51 research outputs found
(1R,3S)-Methyl 3-[(S)-2-(hydroxyÂdiphenylÂmethÂyl)pyrrolidin-1-ylmethÂyl]-2,2-dimethylÂcycloÂpropaneÂcarboxylÂate
The asymmetric unit of the title compound, C25H31NO3, prepared from (â)-1R-cis-caronaldehyde, contains three independent molÂecules with similar conformations. The hydrÂoxy groups are involved in intraÂmolecular OâHâŻN hydrogen bonds. The crystal packing exhibits weak interÂmolecular OâHâŻO and CâHâŻO hydrogen bonds
Nucleotide differences in the mbf1 gene of the lichenized fungus Umbilicaria decussata collected in polar and non-polar regions
Multiprotein bridging factor 1 (MBF1) is a transcriptional co-activator related to stress tolerance in various organisms. We investigated the nucleotide differences in the mbf1 gene in the lichen-forming fungus Umbilicaria decussata collected from polar (i.e., Antarctica and the Arctic) and non-polar (i.e., Armenia) regions. The 552-bp Udmbf1 genes isolated from eight samples contained numerous sequence variations, including single nucleotide polymorphisms as well as insertions and deletions. The frequency of nucleotide changes was higher in the intron than in the coding sequence. The nucleotide polymorphism levels (Ď=0.01792, θ=0.01792) and haplotype diversity (Hd=1) in the Udmbf1 gene from Antarctic samples were relatively high. Additionally, of the 19 detected nucleotide sequence variation sites, 15 were observed only in Antarctic samples. The resulting amino acid changes occurred in the N-terminal, whose function remains unknown. Although these DNA polymorphisms and amino acid changes have been verified in Antarctic samples of U. decussata, there is still little evidence indicating that different environmental conditions affected the functional evolution of Udmbf1. Additional studies involving more U. decussata samples from representative ecotypes will be necessary to uncover the relationships among DNA polymorphisms, functional gene evolution, and lichen habitats
Phosphine-Catalyzed Annulations of Azomethine Imines: Allene-Dependent [3 + 2], [3 + 3], [4 + 3], and [3 + 2 + 3] Pathways
In this paper we describe the phosphine-catalyzed [3 + 2], [3 + 3], [4 + 3], and [3 + 2 + 3] annulations of azomethine imines and allenoates. These processes mark the first use of azomethine imines in nucleophilic phosphine catalysis, producing dinitrogen-fused heterocycles, including tetrahydropyrazolo-pyrazolones, -pyridazinones, -diazepinones, and -diazocinones. Counting the two different reaction modes in the [3 + 3] cyclizations, there are five distinct reaction pathwaysâthe choice of which depends on the structure and chemical properties of the allenoate. All reactions are operationally simple and proceed smoothly under mild reaction conditions, affording a broad range of 1,2-dinitrogen-containing heterocycles in moderate to excellent yields. A zwitterionic intermediate formed from a phosphine and two molecules of ethyl 2,3-butadienoate acted as a 1,5-dipole in the annulations of azomethine imines, leading to the [3 + 2 + 3] tetrahydropyrazolo-diazocinone products. The incorporation of two molecules of an allenoate into an eight-membered-ring product represents a new application of this versatile class of molecules in nucleophilic phosphine catalysis. The salient features of this protocolâthe facile access to a diverse range of nitrogen-containing heterocycles and the simple preparation of azomethine imine substratesâsuggest that it might find extensive applications in heterocycle synthesis
Liverome: a curated database of liver cancer-related gene signatures with self-contained context information
<p>Abstract</p> <p>Background</p> <p>Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide. A number of molecular profiling studies have investigated the changes in gene and protein expression that are associated with various clinicopathological characteristics of HCC and generated a wealth of scattered information, usually in the form of gene signature tables. A database of the published HCC gene signatures would be useful to liver cancer researchers seeking to retrieve existing differential expression information on a candidate gene and to make comparisons between signatures for prioritization of common genes. A challenge in constructing such database is that a direct import of the signatures as appeared in articles would lead to a loss or ambiguity of their context information that is essential for a correct biological interpretation of a geneâs expression change. This challenge arises because designation of compared sample groups is most often abbreviated, <it>ad hoc</it>, or even missing from published signature tables. Without manual curation, the context information becomes lost, leading to uninformative database contents. Although several databases of gene signatures are available, none of them contains informative form of signatures nor shows comprehensive coverage on liver cancer. Thus we constructed Liverome, a curated database of liver cancer-related gene signatures with self-contained context information.