Bioelectrochemical Modeling of Toluidine Blue Diffusion in a Hydrogel in the Presence of Peroxidase and Trypsin

Biophysics - The electrochemical behavior of a phenothiazine dye, toluidine blue, in a gelatin hydrogel in the presence of trypsin, peroxidase, and their combination was studied by cyclic...     

西伯利亚李斯特文卡遗址的大缺齿鼹化石

李斯特文卡（Лиственка）遗址位于俄罗斯西伯利亚叶尼塞河上游右岸的2级阶地,地理坐标为55°35′22″N,85°46′24″E。该遗址出土了丰富的细石器和骨器等文化遗存,是西伯利亚地区旧石器时代晚期重要文化遗址。遗址第7层距今时代约13.59-15.00 kaBP,从该层出土的哺乳动物化石中鉴定和研究了包括有3个个体的大缺齿鼹（Mogera robusta）化石材料。该批材料的发现,表明遗址古环境并不是以前人们认为的是处于冰缘森林-苔原和干草原-苔原环境,而应该是属于大陆性季风气候区,降水量比较充足且分布有泰加林和阔叶林组成的混交林地,具有软体动物、小哺乳动物、大哺乳动物等属种多样的良好生态环境。李斯特文卡遗址大缺齿鼹标本的研究,反映古人类在西伯利亚地区严寒而漫长的冬天里可能把捕捉大缺齿鼹作为重要的食物补充,为我们深入分析亚洲古人类文化交流、古人类体质进化及适应寒冷环境的生活方式等具有重要意义,对我们研究鼹科动物起源与演化等提供了重要研究素材。     

Physiological,biochemical, and fluorescence parameters of senescing sugar beet leaves in the vegetative phase of growth

The phase of vegetative growth of sugar beet (Beta vulgaris L., single-sprout form) was conditionally subdivided into four periods according to leaf number and size (including already withered leaves): (A) 8 ± 1 weeks after seedling emergence (wase) (5–7 leaves); (B) 11 ± 1 wase (10–12 leaves); (C) 14 wase (13–15 leaves); (D) 15 wase (15–18 leaves). It took each next leaf about 1 week to come into view. In the course of leaf senescence, palisade parenchyma became less ordered; cells, vacuoles, and intercellular spaces expanded; leaf area and thickness increased. Chloroplasts became swollen, starch grains (and later osmiophilic globules) accumulated and degraded. In every growth period, the highest levels of soluble carbohydrates (sCH), chlorophyll (Chl (a + b)), soluble protein, and the highest activities of rubisco and soluble carboanhydrase usually preceded the full leaf expansion. In unfolded leaves at the growth period B, the maximum values of biochemical characteristics were as a rule higher than at the growth periods A and C and especially D. The only exception was Chl (a + b) with its peak level somewhat increased with plant age. Occurrence of peak values of individual characteristics depended on plant growth period. These characteristics started diminishing asynchronously, with a minimum in old operational leaves. Only the sCH content in the leaves at the periods C and D was stable. Changes in quantum yield at PSII and nonphotochemical fluorescence quenching reflected the age-associated differences in biochemical characteristics. The results are discussed in the light of the idea that leaf senescence is a normal stage of development directly related to the changes in source-sink relations. Biochemically, this stage comprises the degradation of temporarily stored products and partial utilization of the breakdown products for maintenance of the growth of newly formed leaves and root.     

Spine skeleton morphogenesis during regeneration in clypeasteroid and camarodont sea urchins

The process of skeleton morphogenesis is described for broken and totally removed spines in clypeasteroid (hollow spine) and camarodont (solid spine) sea urchins. Spine regeneration after total spine removal is completed in 40–45 days in clypeasteroids and in 60–70 days in camarodont sea urchins. Along with common stages of formation of longitudinal ribs in both hollow and solid spines, fundamental differences were found between the initial stages of reparative growth of the spine shaft. The spine shaft is formed from a single median process in clypeasteroids and from many simultaneously growing processes in camarodont sea urchins. Reparative morphogenesis of totally removed and partly broken spines in clypeasteroid sea urchins and totally removed spines in camarodont sea urchins leads to the formation of a skeletal structure identical to the intact spine. However, during the regeneration of broken camarodont spines, lateral growth is markedly retarded. As a result, the regenerated part of the spine shaft has a smaller diameter when the initial spine length is achieved. A hypothesis is proposed on a paedomorphic origin of spines in the clypeasteroid sea urchins on the basis of the juvenile stage of definitive spines in the camarodont sea urchins.     

Genetic variability of isolates of pandemic influenza A virus H1N1 isolated in Russia in 2009

Complete nucleotide sequence of the genome segments encoding the surface glycoproteins, hemagglutinin, and neuraminidase of influenza A virus H1N1 derived from the patients with influenza in the context of pandemic (H1N1) 2009 was determined out of 14 isolates of pandemic influenza. The philogenetic analysis of these sequences demonstrated their genetic similarity to the corresponding genes of the pandemic influenza virus A (H1N1) 2009 isolates obtained in other countries; each gene homology was greater than 99%. Neuraminidase mutations causing virus resistance to oseltamivir and other neuraminidase inhibitors, known from the literature, were not detected. The hemagglutinin gene mutation D222G was found in 4 isolates from autopsy material. In the hemagglutinin of pandemic A/Salekhard/01/2009(H1N1) isolate a mutation G155E leading to the increase in viral replication in developing chick embryos was detected. The nature and frequency of nucleotides substitutions within HA and NA genes were determined in the current research.     

Genotyping of rubella virus circulating in Western Siberia of Russia during 2004-2006 epidemic period

Twenty one strains of rubella virus were isolated in the Western Siberia during 2004-2006 epidemic period. Genotyping of isolated strains was performed by partial sequencing of glycoprotein E1 gene. Phylogenetic analysis showed that 20 out of 21 isolated in the Western Siberia strains of rubella virus belonged to genotype 1g, and 1 strain (isolated in Altai region in 2006)--to genotype 1E.     

Cytotoxic derivatives of (22R,23R)-dihydroxystigmastane

(22R,23R)-22,23-dihydroxystigmast-4-en-3-one, (22R,23R)-22,23-dihydroxystigmast-4-en-3,6-dione, (22R,23R)-3β,5α,6β,22,23-pentahydroxystigmastane, (22R,23R)-5α,6α-oxido-3β,22,23-trihydroxystigmastane, (22R,23R)-5β,6β-oxido-3β,22,23-trihydroxystigmastane, and (22R,23R)-3β,6β,22,23-tetrahydroxystigmast-4-ene were synthesized. Their cytotoxicities were comparatively studied using the MCF-7 line of carcinoma cells of human mammary gland and cells of human hepatoma of the Hep G2 line.