Although variola virus (VARV) has been eradicated through widespread vaccination, other
pathogenic for humans circulate in nature. Recently, new
, including some able to infect humans, have been ...found and their complete genomes have been sequenced. Questions about the
mutation rate and the emergence of new threats to humankind as a result of the evolution of circulating
remain open. Based on contemporary data on ancient VARV DNA and DNA of new
species, an analysis of the molecular evolution of
was carried out and the timescale of their emergence was estimated. It was calculated that the
of the Old and New Worlds separated approximately 40,000 years ago; the recently discovered Akhmeta virus and Alaskapox virus separated from other
approximately 10,000-20,000 years ago; the rest of modern orthopoxvirus species originated from 1700 to 6000 years ago, with the exception of VARV, which emerged in approximately 300 AD. Later, there was a separation of genetic variants of some
species, so the monkeypox virus West African subtype originated approximately 600 years ago, and the VARV minor alastrim subtype emerged approximately 300 years ago.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
In this paper, we propose a new, effective, and easy-to-implement technology for hydrothermal synthesis of an adsorption material based on carboxymethylcellulose (CMC) and graphene oxide (GO) ...decorated with iron nanoparticles (FeNPs) for water purification from heavy metals. The purpose was to study the effect of the iron content in the materials on their physicochemical and adsorption properties. The synthesized materials were examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. Complex adsorption studies were performed using the example of lead ion removal from contaminated aqueous media. The influence of pH and contact time on the process efficiency was studied. The mechanism of adsorption was analyzed using pseudo first-order and pseudo second-order, intraparticle diffusion, and Elovich kinetics models. The results showed an optimal pH of 6 and contact time of 30 min. The process is best described by a pseudo second-order model. The material with a mass content of iron nanoparticles of 18% (CMC/GO + Fe 18 wt%) showed the largest adsorption capacity for Pb ions (1850 mg g−1). Adsorption isotherms of lead ions from aqueous media by the synthesized composite materials were studied using Dubinin–Radushkevich and BET models. The adsorption process is based on the chemical interaction of extracted ions with the surface of an adsorbent. Desorption studies showed the possibility of using the GO/CMC/FeNPs in real processes for purification of aqueous media. The obtained maximum value of adsorption capacity for the CMC/GO + Fe 18 wt% material was 1850 mg g−1, which is one of the highest in the literature for composite materials based on GO and vegetable raw material processing products.
Display omitted
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The synchronism and asynchrony of variations in the annual runoff for the 18 largest rivers (153 river pairs) in the Asian part of Russia have been assessed using a novel original technique. The ...technique is based on taking three groups of river water discharge (low-, average-, and high-water years) into account and on the numeric rating of the runoff in the years compared. The runoff of the rivers is assigned to a particular group of water discharge by using its long-term average annual value. The years in which the runoff was less than 0.95 of its long-term average annual value are assigned to the low-water years; when it is more than 1.05, they are added to the high-water years. The average-water years include the runoff values from the 0.95–1.05 interval of the long-term average annual value. The runoff in the low-, average- and high-water years is identified by numbers 1, 2, and 3, respectively. A comparison of water discharges is made for all 153 pairs of river basins over the correlative observation periods under investigation. The years of identical water discharge (1–1, 2–2, 3–3) are assigned the number 1; the years with opposite water discharge (1–3, 3–1) are characterized by the number –1, and the years of similar water discharge (1–2, 2–1, 2–3, 3–2) are identified by the number 0.5. For each pair of rivers, the numeric sum expressed in fractions of the total period of observation is calculated, which is the parameter of synchronism (asynchrony) of runoff variations. For 18 pairs of the river basins, the values of the synchronism parameter are equal to or more than 0.5. For these pairs of the rivers, it is determined that the average contributions of the low-, high- and average-water years to synchronism are 45.1, 36.3, and 10.7%, respectively. The years of adjacent discharges increase the synchronism parameter by 29.2%, while the years with opposite discharges decrease synchronism by 21.3%. The synchronism is also assessed by using the correlation method.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
