DNA sequencing remains one of the most important problems in molecular and computational biology. One of the methods used for this purpose is sequencing by hybridization. In this approach usually DNA chips composed of a full library of oligonucleotides of a given length are used, but in principle it is possible to use another types of chips. Isothermic DNA chips, being one of them, when used for sequencing may reduce hybridization error rate. However, it was not clear if a number of errors following from subsequence repetitions is also reduced in this case. In this paper a method for estimating resolving power of isothermic DNA chips is described which allows for a comparison of such chips and the classical ones. The analysis of the resolving power shows that the probability of sequencing errors caused by subsequence repetitions is greater in the case of isothermic chips in comparison to their classical counterparts of a similar cardinality. This result suggests that isothermic chips should be chosen carefully since in some cases they may not give better results than the classical ones.
The Bulletin of the Polish Academy of Sciences: Technical Sciences (Bull.Pol. Ac.: Tech.) is published bimonthly by the Division IV Engineering Sciences of the Polish Academy of Sciences, since the beginning of the existence of the PAS in 1952. The journal is peer‐reviewed and is published both in printed and electronic form. It is established for the publication of original high quality papers from multidisciplinary Engineering sciences with the following topics preferred: Artificial and Computational Intelligence, Biomedical Engineering and Biotechnology, Civil Engineering, Control, Informatics and Robotics, Electronics, Telecommunication and Optoelectronics, Mechanical and Aeronautical Engineering, Thermodynamics, Material Science and Nanotechnology, Power Systems and Power Electronics.
Journal Metrics: JCR Impact Factor 2018: 1.361, 5 Year Impact Factor: 1.323, SCImago Journal Rank (SJR) 2017: 0.319, Source Normalized Impact per Paper (SNIP) 2017: 1.005, CiteScore 2017: 1.27, The Polish Ministry of Science and Higher Education 2017: 25 points.
Abbreviations/Acronym: Journal citation: Bull. Pol. Ac.: Tech., ISO: Bull. Pol. Acad. Sci.-Tech. Sci., JCR Abbrev: B POL ACAD SCI-TECH Acronym in the Editorial System: BPASTS.
In the paper, the problem of isothermic DNA sequencing by hybridization, without any errors in its input data, is presented and an exact polynomial-time algorithm solving the problem is described. The correctness of the algorithm is con.rmed by an enumerative proof.
The subject of the numerical investigation is an ellipsoidal head with a central (axis-symmetrical) nozzle. The nozzle is loaded by axial load force. The ellipsoidal head is under axial-symmetrical compression load. The numerical FEM model is elaborated. The calculation will provide the critical loads and equilibrium paths for the sample head.. The investigation will measure the influence of the diameter of the nozzle on the critical state of the ellipsoidal head.
Silver nanoparticles (AgNPs) are widely used in numerous industries and areas of daily life, mainly as antimicrobial agents. The particles size is very important, but still not suffi ciently recognized parameter infl uencing the toxicity of nanosilver. The aim of this study was to investigate the cytotoxic effects of AgNPs with different particle size (~ 10, 40 and 100 nm). The study was conducted on both reproductive and pulmonary cells (CHO-9, 15P-1 and RAW264.7). We tested the effects of AgNPs on cell viability, cell membrane integrity, mitochondrial metabolic activity, lipid peroxidation, total oxidative and antioxidative status of cells and oxidative DNA damage. All kinds of AgNPs showed strong cytotoxic activity at low concentrations (2÷13 μg/ml), and caused an overproduction of reactive oxygen species (ROS) at concentrations lower than cytotoxic ones. The ROS being formed in the cells induced oxidative damage of DNA in alkaline comet assay. The most toxic was AgNPs<10 nm. The results indicate that the silver nanoparticles, especially less than 10 nm, may be harmful to the organisms. Therefore, risk should be considered when using nanosilver preparations and provide appropriate protective measures when they are applied.
The excessive use of pesticides is a problem in most parts of the world today because of their broad and unspecific target range that is considerably harmful. The accumulation of several chemical insecticide residues based on chlorpyrifos-methyl, organochlorine, different isomers of HCH, DDT etc., in Triticum aestivum L. plants can be dangerous. Hence, there is an urgent need to develop potential and safer alternative measures. Wheat (Triticum aestivum L.) is a major cereal crop grown and used for food, animal feed, beverages and furniture accessories in most parts of the world. It also serves as a host to various insect pests. Our previous studies showed the insecticidal potency and specificity of short ssDNA oligonucleotides from the inhibitor of apoptosis (IAP-2 and IAP-3) genes of Lymantria dispar multicapsid nuclear polyhedrosis virus (LdMNPV) against gypsy moth (L. dispar) larvae, a possible insect pest of non-host plants like wheat. Consequently, the present study analyzes the effects of ssDNA oligonucleotides used as DNA insecticides on wheat (T. aestivum) plant biomass, plant organs and some biochemical parameters as a marker of the safety margin on non-target organisms. The results obtained on plant biomass showed that groups treated with ssDNA oligonucleotides at concentrations of 0.01 pmol · μl−1, 0.1 pmol · μl−1 and 1 pmol · μl−1 varied in comparison with the control group, but remained harmless to plant growth and development, while the treatment concentration of 0.001 pmol · μl−1 did not affect the plant biomass. The glucose, protein and phosphorous biochemical parameters, analyzed after 21 days, showed that the ssDNA oligonucleotides used were equally safe. The data obtained for the plant organs (leaves and root lengths) indicate that the phenomenon of DNA insecticides can be further studied and developed for plant protection while improving the growth of plant organs even for a non-target organism such as wheat T. aestivum plants.
