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101.
E. M. Sara Moreno Pablo R. Speranza Juan M. Roggero Luque Viviana G. Solís Neffa 《Plant Systematics and Evolution》2015,301(3):883-892
Turnera sidoides is a complex of outcrossing, perennial, rhizomatous herbs that is widely distributed in southern South America. Five subspecies are recognized taxonomically based on morphological features and geographical distribution. In certain regions, the areas of distribution of the subspecies overlap partially. In such contact zones, the extent of reproductive barriers among subspecies is still largely unknown, but morphologically intermediate individuals have been found in the field, indicating that hybridization may actually occur between subspecies. Crossability among subspecies of T. sidoides has been shown by experimental studies with cultivated plants, but the mechanisms involved in natural populations are still unknown. To investigate the mechanisms that underlie gene flow within the T. sidoides complex, in this paper we analyze the morphological and genetic variation, as well as the crossability among taxa in a contact zone between subspecies pinnatifida and sidoides, in southeastern Uruguay. Our results constitute the first evidences of ongoing natural hybridization between subspecies of T. sidoides and suggest that, although hybridization may not have been of significance in the early phase of the species differentiation, reticulate evolution is ongoing enhancing the current morphological and genetic variability of the complex. 相似文献
102.
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104.
Pérez D Crespo M Solé L Prat M Carcasona C Calama E Otal R Gavaldá A Gómez-Angelats M Miralpeix M Puig C 《Bioorganic & medicinal chemistry letters》2011,21(5):1545-1548
The synthesis of diverse functionalized ureas in a semi-parallel fashion is described, as well as their β1/β2-adrenergic activities and the corresponding structure-activity relationship (SAR). We have focused on lipophilicity and duration of action, and we have discovered a strong correlation in this series of molecules. A quantitative structure-activity relationship (QSAR) analysis will be presented that quantifies this relationship. 相似文献
105.
Riley KE Murray JS Fanfrlík J Rezáč J Solá RJ Concha MC Ramos FM Politzer P 《Journal of molecular modeling》2011,17(12):3309-3318
In the past several years, halogen bonds have been shown to be relevant in crystal engineering and biomedical applications.
One of the reasons for the utility of these types of noncovalent interactions in the development of, for example, pharmaceutical
ligands is that their strengths and geometric properties are very tunable. That is, substitution of atoms or chemical groups
in the vicinity of a halogen can have a very strong effect on the strength of the halogen bond. In this study we investigate
halogen-bonding interactions involving aromatically-bound halogens (Cl, Br, and I) and a carbonyl oxygen. The properties of
these halogen bonds are modulated by substitution of aromatic hydrogens with fluorines, which are very electronegative. It
is found that these types of substitutions have dramatic effects on the strengths of the halogen bonds, leading to interactions
that can be up to 100% stronger. Very good correlations are obtained between the interaction energies and the magnitudes of
the positive electrostatic potentials (σ-holes) on the halogens. Interestingly, it is seen that the substitution of fluorines
in systems containing smaller halogens results in electrostatic potentials resembling those of systems with larger halogens,
with correspondingly stronger interaction energies. It is also shown that aromatic fluorine substitutions affect the optimal
geometries of the halogen-bonded complexes, often as the result of secondary interactions. 相似文献
106.
Jin H Cantin GT Maki S Chew LC Resnick SM Ngai J Retallack DM 《Protein expression and purification》2011,78(1):69-77
Cost-effective production of soluble recombinant protein in a bacterial system remains problematic with respect to expression levels and quality of the expressed target protein. These constraints have particular meaning today as "biosimilar" versions of innovator protein drugs are entering the clinic and the marketplace. A high throughput, parallel processing approach to expression strain engineering was used to evaluate soluble expression of human granulocyte colony-stimulating factor (G-CSF) in Pseudomonas fluorescens. The human g-csf gene was optimized for expression in P. fluorescens and cloned into a set of periplasmic expression vectors. These plasmids were transformed into a variety of P. fluorescens host strains each having a unique phenotype, to evaluate soluble expression in a 96-well growth and protein expression format. To identify a strain producing high levels of intact, soluble Met-G-CSF product, more than 150 protease defective host strains from the Pfēnex Expression Technology? toolbox were screened in parallel using biolayer interferometry (BLI) to quantify active G-CSF binding to its receptor. A subset of these strains was screened by LC-MS analysis to assess the quality of the expressed G-CSF protein. A single strain with an antibiotic resistance marker insertion in the pfaI gene was identified that produced>99% Met-GCSF. A host with a complete deletion of the autotransporter-coding gene pfaI from the genome was constructed, and expression of soluble, active Met-GSCF in this strain was observed to be 350mg/L at the 1 liter fermentation scale. 相似文献
107.
