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.

Feeder cells can promote cell proliferation and help overcome the developmental arrest of early embryos by producing growth factors. The objective of this study was to evaluate the effects of feeder cells on the development of all single porcine parthenogenetic embryos in vitro. Firstly, we showed that the cleavage and blastocyst formation rate of all single procine parthenogenetic embryos co-cultured with feeder cells increased in contrast to those cultured without feeder cells (p<0.05). However, no statistically significant differences were observed between the blastocyst formation rate in the embryos co-cultured with 3 different kinds feeder cells namely oviduct epithelial feeder cells, granulose feeder cells and porcine fetal fibroblast feeder cells (p>0.05). Secondly, highly significant differences were observed between the cleavage and blastocyst formation rate (p<0.05) when the embryos were co-cultured with oviduct epithelial feeder cells in different volume drops ranging from 3 to 20 μL and the cleavage rate were the highest when cultured in 5 μL drops. Thirdly, the tempospacial pattern of the development of single embryos co-cultured with oviduct epithelial feeder cells was consistent with that of traditional multi-embryo culture, indicating that the co-culturing does not affect the developmental competence of the porcine parthenogenetic embryos. Finally, highly significant differences were observed between the cleavage and blastocyst formation rate with and without zona pellucida in vitro (p<0.05). In this study, a new adaption of in vitro co-culture of single porcine parthenogenetic embryos using feeder cells has been successfully established and this will facilitate further investigations to discover the mechanistic mode of developmental arrest of porcine embryos.

Culture gas atmosphere is one of the most important factors affecting embryo development in vitro. The main objective of this study was to compare the effects of CO concentration on the subsequent pre-implantation developmental capacity of pig embryos in vitro, including embryos obtained via parthenogenesis, in vitro fertilization (IVF), and intracytoplasmic sperm injection (ICSI). Pig embryos were developed in four different CO2 concentrations in air: 3%, 5%, 10%, or 15%. The cleavage rate of pig parthenogenetic, IVF, or ICSI embryos developed in CO2 concen- trations under 5% was the highest. There were no significant differences in the oocyte cleavage rate in ICSI embryos in CO2 concentrations under 3% and 5% (p>0.05). However, as CO2 levels increased (up to 15%) the blastocyst output on day 7, from parthenogenetic, IVF, and ICSI em- bryos, decreased to 0%. These findings demonstrate that CO2 positively affects the developmen- tal capacity of pig embryos. However, high or low CO2 levels do not significantly improve the developmental capacity of pig embryos. The best results were obtained for all of the pig embryos at a 5% CO2 concentration.

Roots of Codonopsis pilosula (Franch.) Nannf. are among the most popular Chinese herbal medicines, exhibiting various beneficial activities which support immunity and stress resistance. The plant shows high intraspecific genetic variation. There is a need for effective vegetative propagation methods yielding high and sustainable quality. Here we report a micropropagation method using axillary shoot proliferation. Nodal segments from aseptically germinated plants were inoculated on modified MS media enriched with different concentrations of cytokinins: benzyladenine, kinetin (1, 4, 10 or 20 μM) or thidiazuron (1, 4 or 8 μM), with or without the auxin NAA (1 μM). Axillary bud break was initiated most efficiently on media with 1 or 4 μM BA and 1μM NAA. Shoot number increased markedly in subsequent cycles of harvesting and transfer to fresh 1 μM BA and NAA medium, leading to the maximum 69 shoots (mean 38.16±4.35) from a single nodal explant in the fourth harvest. The shoots were successfully (>98% efficiency) rooted in MS medium containing high sucrose (60 g/L) and 5 μM IAA, and acclimatized to soil cultivation with a survival rate of 90%. These results can be used to establish a simple and commercially viable protocol for mass propagation of C. pilosula for plantations or breeding.

