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1.
The aim of this study was to investigate natural serpentine and non-serpentine populations of Teucrium polium aggr. and to document the differences in their morphological traits, as well as estimate which characters are most likely
contributing to differentiation of the populations. Nine populations distributed both on and off serpentine soils were investigated,
and 12 different morphological features of 270 individuals were studied by univariate and multivariate statistical analyses.
The results did not demonstrate clear delimitation of the serpentine from the non-serpentine populations. Using these ecotypes
as classification factors in the discriminant analysis, it can be stated that stem height, leaf length in the fifth leaf pair,
internode length between the fourth and the fifth leaf pairs, and corolla tube length are features with the greatest discriminant
ability. The character variation was generally higher for the vegetative features, while reproductive features failed to demonstrate
clear differences. The similarity groupings indicated by the cluster analysis were synchronous with groups distinguished by
both the discriminant and PCA analyses. Significant differences were observed between sets of vegetative characters in all
populations investigated.
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2.
Ilona Faustova Aleksei Kuznetsov Erkki Juronen Mart Loog Jaak Järv 《Central European Journal of Biology》2010,5(2):135-142
Among four pyruvate kinase isoenzymes, M1, M2, R and L, only M1 is considered as a nonallosteric enzyme. However, here we
show that the non-phosphorylated L-type pyruvate kinase (L-PK) is also a non-allosteric enzyme with respect to its substrate
phosphoenolpyruvate (PEP). The allosteric catalytic properties of L-PK are switched on through phosphorylation by cAMP-dependent
protein kinase. The non-phosphorylated enzyme was produced by expressing the rat L-PK in E. coli, as the bacterium does not have mammalian-type protein kinases. The resulting tetrameric protein was phosphorylated with
a stoichiometric ratio of one mole of phosphate per one L-PK monomer. Activity of the phosphorylated enzyme was allosterically
regulated by PEP with the Hill coefficient n=2.5. It was observed that allostery was engaged by phosphorylation of the first
subunit in the tetrameric enzyme, while further phosphorylation only modulated this effect. The discovered switching between
non-allosteric and allosteric forms of L-PK and the possibility of modulating the allostery by phosphorylation are important
for understanding of the interrelationship between allostery and the regulatory phosphorylation in general, and may have implication
for further analysis of glycolysis regulation in the liver.
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3.
E. L. Zdorovenko L. D. Varbanets O. S. Brovarskaya O. A. Valueva A. S. Shashkov Yu. A. Knirel’ 《Microbiology》2011,80(3):372-377
The structure and immunochemical properties of lipopolysaccharide from Budvicia aquatica 97U124, a representative of a novel species of Enterobacteriaceae, were studied. The O-polysaccharide (OPS) was isolated by mild acid hydrolysis and characterized by monosaccharide analysis
and NMR spectroscopy. It was shown that the OPS from B. aquatica 97U124 consisted of repeating units with the structure
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4.
S. F. Arkhipova I. V. Artem’yev E. A. Goryacheva V. Z. Pletnev 《Russian Journal of Bioorganic Chemistry》2008,34(5):544-549
Conformational analysis of two pairs of synthetic cyclodipeptides formed by interaction of both side chain functional groups ( , and ) and of the main and side chains ( , and ) was achieved by the method of molecular mechanics. The energetically optimal conformational states of the molecules under study were determined. It was shown that the conformational motility of cyclic system of the compounds under study depends on the relative arrangement of the amide groups and the number of atoms in the cycle. 相似文献
5.
Monika Łysakowska Andrzej Denys Monika Sienkiewicz 《Central European Journal of Biology》2011,6(3):405-413
The aim of this work was to investigate the antimicrobial properties of thyme essential oil against clinical multiresistant
strains of Acinetobacter spp. The antibacterial activity of oil was tested against standard and clinical bacterial strains of Acinetobacter genus. The agar diffusion method was used to check the inhibition of microbial growth at various concentrations of the oil
from Thymus vulgaris. Susceptibility testing to antibiotics and chemotherapeutics was prepared using the disc-diffusion method. Identification
of bacterial strains was carried out with the Vitek system and confirmed by PCR for Acinetobacter baumanii gyrB gene. The results of experiments showed that the oil from T. vulgaris exhibited an extremely strong activity against all of the clinical strains of Acinetobacter. Thyme oil demonstrated a very good efficacy against multiresistant strains of tested bacteria. Essential oils seems to be
an excellent alternative for synthetic preparations and that is reason for an extensive assessment of their antimicrobial
activity.
