The aim of the present study is to determine the influence of different concentrations of growth regulators on the hypocotyl explants regeneration abilities of flax cultivars (Linum usitatissimum L.). Plant material used in the study was obtained from two flax cultivars: Modran and Selena. Hypocotyl explants were obtained from 6-dayold seedlings and were subsequently placed on basal MS (Murashige and Skoog 1962) medium and MS medium supplemented with 6-benzylaminopurine (BAP) or naftalene acetic acid (NAA). Final evaluation of the callus, the shoot and the root formation of the explants was performed 28 days after the experimental setup. The highest regeneration effectiveness was observed on the media supplemented with 1 mg/l BAP.
Clubroot, caused by the protozoan parasite Plasmodiophora brassicae Woronin, is one of the most damaging diseases of Brassica napus worldwide. Resistant plant material is valuable for cultivation in all areas of high incidence of the disease and intensive growth of oilseed rape. We have evaluated clubroot resistance, plant morphology and seed quality in 15 lines of an F 4 generation and selected six lines of F 5 generation of interspecific hybrids obtained from a cross between a male sterile line of B. napus 'MS8', selected from resynthesized oilseed rape (B. rapa ssp. chinensis × B. oleracea var. gemmifera) and an ecotype of B. rapa ssp. pekinensis. Clubroot resistance was evaluated using a bioassay with P 1 -P 5 pathotypes of P. brassicae (according to the classification of Somé et al. 1996). The resistance to the pathotype P 1 was successfully fixed in the F 5 generation, and improved in some lines in respect to the pathotypes P 2 -P 4 . The resistance to P 1 and the other tested pathotypes was not linked. Characterization of plant material included recent techniques of FISH and BAC-FISH with a special focus on the analysis of ribosomal DNA (rDNA) of selected individuals. Two hybrid lines combined high levels of resistance with appropriate plant morphology, good seed quality traits and a stable chromosome number and arrangement. Recent techniques of 'chromosome painting' provided good insight into chromosome organization in the hybrids obtained, and offered opportunities of further improvement of the breeding process.
Median arcuate ligament syndrome (MALS) is a pathologic entity that can affect the celiac axis. Due to the extensive collateral network of mesenteric circulation, stenosis of one mesenteric artery does not lead to significant symptoms. The purpose of this study was to describe multidetector computed tomography (MDCT) angiography findings of celiac artery entrapment by the median arcuate ligament and determine those patients with high risks of ischemic complications. From January 2012 to March 2016, 103 patients with celiac artery (CA) compression by median arcuate ligament were detected. In 23 patients collateral circulation was developed. In order to investigate the problem, we managed to estimate the correlation between range of stenosis of CA and presence of collateral circulation between the celiac artery (CA) and superior mesenteric artery (SMA). A statistically significant correlation was found between range of CA stenosis and collateral circulation presence (Spearman's correlation coefficient 0.339, P < 0.0001). In conclusions, based on our observations, we hypothesize that ischemia as a result of mesenteric vessel narrowing by the median arcuate ligament may occur more often than indicated by clinical symptoms and described in literature. Clin. Anat. 29:1025-1030, 2016. © 2016 Wiley Periodicals, Inc.
The study includes the results of research conducted on selected lead-free binary solder alloys designed for operation at high temperatures. The results of qualitative and quantitative metallographic examinations of SnZn alloys with various Zn content are presented. The quantitative microstructure analysis was carried out using a combinatorial method based on phase quanta theory, per which any microstructure can be treated as an array of elements disposed in the matrix material. Fatigue tests were also performed using the capabilities of a modified version of the LCF method hereinafter referred to in short as MLCF, which is particularly useful in the estimation of mechanical parameters when there are difficulties in obtaining many samples normally required for the LCF test. The fatigue life of alloys was analyzed in the context of their microstructure. It has been shown that the mechanical properties are improved with the Zn content increasing in the alloy. However, the best properties were obtained in the alloy with a chemical composition close to the eutectic system, when the Zn-rich precipitates showed the most preferred morphological characteristics. At higher content of Zn, a strong structural notch was formed in the alloy because of the formation in the microstructure of a large amount of the needle-like Zn-rich precipitates deteriorating the mechanical characteristics. Thus, the results obtained during previous own studies, which in the field of mechanical testing were based on static tensile test only, have been confirmed. It is interesting to note that during fatigue testing, both significant strengthening and weakening of the examined material can be expected. The results of fatigue tests performed on SnZn alloys have proved that in this case the material was softened.
Interspecific hybridization is an important tool to transfer characters across species and develop synthetic amphidiploids, and therefore it has been widely applied for improving Brassica spp. The aim of our study was to determine whether the interspecific crosses can help increase the range of variability of traits connected with the higher value of rapeseed. An attempt was also made to investigate the environmental influence on the studied traits. For this reason, in our experiments, crosses between male sterile line of F8 generation and B. campestris ssp. sarson, Yellow sarson; B. campestris ssp. pekinensis; B. carinata and B. juncea were first attempted. Thereafter, hybrid seeds of 96 lines obtained by crossing Brassica napus male sterile line MS8 with three other Brassica species were tested for fiber and glucosinolates content using near-infrared reflectance spectroscopy (NIRS). Moreover, chromatography and spectrophotometric measurements of sinapine and tocopherols contents in those seeds were made. On the basis of the obtained results, it was found that all tested hybrid lines showed a great increase of variability for the studied quality traits when compared to the parental forms. As a result of our analyses, reduced glucosinolates hybrid lines were selected.
In oxidizing environments, most tin-based lead (Pb)-free alloys form a tin oxide that is easily eroded or mechanically damaged, affecting corrosion resistance and thus reliability of the soldered joints. In this study, the effect of microstructure heterogeneity on corrosion behavior of Pb-free solder candidate systems has been investigated on the example of as-cast and heat-treated alloys. The research was focused on a comparison between the corrosion resistance of binary Sn-Zn and ternary Sn-Zn-Cu alloys. Accelerated corrosion tests were performed by means of electrochemical methods in the sodium sulfate solution (VI), Na 2 SO 4 , of about 0.5 M concentration, pH adjusted to 2 by means of concentrated H 2 SO 4 acid. In these tests, the corrosion potentials as well as polarization curves were determined for the selected alloys in as-cast state and after their heat treatment using different combinations of processing parameters. The measurements of basic electrochemical characteristics were made, i.e., the corrosion current (i corr lA/cm 2 ) and Tafel coefficients, both cathodic (b c V/dec) and anodic (b a V/dec) ones. Detailed structural characterization of as-cast and heat-treated alloys before and after accelerated corrosion tests has been made under a wide range of magnifications using light microscopy and scanning electron microscopy observations. The results showed that structural heterogeneity of the examined alloys, attributed to the presence of secondary phases, and affected by their size and distribution, significantly influences the behavior of the examined Pb-free Sn-Zn-based alloys in the corrosive environment.
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