To understand the molecular mechanism controlling in vitro plant morphogenesis, a culture system enabling induction of alternative morphogenic pathways (somatic embryogenesis, SE; shoot organogenesis, ORG) in a well defined population of somatic cells is needed. Arabidopsis is the most useful model plant for genomic studies, but a system in which SE or ORG can be induced alternatively in the same type of explant has not been proposed. Immature zygotic embryos (IZEs) of Arabidopsis provide the only explants with embryogenic potential, and have been recommended for studying mechanisms of SE induced in vitro. This study was aimed at defining culture conditions promoting induction of alternative morphogenic pathways: shoot ORG in IZE explants. The established protocol involves pretreatment of IZE explants with liquid auxin-rich callus induction (CIM) medium, followed by subculture on solid cytokinin-rich shoot induction medium (SIM). The method enables efficient shoot induction in Columbia (Col-0) and Wassilewskija (Ws), genotypes commonly used in molecular studies. During 3 weeks of culture up to 90% of Col-0 and 70% of Ws explants regenerated shoots via an indirect morphogenic pathway. We analyzed the qRT-PCR expression patterns of the LEC (LEC1, LEC2 and FUS3) genes, the key regulators of Arabidopsis embryogenesis, in the IZE explants induced to promote shoot ORG. The sharp decline of LEC expression on SIM medium confirmed that culture of Arabidopsis IZE explants enables experimental manipulation of the morphogenic response of somatic cells. A scheme illustrating various in vitro morphogenic responses of IZEs in relation to hormonal treatment is presented.

Using four Polish Vicia faba L. minor cultivars (Bronto, Dino, Tibo, Nadwiślański) we obtained callus from epicotyl fragments collected from 7- and 14-day-old seedlings and from cotyledonary nodes of immature seeds. Callus induction efficiency varied from 81% to 97% depending on the origin of the explant. Shoots regenerated only from the cotyledonary nodes of all tested cultivars. On average, 50% of the explants grown on MS medium containing 1.0 mg dm-3 NAA, 0.5 mg dm-3 BAP, 0.25 mg dm-3 GA3, 1.0 g dm-3 casein hydrolysate, 750 mg dm-3 inositol, 3% sucrose and 0.4% agar were able to regenerate shoots. The number of calluses regenerating shoots was highest from explants collected from fruiting nodes 6 to 9. Decapitation of donor plants increased the percentage of calluses regenerating shoots. On half-strength MS medium with 2 mg dm-3 NAA and on 1/2 MS alone, 11% of the shoots rooted; on 1/2 MS with 1 g dm-3 AC, 8.0% rooted. The regenerants were transferred to Perlite with Hoagland medium and acclimated. Ten percent of the regenerated plants survived the acclimation process, flowered and produced seeds.

Rye is an important crop widely cultivated in Europe, but one of the hardest to improve due to its allogamy and self-incompatibility. The market for rye-based products is constantly growing thanks to the popularity of organic farming, feed production and diverse industry applications. To address these demands, new highly productive hybrid rye varieties are needed. Currently, full potential of heterosis in rye breeding is hard to reach due to the limited success in in vitro cultures. This review summarizes the progress in rye in vitro cultures and proposes novel approaches to overcome recalcitrance in this species.

Steroidal saponins isolated from many plant species belonging to Monocotyledones display potent cytotoxic activity towards many human tumor cells. We examined the cytotoxic effects of crude Paris quadrifolia extract for the first time, testing isolated saponin-rich fractions against four different human cell lines using the [(3-(4,5-dimethylthiazol-2-yl)]-2,5-diphenyltetrazolium bromide (MTT) assay. Cytotoxic activity was tested against human promyelocytic leukemia (HL-60) cells, human cervical adenocarcinoma (HeLa) cells and human breast cancer (MDA-MB-468) cells. Human skin fibroblasts were used as non-neoplastic control cells. Our results show significant activity of the weakly water-soluble solid residue and butanolic fraction against HL-60 and HeLa cells. The solid residue exerted cytotoxicity against all tested cell lines.