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6.
Éva Hideg 《Central European Journal of Biology》2008,3(3):273-284
Four fluorescent singlet oxygen sensors: DanePy, its oxalate salt, Singlet Oxygen Sensor Green and MVP, were infiltrated into
tobacco leaves and tested for toxicity, subcellular localization, light sensitivity and capacity to trap the singlet oxygen
produced in photoinhibition. For reference, a broad sensitivity free radical probe, TEMPO-9-AC, was also included. Photochemical
yield was approximately 15% and 10% inhibited by Singlet Oxygen Sensor Green and MVP, respectively, but was not significantly
affected by the other probes. Under photoinhibitory conditions, brought about by irradiating lincomycin-treated leaves with
strong photosynthetically active radiation, DanePy and Singlet Oxygen Sensor Green were responsive. Singlet Oxygen Sensor
Green was also reactive to low, non-photoinhibitory light exposure of the leaf, which was not characteristic to the other
probes. MVP did not respond to singlet oxygen which can partly be explained by a possible attenuation of its blue emission
in the leaf, as shown by the example TEMPO-9-AC. DanePy-oxalate did not respond to photosynthetic singlet oxygen due to lack
of its penetration into photosynthetic tissue and hence could be useful in detecting any singlet oxygen which escapes from
a chloroplast initiation site. DanePy was localized in the chloroplasts, while Singlet Oxygen Sensor Green was mainly found
in the epidermal cells preferentially associated with the nucleus.
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7.
8.
The lipopolysaccharide (LPS) of Escherichia coli M-17 was isolated, studied, chemically identified, and shown to be an apyrogenic compound of low toxicity. Investigation of the effect of this LPS on T- and B-lymphocytes suggests that it can be used as a mitogen in blast transformation reactions, as it is only slightly less active than the commercial preparation. Double immunodiffusion in agar by Ouchterlony revealed that the LPS of E. coli M-17 in a homologous system exhibited an antigenic activity and did not interact with the antisera against representatives of other Enterobacteriaceae species (Budvicia aquatica, Rahnella aquatilis, and Pragia fontium) in serological cross-reactions. Mild acid hydrolysis yielded the following structural components of the lipopolysaccharide molecule: lipid A, core oligosaccharide, and O-specific polysaccharide. The structure of the O-specific polysaccharide determined using the data on the monosaccharide composition and the 1H and 13NMR spectra was found to be typical of representatives of the E. coli serogroup O2: 相似文献
9.
Akiko Takenaka-Uema Norasuthi Bangphoomi Chieko Shioda Kazuyuki Uchida Fumihiro Gen Kentaro Kato Takeshi Haga Shin Murakami Hiroomi Akashi Taisuke Hoimoto 《中国病毒学》2016,31(3):274-277
正Dear Editor,Akabane virus(AKAV),an orthobunyavirus,is transmitted primarily by biting midges and is widely distributed throughout the world except the Europe.AKAV was first isolated from mosquitoes in Japan(Oya et al.,1961).Although pregnant cows,ewes,and goats infected with AKAV exhibit no clinical signs of disease,in utero infections result in abortion,premature birth,stillbirth,and 相似文献
10.
<正>Dear Editor,The main limitation of the viral pathogenesis study of human gammaherpesviruses Epstein-Barr virus(EBV)and Kaposi sarcoma-associated herpesvirus(KSHV)is the absence of animal model owing to the narrow host tropism of both EBV and KSHV.Murine gammaherpesvirus 68(MHV68)encodes several genes involved in 相似文献
11.
Yongxia Shi Kui Zheng Xiaobo Li Liqiang Li Shufen Li Jinmin Ma Jun Dai Jingkai Ji Shuai Yuan Haorong Lu Jiandong Li Fangfang Sun Xun Xu Jicheng Huang 《中国病毒学》2017,32(3):253-256
<正>Dear Editor,Rift Valley fever(RVF)is an anthropozoonosis caused by Rift Valley fever virus(RVFV).RVFV belongs to the Phlebovirus genus in the family Bunyaviridae,which is circulating among ruminants.Human infection with RVFV is generally asymptomatic,however,minority of patients develop severe RVF diseases like encephalitis or 相似文献
12.