Taminau J Steenhoff D Coletta A Meganck S Lazar C de Schaetzen V Duque R Molter C Bersini H Nowé A Weiss Solís DY 《Bioinformatics (Oxford, England)》2011,27(22):3204-3205
Microarray technology has become an integral part of biomedical research and increasing amounts of datasets become available through public repositories. However, re-use of these datasets is severely hindered by unstructured, missing or incorrect biological samples information; as well as the wide variety of preprocessing methods in use. The inSilicoDb R/Bioconductor package is a command-line front-end to the InSilico DB, a web-based database currently containing 86 104 expert-curated human Affymetrix expression profiles compiled from 1937 GEO repository series. The use of this package builds on the Bioconductor project's focus on reproducibility by enabling a clear workflow in which not only analysis, but also the retrieval of verified data is supported. 相似文献
108.
Bae JS Cheong HS Kim JH Park BL Kim JH Park TJ Kim JY Pasaje CF Lee JS Park YJ Park M Park C Koh I Chung YJ Lee JY Shin HD 《PloS one》2011,6(4):e19091
Background
Unlike Caucasian populations, genetic factors contributing to the risk of type 2 diabetes mellitus (T2DM) are not well studied in Asian populations. In light of this, and the fact that copy number variation (CNV) is emerging as a new way to understand human genomic variation, the objective of this study was to identify type 2 diabetes–associated CNV in a Korean cohort.Methodology/Principal Findings
Using the Illumina HumanHap300 BeadChip (317,503 markers), genome-wide genotyping was performed to obtain signal and allelic intensities from 275 patients with type 2 diabetes mellitus (T2DM) and 496 nondiabetic subjects (Total n = 771). To increase the sensitivity of CNV identification, we incorporated multiple factors using PennCNV, a program that is based on the hidden Markov model (HMM). To assess the genetic effect of CNV on T2DM, a multivariate logistic regression model controlling for age and gender was used. We identified a total of 7,478 CNVs (average of 9.7 CNVs per individual) and 2,554 CNV regions (CNVRs; 164 common CNVRs for frequency>1%) in this study. Although we failed to demonstrate robust associations between CNVs and the risk of T2DM, our results revealed a putative association between several CNVRs including chr15:45994758–45999227 (P = 8.6E-04, Pcorr = 0.01) and the risk of T2DM. The identified CNVs in this study were validated using overlapping analysis with the Database of Genomic Variants (DGV; 71.7% overlap), and quantitative PCR (qPCR). The identified variations, which encompassed functional genes, were significantly enriched in the cellular part, in the membrane-bound organelle, in the development process, in cell communication, in signal transduction, and in biological regulation.Conclusion/Significance
We expect that the methods and findings in this study will contribute in particular to genome studies of Asian populations. 相似文献109.
Gurevitz JM Ceballos LA Gaspe MS Alvarado-Otegui JA Enríquez GF Kitron U Gürtler RE 《PLoS neglected tropical diseases》2011,5(10):e1349
Background
Transmission of Trypanosoma cruzi by Triatoma infestans remains a major public health problem in the Gran Chaco ecoregion, where understanding of the determinants of house infestation is limited. We conducted a cross-sectional study to model factors affecting bug presence and abundance at sites within house compounds in a well-defined rural area in the humid Argentine Chaco.Methodology/Principal Findings
Triatoma infestans bugs were found in 45.9% of 327 inhabited house compounds but only in 7.4% of the 2,584 sites inspected systematically on these compounds, even though the last insecticide spraying campaign was conducted 12 years before. Infested sites were significantly aggregated at distances of 0.8–2.5 km. The most frequently infested ecotopes were domiciles, kitchens, storerooms, chicken coops and nests; corrals were rarely infested. Domiciles with mud walls and roofs of thatch or corrugated tarred cardboard were more often infested (32.2%) than domiciles with brick-and-cement walls and corrugated metal-sheet roofs (15.1%). A multi-model inference approach using Akaike''s information criterion was applied to assess the relative importance of each variable by running all possible (17,406) models resulting from all combinations of variables. Availability of refuges for bugs, construction with tarred cardboard, and host abundance (humans, dogs, cats, and poultry) per site were positively associated with infestation and abundance, whereas reported insecticide use showed a negative association. Ethnic background (Creole or Toba) adjusted for other factors showed little or no association.Conclusions/Significance
Promotion and effective implementation of housing improvement (including key peridomestic structures) combined with appropriate insecticide use and host management practices are needed to eliminate infestations. Fewer refuges are likely to result in fewer residual foci after insecticide spraying, and will facilitate community-based vector surveillance. A more integrated perspective that considers simultaneously social, economic and biological processes at local and regional scales is needed to attain effective, sustainable vector and disease control. 相似文献110.
The addition of glucose or other sugars to resting cells of Serratia maurcescens induced rapid acidification of the extracellular medium. This acidification was due to the catabolism of sugars. The rate of acidification depended on the carbon source and its concentration. HPLC analysis of the supernatants demonstrated that the progressive fall in pH resulted from the rapid production of lactic, acetic, pyruvic and citric acids. Other microorganisms were tested for their ability to produce this rapid acidification of the medium. This study may provide a rapid and simple method for metabolism studies. 相似文献