</p> <p>Description</p> <p>Liveromeâs data coverage is more than three times larger than any other signature database, consisting of 143 signatures taken from 98 HCC studies, mostly microarray and proteome, and involving 6,927 genes. The signatures were post-processed into an informative and uniform representation and annotated with an itemized summary so that all context information is unambiguously self-contained within the database. The signatures were further informatively named and meaningfully organized according to ten functional categories for guided browsing. Its web interface enables a straightforward retrieval of known differential expression information on a query gene and a comparison of signatures to prioritize common genes. The utility of Liverome-collected data is shown by case studies in which useful biological insights on HCC are produced.</p> <p>Conclusion</p> <p>Liverome database provides a comprehensive collection of well-curated HCC gene signatures and straightforward interfaces for gene search and signature comparison as well. Liverome is available at <url>http://liverome.kobic.re.kr</url>.</p
Structural and physicochemical effects on the starch quality of the high-quality wheat genotype caused by delayed sowing
BackgroundBread wheat is one of the most important food crops associated with ensuring food security and human nutritional health. The starch quality is an important index of high-quality wheat. It is affected by a complex series of factors; among which, suitable sowing time is a key factor.Aim and methodsTo analyze the integrative effects of sowing time on the starch quality of high-quality wheat, in the present study, we selected a high-quality bread wheat cultivar Jinan 17 and investigated the effect of different sowing times on the starch properties and the related genes by analyzing X-ray diffraction patterns, apparent amylose content, thermal properties, pasting properties, in vitro starch digestibility, and qRT-PCR. Meanwhile, we also investigated the agronomic and yield performance that may be associated with the starch properties.ResultsDelayed sowing had little effect on starch crystalline morphology, but there was a tendency to reduce the formation of crystals within wheat starch granules: (1) delayed sowing for 15âdays altered the thermal properties of starch, including onset, peak and termination temperatures, and enthalpy changes; (2) delayed sowing for 30âdays changed the thermal characteristics of starch relatively insignificant; (3) significant differences in pasting characteristics occurred: peak viscosity and hold-through viscosity increased, while final viscosity, breakdown viscosity, and setback viscosity tended to increase and then decrease, suggesting that delayed sowing caused changes in the surface of the starch granules resulting in a decrease in digestibility. Analysis of related genes showed that several key enzymes in starch biosynthesis were significantly affected by delayed sowing, leading to a reduction in apparent straight-chain starch content. In addition to starch properties, thousand-kernel weight also increased under delayed sowing conditions compared with normal sowing.ConclusionThe impact of delayed sowing on starch quality is multifaceted and complex, from the fine structure, and functional properties of the starch to the regulation of key gene expression. Our study holds significant practical value for optimizing wheat planting management and maximizing the potential in both quality and yield
Bulked segregant RNA-seq reveals complex resistance expression profile to powdery mildew in wild emmer wheat W762
Powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is one of the most destructive fungal diseases threatening global wheat production. Exploring powdery mildew resistance (Pm) gene(s) and dissecting the molecular mechanism of the host resistance are critical to effectively and reasonably control this disease. Durum wheat (Triticum turgidum L. var. durumDesf.) is an important gene donor for wheat improvement against powdery mildew. In this study, a resistant durum wheat accession W762 was used to investigate its potential resistance component(s) and profile its expression pattern in responding to Bgt invasion using bulked segregant RNA-Seq (BSR-Seq) and further qRT-PCR verification. Genetic analysis showed that the powdery mildew resistance in W762 did not meet monogenic inheritance and complex genetic model might exist within the population of W762 Ă Langdon (susceptible durum wheat). After BSR-Seq, 6,196 consistently different single nucleotide polymorphisms (SNPs) were called between resistant and susceptible parents and bulks, and among them, 763 SNPs were assigned to the chromosome arm 7B. Subsequently, 3,653 differentially expressed genes (DEGs) between resistant and susceptible parents and bulks were annotated and analyzed by Gene Ontology (GO), Cluster of Orthologous Groups (COG), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment. The potential regulated genes were selected and analyzed their temporal expression patterns following Bgt inoculation. As a result, nine disease-related genes showed distinctive expression profile after Bgt invasion and might serve as potential targets to regulate the resistance against powdery mildew in W762. Our study could lay a foundation for analysis of the molecular mechanism and also provide potential targets for the improvement of durable resistance against powdery mildew
