Instability of chromosome number and DNA methylation variation induced by hybridization and amphidiploid formation between Raphanus sativus L. and Brassica alboglabra Bailey

<p>Abstract</p> <p>Background</p> <p>Distant hybridization can result genome duplication and allopolyploid formation which may play a significant role in the origin and evolution of many plant species. It is unclear how the two or more divergent genomes coordinate in one nucleus with a single parental cytoplasm within allopolyploids. We used cytological and molecular methods to investigate the genetic and epigenetic instabilities associated with the process of distant hybridization and allopolyploid formation, measuring changes in chromosome number and DNA methylation across multiple generations.</p> <p>Results</p> <p>F₁plants from intergeneric hybridization between <it>Raphanus sativus </it>L. (2n = 18, RR) and <it>Brassica alboglabra </it>Bailey (2n = 18, CC) were obtained by hand crosses and subsequent embryo rescue. Random amplification of polymorphic DNA (RAPD) markers were used to identify the F₁hybrid plants. The RAPD data indicated that the hybrids produced specific bands similar to those of parents and new bands that were not present in either parent. Chromosome number variation of somatic cells from allotetraploids in the F₄to F₁₀generations showed that intensive genetic changes occurred in the early generations of distant hybridization, leading to the formation of mixopolyploids with different chromosome numbers. DNA methylation variation was revealed using MSAP (methylation-sensitive amplification polymorphism), which showed that cytosine methylation patterns changed markedly in the process of hybridization and amphidiploid formation. Differences in cytosine methylation levels demonstrated an epigenetic instability of the allopolyploid of <it>Raphanobrassica </it>between the genetically stable and unstable generations.</p> <p>Conclusions</p> <p>Our results showed that chromosome instability occurred in the early generations of allopolyploidy and then the plants were reverted to largely euploidy in later generations. During this process, DNA methylation changed markedly. These results suggest that, epigenetic mechanisms play an important role in intergeneric distant hybridization, probably by maintaining a genetic balance through the modification of existing genetic materials.</p

Facile synthesis of single atom electrocatalysts via a condensation-carbonization process

The general and cost-effective synthesis of single atom electrocatalysts (SAECs) still remains a great challenge. Herein, we report a general synthetic protocol for the synthesis of SAECs via a simple condensation-carbonization process, in which furfural and cyanamide were condensation polymerized in the presence of polystyrene nanospheres and metal ions, followed by a pyrolysis to N-doped carbon nanosheets (NCNSs) supported SAECs. Six types of SAECs containing platinum, palladium, gold, nickel, cobalt and iron were synthesized to demonstrate the generality of the synthesis protocol. This methodology affords a facile solution to the trade-off between support conductivity and metal loading of SAECs by optimizing the ratio of carbon/nitrogen precursors, i.e., furfural furfuryl and cyanamide. The presence of single metal atoms was confirmed by high-angle annular dark field scanning transmission electron microscopy and X-ray absorption fine structure measurements. The three-dimensional distribution of single platinum atoms was vividly revealed by depth profile analysis in the scanning transmission electron microscope. The resulting SAECs showed excellent performance for glycerol electro-oxidation and water splitting in alkaline solutions. Notably, Pt/NCNs possessed an unprecedent mass-normalized current density of 5.3 A per milligram of platinum, which is 32 times that of the commercial Pt/C catalyst. Density functional theory calculations were conducted to reveal the adsorption behavior of glycerol over the SAECs. Using Ni/NCNSs and Co/NCNSs as anodic and cathodic electrocatalysts, we constructed a solar panel powered electrolytic cell for overall water splitting, leading to an overall energy efficiency of 8.8%, which has been among one of the largest solar-to-hydrogen conversion efficiencies reported in the literature

Hemoglobin-derived Fe-Nx-S species supported by bamboo-shaped carbon nanotubes as efficient electrocatalysts for the oxygen evolution reaction

Herein, we report a facile route to synthesize isolated single iron atoms on nitrogen-sulfur-codoped carbon matrix via a direct pyrolysis process in which hemoglobin, a by-product of the meat industry, was utilized as a precursor for iron, nitrogen and sulfur while bamboo-shaped carbon nanotubes served as a support owing to their excellent conductivity and numerous defects. The resulting metal-nitrogen complexed carbon showed outstanding catalytic performance for the oxygen evolution reaction (OER) in alkaline solutions. At an overpotential of 380 mV, the optimal sample yielded a current density of 83.6 mA cm−2, which is 2.5 times that of benchmark IrO2 (32.8 mA cm−2), rendering it as one of the best OER catalysts reported so far. It also showed negligible activity decay in alkaline solutions during long-term durability tests. Control experiments and X-ray absorption fine structure analyses revealed that Fe-Nx species in the samples are the active sites for OER. Further density functional theory calculations indicated that the presence of sulfur in the carbon matrix modified the electronic structures of active species, thereby leading to the superior activity of the sample