Dissipative Particle Dynamics (DPD) is a simulation method at mesoscopic scales that bridges the gap between molecular dynamics and continuum hydrodynamics. It can simulate efficiently complex liquids and dense suspensions using only a few thousands of virtual particles and at speed-up factors of more than one hundred thousands compared to Molecular Dynamics. Lowe’s approach provides a powerful alternative to the usual DPD integrating schemes. Here, we demonstrate the details and potential of Lowe’s scheme. We compute viscosity, diffusivity and Schmidt number values and we present comparison of wormlike chain models under shear with experimental and Brownian Dynamics results for ll-phage DNA.
The study of liquid crystalline assemblies, with an emphasis on biological phenomena, is now accessible using newly developed microdevices integrated with X-ray analysis capability. Many biological systems can be described in terms of gradients, mixing, and confinement, all of which can be mimicked with the use of appropriate microfluidic designs. The use of hydrodynamic focusing creates well-defined mixing conditions that vary depending on parameters such as device geometry, and can be quantified with finite element modelling.We describe experiments in which geometry and strain rate induce finite changes in liquid crystalline orientation. We also demonstrate the online supramolecular assembly of lipoplexes. The measurement of lipoplex orientation as a function of flow velocity allows us to record a relaxation process of the lipoplexes, as evidenced by a remarkable 4-fold azimuthal symmetry. All of these processes are accessible due to the intentional integration of design elements in the microdevices.
We analyzed DNA damage, mitotic activity and polyploidization in Crepis capillaris callus cells during short- and long-term in vitro culture, and the influence of plant growth regulators on these processes. Changes in the concentration of growth regulators altered the stability of callus. The level of DNA damage was highly dependent on the growth regulator composition of the medium. Cytokinin at high concentrations damaged DNA in the absence of auxin. Short- and long-term callus differed in sensitivity to growth regulators. Mitotic activity changed when callus was transferred to medium with modified growth regulators. Callus cell nuclear DNA content increased with age and in response to plant growth regulators. Hormones played a role in the genetic changes in C. capillaris callus culture. We demonstrated the usefulness of C. capillaris callus culture as a model for analyzing the effect of culture conditions, including plant growth regulators, on genetic stability.
We used artificial hybridization to study the crossability of the noble fir (Abies procera) with Manchurian fir (A. holophylla) and Caucasian fir (A. nordmanniana), and found compatibility between A. procera of North American origin and the Asian species A. holophylla as evidenced by the 14% fraction of filled seeds obtained in A. procera × A. holophylla crossing. Crossing of A. procera with the Mediterranean species A. nordmanniana failed completely, producing only empty seeds.
Intraspecific changes in genome size and chromosome number lead to divergence and species evolution. Heavy metals disturb the cell cycle and cause mutations. Areas contaminated by heavy metals (metalliferous sites) are places where microevolutionary processes accelerate: very often only a few generations are enough for a new genotype to arise. This study, which continues our long-term research on Viola tricolor (Violaceae), a species occurring on both metalliferous (Zn, Pb, Cd, Cu) and non-metalliferous soils in Western and Central Europe, is aimed at determining the influence of environments polluted with heavy metals on genome size and karyological variability. The genome size of V. tricolor ranged from 3.801 to 4.203 pg, but the differences between metallicolous and non-metallicolous populations were not statistically significant. Altered chromosome numbers were significantly more frequent in material from the polluted sites than from the non-polluted sites (43% versus 28%). Besides the standard chromosome number (2n = 26), aneuploid cells with lower (2n = 18-25) or higher (2n = 27, 28) chromosome numbers were found in plants from both types of site, but polyploid (2n = 42) cells were observed only in plants from the metalliferous locality. The lack of correlation between chromosome variability in root meristematic cells and genome size estimated from peduncle cells can be attributed to elimination of somatic mutations in generative meristem, producing chromosome-stable non-meristematic tissues in the peduncle.