A novel polyaniline-modified CNT and graphene-based nanocomposite (2.32–7.34 nm) was prepared and characterized by spectroscopic methods. The specific surface area was 176 m2/g with 0.232 cm3/g as ...the specific pore volume. The nanocomposite was used to remove zinc and lead metal ions from water; showing a high removal capacity of 346 and 581 mg/g at pH 6.5. The data followed pseudo-second-order, intraparticle diffusion and Elovich models. Besides this, the experimental values obeyed Langmuir and Temkin isotherms. The results confirmed that the removal of lead and zinc ions occurred in a mixed mode, that is, diffusion absorption and ion exchange between the heterogeneous surface of the sorbent containing active adsorption centers and the solution containing metal ions. The enthalpy values were 149.9 and 158.6 J.mol−1K−1 for zinc and lead metal ions. The negative values of free energies were in the range of −4.97 to −26.3 kJ/mol. These values indicated an endothermic spontaneous removal of metal ions from water. The reported method is useful to remove the zinc and lead metal ions in any water body due to the high removal capacity of nanocomposite at natural pH of 6.5. Moreover, a low dose of 0.005 g per 30 mL made this method economical. Furthermore, a low contact time of 15 min made this method applicable to the removal of the reported metal ions from water in a short time. Briefly, the reported method is highly economical, nature-friendly and fast and can be used to remove the reported metal ions from any water resource.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
We suggest a method for assessing the presence of groups of years with low, medium, and high discharges in the flow of major rivers in Asian Russia for a particular observing period. The river ...discharge is associated with a particular group of discharge by using its average long-term value. The years with discharges smaller than 0.95 or larger than 1.05 of its average long-term value are referred to as low or high discharge rivers, respectively. The years with medium discharge include values of discharge varying from 0.95 to 1.05 of the average long-term value. It is found that the discharges of the eight major rivers of Asian Russia (Ob, Yenisei, Lena, Yana, Indigirka, Kolyma, Amur, and Kamchatka) relatively often include groups of rivers with different discharges: low, medium, and high. Most often the length of these groups varies from 2 to 5 years. However, the runoff of the Amur River showed groups of low and high discharges with a length of 10 years. The discharge of the Indigirka River showed one group with a length of 9 years. The proportion of coeval groups not included in groups of years of different discharges, with respect to the total number of years, was as follows: the Ob, 23.5%; Yenisei, 45%; Lena 43%; Yana, 28.8%; Indigirka, 26.7%; Kolyma, 30.2%; Amur, 38.7%; and Kamchatka, 36.1%. The probability a change of years with a particular discharge for other discharges is assessed. It is established that, in the runoff of the rivers of Asian Russia, the probabilities for only years with low and high discharges to persist are the highest.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Diversity-generating retroelements (DGRs) are prokaryotic systems providing rapid modification and adaptation of target proteins. In phages, the main targets of DGRs are receptor-binding proteins ...that are usually parts of tail structures and the variability of such host-recognizing structures enables phage adaptation to changes on the bacterial host surface. Sometimes, more than one target gene containing a hypermutated variable repeat (VR) can be found in phage DGRs. The role of mutagenesis of two functionally different genes is unclear. In this study, several phage genomes that contain DGRs with two target genes were found in the gut virome of healthy volunteers. Bioinformatics analysis of these genes indicated that they encode proteins with different topology; however, both proteins contain the C-type lectin (C-lec) domain with a hypermutated beta-hairpin on its surface. One of the target proteins belongs to a new family of proteins with a specific topology: N-terminal C-lec domain followed by one or more immunoglobulin domains. Proteins from the new family were named tentaclins after TENTACLe + proteIN. The genes encoding such proteins were found in the genomes of prophages and phages from the gut metagenomes. We hypothesized that tentaclins are involved in binding either to bacterial receptors or intestinal/immune cells.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
7.
