaccine did not protect vaccinated subjects from the disease. Two other tests (1964 and 1965) assessing the effectivity of killed orally administered typhoid vaccine revealed a short term (up to 3 months) protective effect expressed by an effectivity coefficient of 45%, fiducial limits being 8-70%. In the assessment of oral paratyphoid B vaccine, the difference in morbidity in the experimental and control groups was statistically insignificant due to a small number of cases of disease. 相似文献
2.
Delyana
P Vasileva Jared
C Streich Leah
H Burdick Dawn
M Klingeman Hari B Chhetri Christa
M Brelsford J Christopher Ellis Dan M Close Daniel
A Jacobson Joshua
K Michener 《Nucleic acids research》2022,50(11):6211
In eukaryotes, fine-scale maps of meiotic recombination events have greatly advanced our understanding of the factors that affect genomic variation patterns and evolution of traits. However, in bacteria that lack natural systems for sexual reproduction, unbiased characterization of recombination landscapes has remained challenging due to variable rates of genetic exchange and influence of natural selection. Here, to overcome these limitations and to gain a genome-wide view on recombination, we crossed Bacillus strains with different genetic distances using protoplast fusion. The offspring displayed complex inheritance patterns with one of the parents consistently contributing the major part of the chromosome backbone and multiple unselected fragments originating from the second parent. Our results demonstrate that this bias was in part due to the action of restriction–modification systems, whereas genome features like GC content and local nucleotide identity did not affect distribution of recombination events around the chromosome. Furthermore, we found that recombination occurred uniformly across the genome without concentration into hotspots. Notably, our results show that species-level genetic distance did not affect genome-wide recombination. This study provides a new insight into the dynamics of recombination in bacteria and a platform for studying recombination patterns in diverse bacterial species. 相似文献
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This article considers the influence of the hydrological regime in the lower reaches of the Volga delta (based on the example of the Damchiksky site of the Astrakhan Reserve) during high water periods in the low-water year of 2012 and medium-water year of 2013 on the abundance of producers entering for spawning and the density of aggregations of juveniles of roach Rutilus caspicus, vulgaris rudd Scardinius erythrophthalmus, and river perch Perca fluviatilis. It is shown that the fish mass spawning in 2013 was more effective and occurred on floodplain spawning areas with the sequential succession of the investigated species, while the fish spawning was observed in eriks and was less effective in 2012. It was revealed that vulgaris rudd shows the highest adaptation to insufficient watering conditions. 相似文献
5.
Voitova A. A. Dmitrieva M. D. Dymova M. A. Vasileva N. S. Nushtaeva A. A. Richter V. A. Kuligina E. V. 《Russian Journal of Bioorganic Chemistry》2019,45(6):783-792
Russian Journal of Bioorganic Chemistry - Brain tumors are among the most intractable types of malignant neoplasms. Despite advances in the treatment of cancer, in particular, the development of... 相似文献
6.
Biliana Nikolova Severina Semkova Iana Tsoneva Georgi Antov Juliana Ivanova Ivanina Vasileva Proletina Kardaleva Ivanka Stoineva Nelly Christova Lilyana Nacheva Lyudmila Kabaivanova 《Engineering in Life Science》2019,19(12):978-985
Taking into account the rising trend of the incidence of cancers of various organs, effective therapies are urgently needed to control human malignancies. However, almost all chemotherapy drugs currently on the market cause serious side effects. Fortunately, several studies have shown that some non‐toxic biological macromolecules, including algal polysaccharides, possess anti‐cancer activities or can increase the efficacy of conventional chemotherapy drugs. Polysaccharides are characteristic secondary metabolites of many algae. The efficacy of polysaccharides on the normal and cancer cells is not well investigated, but our investigations proved a cell specific effect of a newly isolated extracellular polysaccharide from the red microalga Porphyridium sordidum. The investigated substance was composed of xylose:glucose and galactose:manose:rhamnose in a molar ratio of 1:0.52:0.44:0.31. Reversible electroporation has been exploited to increase the transport through the plasma membrane into the tested breast cancer tumor cells MCF‐7 and MDA‐MB231. Application of 75 µg/mL polysaccharide in combination with 200 V/cm electroporation induced 40% decrease in viability of MDA‐MB231 cells and changes in cell morphology while control cells (MCF10A) remained with normal morphology and kept vitality. 相似文献
7.
Phyllobothrium squali Yamaguti, 1952 is redescribed and illustrated on the basis of the holotype from Squalus acanthias from Japanese waters and specimens from the same host off the Bulgarian Black Sea coast (new geographical record). The species is characterised by: a scolex diameter of 2.9-4.3 mm, a glandular apical organ, foliose bothridia with folded and posteriorly bifid margins, accessory suckers of 286-367 micro m in diameter, 222-373 testes per proglottis, an oval cirrus-sac with a length of 354-655 micro m, the vagina opening anteriorly to the cirrus-sac, and the terminal part of vagina with a circular musculature. Specimens from Etmopterus spinax off Naples, Mediterranean Sea, recorded by Euzet (1959) as Crossobothrium squali, are redescribed and their identification not confirmed. P. squali is recognised as a specific parasite of S. acanthias; it is presently known only from Japanese waters, the Black Sea and the Irish Sea. Changes to the generic diagnosis of Phyllobothrium, as given by Ruhnke (1996a), are proposed in order to include the characters of P. squali. 相似文献
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Artificial endosperm of Cleopatra tangerine zygotic embryos: a model for somatic embryo encapsulation 总被引:1,自引:0,他引:1
Nieves Nadina Lorenzo Jose C. Blanco Maria de los A. González Justo Peralta Hipólito Hernández Martha Santos Ramón Concepción Oscar Borroto Carlos G. Borroto Eduviges Tapia Raúl Martinez Marcos E. Fundora Zaida González Alfredo 《Plant Cell, Tissue and Organ Culture》1998,54(2):77-83
Synthetic seed technology may be of value in breeding programs and allow the propagation of many elite genotype-derived plants
in a short time. In this work, a range of artificial endosperm treatments of Cleopatra tangerine zygotic embryos were evaluated
for suitability for encapsulation of somatic embryos. Different complexing ions in the form of alginate capsules, zeolite
as an ion exchanger and the relationship between capsule-nutrient gel on germination of zygotic embryos, were evaluated. Artificial
endosperm assays showed that abscisic acid (1 μM) and mannitol (0.25 M) delayed germination and conversion of zygotic embryos,
whereas amino acid supplements (proline, glutamic acid and arginine) accelerated the conversion process. An artificial endosperm
was used to encapsulate somatic and zygotic embryos. After encapsulation, zygotic embryos germinated after four days of culture
while somatic embryos germinated asynchronously after 20 days. Somatic embryo-derived plantlets showed greater vigour than
zygotic embryo-derived plantlets. Results showed that this artificial endosperm is adequate for Cleopatra tangerine somatic
embryo germination and conversion into plants.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
10.
Medvedeva A. V. Rebrova A. V. Zalomaeva E. S. Turaeva S. K. Nikitina E. A. Tokmacheva E. V. Vasileva S. A. Shchegolev B. F. Savvateeva-Popova E. V. 《Journal of Evolutionary Biochemistry and Physiology》2022,58(1):35-44
Journal of Evolutionary Biochemistry and Physiology - The paper continues the cycle of studies on the evolutionary link between the mechanisms of stress response formation and cognitive functions... 相似文献