Nonoscillatory solutions for first-order neutral dynamic equations with continuously distributed delay on time scales

Abstract In this paper, we establish the existence of nonoscillatory solutions to the neutral dynamic equation [x(t)−∫abp(t,η)x(g(t,η))Δη]Δ+∫cdω(t,ν)x(h(t,ν))Δν=0 $$\biggl[x(t)- \int_{a}^{b}p(t,\eta)x\bigl(g(t,\eta)\bigr)\Delta \eta \biggr]^{\Delta }+ \int_{c}^{d}\omega(t,\nu)x\bigl(h(t,\nu)\bigr)\Delta \nu=0$$ on a time scale T $\mathbb{T}$. Some examples are given to illustrate the main results

Effect Of Shen-Qi-Di-Huang Decoction On Reducing Proteinuria By Preseving Nephrin In Adriamycin-Induced Nephropathy Rats

The aim of this study is to investigate the effect of Shen-qi-di-huang decoction on reducing proteinuria and to discuss the mechanism of its action in Adriamycin (ADR)-induced nephropathy rats. The rats were randomly divided into three groups (n=12 each group): normal control (group A); ADR model control (group B); ADR + Shen-qi-di-huang decoction (group C). In group B and C, the rats were intravenously injected with ADR (6.5mg/kg). The rats in group C were orally administrated with Shen-qi-di-huang decoction after the injection of ADR. On day 7, 14, 28, 56 after ADR injection, 24h urine protein was detected. On day 28, 56 after ADR injection, ALB, ALT, serum creatinine (Scr) and BUN were examined. The morphological changes of the kidneys were observed by light microscope and electron microscope on day 28, 56 after ADR injection. The expression of nephrin was determined by immunohistochemistry and RT-PCR on day 28, 56 after ADR injection. Compared with group B, 24h urine protein and Scr decreased in group C on day 56 (P<0.05). The expression of nephrin determined by immunohistochemistry and RT-PCR increased in group C on day 28, 56 (P<0.05). The morphology observed by light microscope and electron microscope improved in group C on day 28, 56. Shen-qi-di-huang decoction decreases proteinuria, protects kidney function, and ameliorates histopathology in ADR-induced rats by preserving nephrin expression

Effect of Shen-Qi-Di-Huang Decoction on Reducing Proteinuria by Preserving Nephrin in Adriamycin-Induced Nephropathy Rats

The aim of this study is to investigate the effect of Shen-qi-di-huang decoction on reducing proteinuria and to discuss the mechanism of its action in Adriamycin (ADR)-induced nephropathy rats. The rats were randomly divided into three groups (n=12 each group): normal control (group A); ADR model control (group B); ADR + Shen-qi-di-huang decoction (group C). In group B and C, the rats were intravenously injected with ADR (6.5mg/kg). The rats in group C were orally administrated with Shen-qi-di-huang decoction after the injection of ADR. On day 7, 14, 28, 56 after ADR injection, 24h urine protein was detected. On day 28, 56 after ADR injection, ALB, ALT, serum creatinine (Scr) and BUN were examined. The morphological changes of the kidneys were observed by light microscope and electron microscope on day 28, 56 after ADR injection. The expression of nephrin was determined by immunohistochemistry and RT-PCR on day 28, 56 after ADR injection. Compared with group B, 24h urine protein and Scr decreased in group C on day 56 (P<0.05). The expression of nephrin determined by immunohistochemistry and RT-PCR increased in group C on day 28, 56 (P<0.05). The morphology observed by light microscope and electron microscope improved in group C on day 28, 56. Shen-qi-di-huang decoction decreases proteinuria, protects kidney function, and ameliorates histopathology in ADR-induced rats by preserving nephrin expression

Automatic handwritten mensural notation interpreter: From manuscript to MIDI performance

Huang Y.-H., Chen X., Beck S., Burn D., Van Gool L., ''Automatic handwritten mensural notation interpreter: From manuscript to MIDI performance'', 16th International Society for Music Information Retrieval conference - ISMIR 2015, pp. 79-85, October 26-30, 2015, Malaga, Spain. ISBN 987-84-606-8853-2status: publishe