正Dear Editor,Since April 2010,an outbreak of a new disease has elicited symptoms of high fever,loss of appetite,and reduction in egg production in layer ducks in eastern China;this phenomenon has now spread throughout China(Cao et al.,2011;Su et al.,2011).The causative agent of the disease was identified as Tembusu virus(TMUV),which was classified into the genus Flavivirus, 相似文献
13.
<正>Dear Editor,Hepatitis C virus(HCV)is a positive-strand RNA virus that belongs to the genus Hepacivirus within the Flaviviridae family.HCV causes chronic liver diseases,and185 million people are infected(Messina et al.,2015).Currently,there is no approved vaccine to prevent hepatitis C.HCV induces autophagy through elevating reactive oxygen species(ROS)levels via the unfolded 相似文献
14.
Peter R. Bahn Aristotel Pappelis John Bozzola 《Origins of life and evolution of the biosphere》2006,36(5-6):617-619
One of the most prominent amino acids to appear in monomer-generating origin-of-life experiments is aspartic acid. Hugo Schiff
found in 1897 that aspartic acid polymerizes when heated to form polyaspartylimide which hydrolyzes in basic aqueous solution
to form thermal polyaspartic acid which is a branched polypeptide. We recently reported at the ISSOL 2005 Conference that
commercially made thermal polyaspartic acid forms microspheres when heated in boiling water and allowed to cool. In a new
experiment we heated aspartic acid at 180°C for up to 100 h to form thermal polyaspartylimide which when heated in boiling
water without addition of base hydrolyzed to form thermal polyaspartic acid which upon cooling formed microspheres. Thermal
polyaspartic acid microspheres appear protocell-like in the sense of being prebiotically plausible lattices or containers
that could eventually have been filled with just the right additions of primordial proteins, nucleic acids, lipids, and metabolites
so as to constitute protocells capable of undergoing further chemical and biological evolution. Thermal polyaspartic acid
microspheres are extremely simple models of protocells that are more amenable to precise quantitative experimental investigation
than the proteinoid microspheres of Sidney W. Fox. We present here scanning electron microscope images of such thermal polyaspartic
acid microspheres. Figure 1 shows thermal polyaspartic acid microspheres from l-aspartic acid heated at 180°C for 50 h, at a magnification of 3,500×. Figure 2 shows thermal polyaspartic acid microspheres from the same sample at a magnification of 7,000×. The thermal polyaspartic
acid microspheres have a diameter of approximately 1 μm These images were viewed with a Hitachi S2460N scanning electron microscope
at 20 kV acceleration voltage.
Figure 1 Thermal polyaspartic acid microspheres from l-aspartic acid heated at 180°C for 50 h, at a magnification of 3,500×.
Figure 2 Thermal polyaspartic acid microspheres from l-aspartic acid heated at 180°C for 50 h, at a magnification of 7,000×.
Presented at: National Workshop on Astrobiology: Search for Life in the Solar System, Capri, Italy, 26 to 28 October, 2005. 相似文献
Figure 2 Thermal polyaspartic acid microspheres from l-aspartic acid heated at 180°C for 50 h, at a magnification of 7,000×.
Presented at: National Workshop on Astrobiology: Search for Life in the Solar System, Capri, Italy, 26 to 28 October, 2005. 相似文献
15.
Hantaviruses are comprised of tri-segmented negative sense single-stranded RNA, and are members of the Bunyaviridae family. Hantaviruses are distributed worldwide and are important zoonotic pathogens that can have severe adverse effects in humans. They are naturally maintained in specific reservoir hosts without inducing symptomatic infection. In humans, however, hantaviruses often cause two acute febrile diseases, hemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (HCPS). In this paper, we review the epidemiology and epizootiology of hantavirus infections worldwide.
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16.