The origin of the variola virus Babkin, Igor V; Babkina, Irina N
Viruses,
03/2015, Volume:
7, Issue:
3
Journal Article, Book Review
Peer reviewed
Open access
The question of the origin of smallpox, one of the major menaces to humankind, is a constant concern for the scientific community. Smallpox is caused by the agent referred to as the variola virus ...(VARV), which belongs to the genus Orthopoxvirus. In the last century, smallpox was declared eradicated from the human community; however, the mechanisms responsible for the emergence of new dangerous pathogens have yet to be unraveled. Evolutionary analyses of the molecular biological genomic data of various orthopoxviruses, involving a wide range of epidemiological and historical information about smallpox, have made it possible to date the emergence of VARV. Comparisons of the VARV genome to the genomes of the most closely related orthopoxviruses and the examination of the distribution their natural hosts' ranges suggest that VARV emerged 3000 to 4000 years ago in the east of the African continent. The VARV evolution rate has been estimated to be approximately 2 × 10-6 substitutions/site/year for the central conserved genomic region and 4 × 10-6 substitutions/site/year for the synonymous substitutions in the genome. Presumably, the introduction of camels to Africa and the concurrent changes to the climate were the particular factors that triggered the divergent evolution of a cowpox-like ancestral virus and thereby led to the emergence of VARV.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
CrAss-like phages play an important role in maintaining ecological balance in the human intestinal microbiome. However, their genetic diversity and lifestyle are still insufficiently studied. In this ...study, a novel CrAssE-Sib phage genome belonging to the epsilon crAss-like phage genomes was found. Comparative analysis indicated that epsilon crAss-like phages are divided into two putative genera, which were proposed to be named
and
; CrAssE-Sib belongs to the former. The crAssE-Sib genome contains a diversity-generating retroelement (DGR) cassette with all essential elements, including the reverse transcriptase (RT) and receptor binding protein (RBP) genes. However, this RT contains the GxxxSP motif in its fourth domain instead of the usual GxxxSQ motif found in all known phage and bacterial DGRs. RBP encoded by CrAssE-Sib and other
has an unusual structure, and no similar phage proteins were found. In addition, crAssE-Sib and other
encode conserved prophage repressor and anti-repressors that could be involved in lysogenic-to-lytic cycle switches. Notably, DNA primase sequences of epsilon crAss-like phages are not included in the monophyletic group formed by the DNA primases of all other crAss-like phages. Therefore, epsilon crAss-like phage substantially differ from other crAss-like phages, indicating the need to classify these phages into a separate family.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
was discovered as a soil bacterium associated with the rhizosphere. Later,
was found to be a multidrug-resistant hospital-associated pathogen. Lytic bacteriophages are prospective antimicrobials; ...therefore, there is a need for the isolation and characterization of new
phages. The phage StenM_174 was isolated from litter at a poultry farm using a clinical strain of
as the host. StenM_174 reproduced in a wide range of clinical and environmental strains of
, mainly
, and it had a podovirus morphotype. The length of the genomic sequence of StenM_174 was 42,956 bp, and it contained 52 putative genes. All genes were unidirectional, and 31 of them encoded proteins with predicted functions, while the remaining 21 were identified as hypothetical ones. Two tail spike proteins of StenM_174 were predicted using AlphaFold2 structural modeling. A comparative analysis of the genome shows that the
phage StenM_174, along with the phages Ponderosa, Pepon, Ptah, and TS-10, can be members of the new putative genus
in the
family. In addition, the analyzed data suggest a new subfamily within this family.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Display omitted
•Low melting siloxane- and phosphate-bridged phthalonitrile monomers are reported.•Computational model aimed to predict monomers Tg is developed.•Cured resins demonstrate excellent ...thermal performance featured to phthalonitriles.
The series of low-melting siloxane- and phosphate-bridged phthalonitriles are studied. The monomers of this type possess glass transition temperatures more than 100°C lower than for common phthalonitriles. Based on the collected experimental data molecular dynamics simulations aimed to predict glass-transition temperatures of the considered types of low-melting phthalonitriles are reported. The validity of computational model is confirmed by successful synthesis of the new monomers, e.g. phosphate- and phosphonate-bridged phthalonitriles are introduced for a first time. Cured Bis(3-(3,4-dicyanophenoxy)phenyl) phenyl phosphate demonstrates thermal performance featured to phthalonitriles (HDT∼450°C, T5%=524°C, Yc, (Ar)=80%) along with increased thermo-oxidative stability. In aggregate with convenient processing the considered phthalonitriles can be used as high-temperature matrices for fiber-reinforced plastics production by vacuum infusion or RTM techniques.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
PDF