In flowering plants, seeds are produced both sexually (double fertilization is required) and asexually via apomixis (meiotic reduction and egg fertilization are omitted). An apomictic-like pattern of endosperm development in planta is followed by fis mutants of sexual Arabidopsis thaliana. In our experiments in planta, autonomous endosperm (AE) developed in met1 mutants. Furthermore we obtained autonomous endosperm formation in vitro not only in unfertilized ovules of fie mutants but also in wild genotypes (Col-0, MET1/MET1, FIE/FIE) and met1 mutants. AE induction and development occurred in all genotypes on the each of the media used and in every trial. The frequency of AE was relatively high (51.2% ovaries) and genotype-dependent. AE induced in vitro represents a more advanced stage of development than AE induced in fie mutants in planta. This was manifested by a high number of nuclei surrounded by cytoplasm and organized in nuclear cytoplasmic domains (NCDs), nodule formation, division into characteristic regions, and cellularization. The high frequency of AE observed in homozygous met1 (met1/met1) mutants probably is due to accumulation of hypomethylation as an effect of the met1 mutation and the in vitro conditions. AE development was most advanced in FIE/fie mutants. We suggest that changes in the methylation of one or several genes in the DNA of Arabidopsis genotypes caused by in vitro conditions resulted in AE induction and/or further AE development.

An efficient micropropagation system for Taraxacum pieninicum using seedling explants germinated in vitro is described. Shoot tips and fragments of cotyledons, hypocotyls and roots were isolated from several-day-old seedlings. The highest response, 100% frequency with 12.3 axillary shoots/explant, was from shoot tips on medium supplemented with 0.5 mg L-1 BA and 0.05 mg L-1 NAA. In subsequent subcultures the number of shoots was significantly higher on all explants cultured on medium containing 0.25 and 0.5 mg L-1 BA, and the multiplication rate was highest (20 shoots/explant) in the 4th passage. Shoots rooted on MS and 1/2 MS medium; the highest rooting frequency was 90% and the highest number of roots 2.7/shoot. Rooted plants showed 96.2% survival in sterile soil:sand, and 100% survival in hydroponic culture. Regenerated plants flowered in the second year after acclimatization and yielded viable seeds. This protocol for obtaining complete plants through micropropagation may prove useful for conservation of the genetic resources of this and other endangered species

Blastocystis is a common enteric protozoan of humans and various species of animals. Culture and microscopic examination of fecal samples is the conventional method for identifying four major forms of Blastocystis (vacuolar, granular, non-vacuolar or cystic). In this article, we compared eight liquid media for cultivation of Blastocystis spp. Study material included fecal samples from clinically healthy pigs. Significant differences in the growth of Blastocystis on individual media were observed.

The spontaneous diploidization rates in oilseed rape (Brassica napus L.) via in vitro androgenesis are too low for practical applications. In contrast, artificial doubling of chromosomes of the microspore has proven to be more successful and allows homozygous plants to be obtained in a short time. Here, we present the efficiency of diploidization of B. napus haploids using three different chromosome doubling methods.

Using the in vitro approach in microspores, the rate of chromosome doubling in 24 populations of androgenic plants ranged from 15.8% to 94.0%. An alternative in vivo method for the induction of chromosome doubling involves colchicine treatment of young haploid plants, and this yielded doubling rates ranging from 47.5% to 86.4% in 10 different plant populations. Another in vivo method of chromosome doubling is colchicine treatment of the excised young axillary shoots of haploid plants at the early flowering stage. The high efficiency of this method was confirmed in haploid plant populations from 11 genetically distinct donors in which the frequency of occurrence of diploids ranged from 53.3% to 100%. However, in this case, the time required for seed formation from doubled haploids increased by about 3–5 months. The availability of several methods of chromosome doubling at various stages of the androgenic process – from isolated microspores through to young plants and flowering plants – allows seeds to be obtained from nearly every selected individual haploid.

Introduction: Dentin hypersensitivity is a painful clinical condition. The frequency of its occurrence varies from 8 to 57%, depending on tested group and different methods of investigations. Recommended desensitizing agents have different mechanism of action and effectiveness. We are still looking for solutions that will improve their effectiveness and simultaneously allow for wider use of e.g. as a base material, counteracting postoperative hypersensitivity, reducing marginal microleakage. The aim of the study was to assess the effect of a selected desensitizing agent occluding dentin tubules with calcium hydroxyapatite on marginal microleakage formation of a class V composite restorations subjected to thermocycles.