Optimization for the Production of Surfactin with a New Synergistic Antifungal Activity
-surfactin and the optimization of its production by the response surface method.O. A production of 134.2 mg/L, which were in agreement with the prediction, was observed in a verification experiment. In comparison to the production of original level (88.6 mg/L), a 1.52-fold increase had been obtained.-surfactin
Dominância fiscal : uma investigação empĂrica sobre o caso brasileiro no perĂodo de 2003 a 2014
A estabilização econômica dos anos de 1990 e a adoção do tripÊ econômico, a partir de
1999, marcam o fim de um capĂtulo delicado da histĂłria brasileira; a partir de entĂŁo, era
necessĂĄria a existĂŞncia de certa sintonia de polĂticas monetĂĄria e fiscal para a
manutenção do controle dos diversos indicadores econômicos. Contudo, com essa
reciprocidade na polĂtica econĂ´mica, sĂŁo incitadas discussĂľes sobre a orientação do
governo na hora de definir suas prioridades nesse campo: as variĂĄveis fiscais sĂŁo
priorizadas e, por conseguinte, determinadas, forçando as monetĂĄrias a se ajustarem â
ou o contrĂĄrio? A resposta para esse questionamento leva Ă discussĂŁo sobre a
dominância fiscal. Assim, esse trabalho visa verificar empiricamente, usando das
modelagens economÊtricas VAR e estudo de eventos, se hå dominância fiscal ou
monetĂĄria na economia brasileira e se a eficĂĄcia da polĂtica monetĂĄria mudou na
transição do governo Lula para o governo Dilma. O resultado foi inconclusivo para o
governo Lula e indicou dominância fiscal no governo Dilma. Ainda verificou-se não
haver modificação na eficĂĄcia da polĂtica monetĂĄria.Economic stabilization, in the 1990s, and utilization of an economic tripod, after 1999,
represents the end of a delicate chapter in Brazilian history. Ever since, it was necessary
the existence of a certain agreement between monetary and fiscal politic, in order to
maintain under control a variety of economic indicators. However, this reciprocity (in
economic politic) starts discussions about the real government orientations when it
comes to define its priority on this subject: are the fiscal variables priorized, and then,
determined, forcing monetary variables to adjust themselves, or the opposite? The
answer to these questions emerge from the fiscal dominance discussion. This paper
intends to empiric verify, using econometric modeling VAR and event study, if there is
fiscal dominance or monetary in Brazilian economy and whether the effectiveness of
monetary politic has changed in the transition from Lula's government to the Dilma
government. The result was inconclusive for the Lula government and indicated fiscal
dominance in the Dilma government. There was still no change in the efficiency of the
monetary politic.CAPE
Cooperative Ants Approach for a 2D Navigational Map of 3D virtual Scene
Abstract. The problem of intelligent agent navigation in virtual environment is the subject of many recent AI researches. Although many solutions have been proposed for these, the ever-growing complexity of virtual environments inhabited by sophisticated characters makes it necessary to further elaborate computational models used for building such a navigational map. In this paper we propose a cooperative ants approach for this problem. The novel idea of our approach is the implicit collaboration way, which free us from the complex communication among avatars in a Distributed Virtual Environment (DVE) system. There are some collision exactly, but our approach makes it least and keeps system high efficient.
Isolation and characterization of a new iturinic lipopeptide, mojavensin A produced by a marine-derived bacterium Bacillus mojavensis B0621A
Three lipopeptides were isolated by bioactivity-guided fractionation from the fermentation broth of Bacillus mojavensis B0621A. A new iturinic lipopeptide, named mojavensin A, was tentatively characterized by 1D, 2D NMR and MS spectroscopy, Marfey's method containing a novel peptide backbone of L-Asn(1), D-Tyr(2), D-Asn(3), L-Gln(4), L-Pro(5), D-Asn(6), L-Asn(7) and an anteiso-type of the saturated beta-fatty acid side chain. Compound 2 and 3 were tentatively identified as iso-C16 fengycin B and anteiso-C17 fengycin B, respectively. These lipopeptides displayed dose-dependent antifungal activity against a broad spectra of phytopathogens and were weakly antagonistic to Staphylococcus aureus. Moreover, they all revealed cytotoxic activities against the human leukemia (HL-60) cell line. Mojavensin A, iso-C16 fengycin B, and anteiso-C17 fengycin B inhibited the growth of HL-60 with IC(5)(0) of 100, 100 and 1.6 muM, respectively
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