1. The aphids Dysaphis plantaginea Passerini, Aphis spp. (Aphis pomi De Geer and Aphis spiraecola Patch), and Eriosoma lanigerum Hausmann are commonly found together in apple orchards. Ants establish a mutualistic relationship with the myrmecophilous aphids D. plantaginea and Aphis spp. but not with E. lanigerum. 2. Field surveys and one experiment manipulating the presence of ants and the aphid species were conducted to test the hypothesis that ants play a role in structuring the community of these aphids on apple. 3. Ants tended D. plantaginea and Aphis spp. but not E. lanigerum colonies. In the field, D. plantaginea performed better in the presence of ants while no effect was observed in Aphis spp. Contrarily, populations of Aphis spp. in the manipulative experiment performed better in the presence of ants while no differences were observed for D. plantaginea. Such differences between field and manipulative conditions could be related to thermal tolerance, phenology, and life cycles. In contrast, populations of E. lanigerum were reduced in the presence of ants. 4. Ants also had a significant negative effect on the abundance of natural enemies, which could partially explain the benefits to the tended aphids. However, while ants did not provide a benefit to Aphis spp. when it was reared alone, in the presence of other species ant attendance increased Aphis abundance by 256% and simultaneously reduced E. lanigerum abundance by 63%. Therefore, ants benefited Aphis by reducing competition with other aphid species, which involves a different mechanism, explaining the benefit of ant attendance. Considering all the aphid species together, ants had a net positive effect on aphid abundance, which was consequently considered harmful for the plant. 5. Our results highlighted the role that ants play in structuring apple aphid communities and give support to the observed pattern that ants can benefit tended aphids while simultaneously reducing the abundance of untended herbivores. 相似文献
17.
Yuhai Bi Jianjun Chen Zhenjie Zhang Mingxin Li Tianlong Cai Kirill Sharshov Ivan Susloparov Alexander Shestopalov Gary Wong Yubang He Zhi Xing Jianqing Sun Di Liu Yingxia Liu Lei Liu Wenjun Liu Fumin Lei Weifeng Shi George F. Gao 《中国病毒学》2016,31(4):300-305
A novel Clade 2.3.2.1c H5N1 reassortant virus caused several outbreaks in wild birds in some regions of China from late 2014 to 2015. Based on the genetic and phylogenetic analyses, the viruses possess a stable gene constellation with a Clade 2.3.2.1c HA, a H9N2-derived PB2 gene and the other six genes of Asian H5N1-origin. The Clade 2.3.2.1c H5N1 reassortants displayed a high genetic relationship to a human H5N1 strain (A/Alberta/01/2014). Further analysis showed that similar viruses have been circulating in wild birds in China, Russia, Dubai (Western Asia), Bulgaria and Romania (Europe), as well as domestic poultry in some regions of Africa. The affected areas include the Central Asian, East Asian-Australasian, West Asian-East African, and Black Sea/Mediterranean flyways. These results show that the novel Clade 2.3.2.1c reassortant viruses are circulating worldwide and may have gained a selective advantage in migratory birds, thus posing a serious threat to wild birds and potentially humans. 相似文献
18.
<正>This special issue of the journal is dedicated to the recent research progress on human herpesviruses(HHVs).Human herpesviruses are distributed worldwide,and more than 90%of adults are infected by one or multiple HHVs.The HHV family contains three sub-families:the alpha sub-family[herpes simplex virus 1(HSV-1),HSV-2, 相似文献
19.
An effective vaccine for human immunodeficiency virus (HIV) is urgently needed to prevent HIV infection and progression to acquired immune deficiency syndrome (AIDS). As glycosylation of viral proteins becomes better understood, carbohydrate-based antiviral vaccines against special viruses have attracted much attention. Significant efforts in carbohydrate synthesis and immunogenicity research have resulted in the development of multiple carbohydrate-based HIV vaccines. This review summarizes recent advances in synthetic carbohydrate-based vaccines design strategies and the applications of these vaccines in the prevention of HIV. 相似文献
20.
Host range of a newly introduced parasitoid, Binodoxys communis among common aphid species in Hawaii
Binodoxys communis (Gahan) (Hymenoptera:Braconidae), a parasitoid of aphids originally from China, was introduced into Hawaii and evaluated in the laboratory for its ability to detect, accept, oviposit and develop in Aphis gossypii reared on two host plants, plus five other common aphid species. The parasitoid was able to detect all six aphid species and to successfully sting five species, with highest preference for those in the genus Aphis. Aphis species were highly suitable for parasitoid development. Other species were only marginally suitable. Parasitoids spent less time searching on plants of less acceptable aphids. Aphid defensive behaviors did not affect oviposition success, but did lengthen the parasitoid’s handling time of several aphid species. Host acceptance was positively correlated with host suitability, yet one unsuitable host was readily accepted for oviposition. 相似文献