Materials and Methods: In study it was used 40 molars and premolars, which were alternately assigned into two groups. In both groups standardized cavities were prepared. In the study group (study group — SG) before application of bonding agent Teethmate Desensitizer (f. Kuraray, Noritake Dental Inc., Okayama, Japan) was used. In the control group (control group — CG) OptiBond All-in-one (f. Kerr, Bioggio, Switzerland) bonding agent was used and cavities were filled using composite material Gradia Direct (f. GC Europe N.V., Leuven, Belgium). After storage in saline, teeth were subjected to 600 thermo-cycles, passive dye penetration test was done, teeth were cut in the area of filling, according to its long axis. Under light microscope magnification value of microleakage was measured and marginal microleakage rate (M) was counted. The results of the tests were statistically analyzed using the package STATISTICA 12.0 (StatSoft, USA).

Results: The average value of M for the SG group was 0.46 (min 0.05, max 0.76, SD 0.226) and for CG was 0.22 (min 0, max 0.74, SD 0.235). The differences between M values were statistically significant (p = 0.0094).

Conclusion: A reduction in the number of retention sites for the bonding system, facilitates the formation of microleakage in the experimental conditions and reduces the degree of adhesion of the composite material to the hard tissues of the tooth.

In the current study the antifungal activity of inorganic reagents was tested against Cryphonectria parasitica in vitro in a mycelial growth inhibition test. Three reagents, each consisting of chloride silver (AgCl) in combination with (1) aluminum oxide − Al2O3, (2) zinc oxide − ZnO, and (3) Al2O3 and titanium dioxide – TiO2, were tested. Significant differences of the tested reagents on the growth of C. parasitica were recorded. The study demonstrated that silver in mixture with ZnO had an antifungal effect and significantly reduced the mycelial growth of C. parasitica in vitro. The mixture of AgCl with the other two combinations of inorganic metal oxides had no inhibition effect on the growth of the pathogen. It was confirmed that ZnO (applied in a single compound test) is responsible for inhibition of C. parasitica mycelium growth. A preliminary in planta assay was performed but statistically significant differences were not recorded in the average increment of canker length.

The free-living Acanthamoeba sp. causes various diseases. Treatment of them is very difficult and not always effective because of encystation, making it highly resistant to antiamoebic drugs. Gram-positive bacteria Staphylococcus aureus, Gram-negative bacteria Escherichia coli, and an yeast Candida albicans also exhibit outstanding resistance to antimicrobial substances. The search for new natural amoebicidal and antimicrobial agents of plant origin is still of current interest. The aim of the study was to investigate the amoebicidal activity of the extracts obtained from tissue culture and a field-grown plant of Chaenomeles japonica against pathogenic trophozoites of Acanthamoeba spp. and antimicrobial effect against S. aureus, E. coli, and C. albicans. The extracts of C. japonica had an inhibitory effect on the proliferation of Acanthamoeba trophozoites as compared to the non-treated control. Among the crude extracts tested, the extract of leaves, from both shoot culture and the field-grown plant had remarkable amoebicidal action against the trophozoites but also antibacterial activity against Gram-positive bacteria Staphylococcus aureus. The extract from leaves from shoot culture, already on the second and third days of treatment, showed an antiamoebicidal effect at a concentration of 1 mg mL-1 (inhibition of trophozoites 87.5% and 91.8%, respectively). In addition to leaves from shoot culture (a conc. 5 mg mL-1, 2nd day inhibition of trophozoites 85.7% and 3rd day 97.2%), leaves from a field-grown plant (a conc. 5 mg mL-1, 2nd day 91.0% and 3rd day 94.4%) and callus (a conc. 5 mg mL-1, 2nd day 90.0% and 3rd day – 95.4%) also exhibited a good antiamoebicidal activity. Out of the four extracts, the extracts from leaves from both shoot culture and a field-grown plant were reported to be the most active against Gram-positive S. aureus, which was determined by the values of MIC = 5.0 mg mL-1 and MIC = 2.5 mg mL-1, respectively. The inhibitory potential depends on the yield and composition of mainly bioactive compounds: pentacyclic terpenoids (mainly betulinic, ursolic, and oleanolic acids) and polyphenols (mainly chlorogenic acid and its isomers, epicatechin, dimeric, and trimeric proanthocyanidins, quercetin and kaempferol derivatives).