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https://www.readbyqxmd.com/read/29783186/-1-h-nmr-and-uplc-ms-metabolomics-functional-tools-for-exploring-chemotypic-variation-in-sceletium-tortuosum-from-two-provinces-in-south-africa
#1
Jianping Zhao, Ikhlas A Khan, Sandra Combrinck, Maxleene Sandasi, Weiyang Chen, Alvaro M Viljoen
Sceletium tortuosum (Aizoaceae) is widely recognised for the treatment of stress, anxiety and depression, as well as for obsessive compulsive disorders. A comprehensive intraspecies chemotypic variation study, using samples harvested from two distinct regions of South Africa, was done using both proton nuclear magnetic resonance (1 H-NMR) spectroscopy of methanol extracts (N = 145) and ultra performance liquid chromatography-mass spectrometry (UPLC-MS) of acid/base extracts (N = 289). Chemometric analysis of the 1 H-NMR data indicated two main clusters that were region-specific (Northern Cape and Western Cape provinces)...
May 17, 2018: Phytochemistry
https://www.readbyqxmd.com/read/29783110/temporal-and-spatial-variation-in-the-mechanisms-used-by-microorganisms-to-form-methylmercury-in-the-water-column-of-changshou-lake
#2
Zhilin Xing, Tiantao Zhao, Weiyang Bai, Xu Yang, Shuai Liu, Lijie Zhang
The microbiome in artificial lake water and its impact on mercury (Hg) methylation remain largely unknown. We selected the largest artificial lake in southeastern china, Changshou Lake (CSL), which has high background levels of Hg, for our investigation of Hg transformation microorganisms. Five different sections of the water column of CSL were sampled during four seasons. The water samples were subjected to analysis of geochemical parameters, various Hg species and microbiome information. High concentrations of total mercury (THg) were detected in CSL in comparison with those found in natural lakes...
May 18, 2018: Ecotoxicology and Environmental Safety
https://www.readbyqxmd.com/read/29782994/structural-covariance-of-brain-region-volumes-is-associated-with-both-structural-connectivity-and-transcriptomic-similarity
#3
Yohan Yee, Darren J Fernandes, Leon French, Jacob Ellegood, Lindsay S Cahill, Dulcie A Vousden, Leigh Spencer Noakes, Jan Scholz, Matthijs C van Eede, Brian J Nieman, John G Sled, Jason P Lerch
An organizational pattern seen in the brain, termed structural covariance, is the statistical association of pairs of brain regions in their anatomical properties. These associations, measured across a population as covariances or correlations usually in cortical thickness or volume, are thought to reflect genetic and environmental underpinnings. Here, we examine the biological basis of structural volume covariance in the mouse brain. We first examined large scale associations between brain region volumes using an atlas-based approach that parcellated the entire mouse brain into 318 regions over which correlations in volume were assessed, for volumes obtained from 153 mouse brain images via high-resolution MRI...
May 18, 2018: NeuroImage
https://www.readbyqxmd.com/read/29782917/detoxification-and-immunoprotection-of-zn-ii-curcumin-in-juvenile-pacific-white-shrimp-litopenaeus-vannamei-feed-with-aflatoxin-b1
#4
Ying-Ying Yu, Jin Niu, Pen Yin, Yong-Jian Liu, Li-Xia Tian, Donghui Xu
Aflatoxins, which was produced by Aspergillus flavus or Aspergillus parasiticus fungi during grain and feed processing or storage, could cause severe health problems and reduction of yield during shrimp cultures. To evaluate toxic effects of aflatoxin B1 (AFB1) in juvenile Pacific white shrimp (Litopenaeus vannamei) and potential protective effect of Zn(II)-curcumin (Zn-CM), four experimental diets (control, 500 μg/kg AFB1, 500 μg/kg AFB1+100 mg/kg Zn-CM, 500 μg/kg AFB1+200 mg/kg Zn-CM) were formulated in quadruplicate to feed the shrimp for 8 weeks...
May 18, 2018: Fish & Shellfish Immunology
https://www.readbyqxmd.com/read/29782705/wild-gwas-association-mapping-in-natural-populations
#5
Anna W Santure, Dany Garant
The increasing affordability of sequencing and genotyping technologies has transformed the field of molecular ecology in recent decades. By correlating marker variants with trait variation using association analysis, large-scale genotyping and phenotyping of individuals from wild populations has enabled the identification of genomic regions that contribute to phenotypic differences among individuals. Such 'gene mapping' studies are enabling us to better predict evolutionary potential and the ability of populations to adapt to challenges, such as changing environment...
May 21, 2018: Molecular Ecology Resources
https://www.readbyqxmd.com/read/29782655/cross-scale-occupancy-dynamics-of-a-post-fire-specialist-in-response-to-variation-across-a-fire-regime
#6
Morgan W Tingley, Andrew N Stillman, Robert L Wilkerson, Christine A Howell, Sarah C Sawyer, Rodney B Siegel
1.Fire creates challenges and opportunities for wildlife through rapid destruction, modification, and creation of habitat. Fire has spatially variable effects on landscapes, however, and for species that benefit from the ephemeral resource patches created by fire, it is critical to understand characteristics of fires that promote post-fire colonization and persistence, and the spatial scales on which they operate. 2.Using a model post-fire specialist, the black-backed woodpecker (Picoides arcticus), we examined how colonization and persistence varied across two spatial scales as a function of four characteristics of fire regimes - fire severity, fire size, fire ignition date, and number of years since fire...
May 21, 2018: Journal of Animal Ecology
https://www.readbyqxmd.com/read/29782644/on-the-relationship-between-phylogenetic-diversity-and-trait-diversity
#7
Caroline M Tucker, T Jonathan Davies, Marc W Cadotte, William D Pearse
Niche differences are key to understanding the distribution and structure of biodiversity. To examine niche differences, we must first characterize how species occupy niche space, and two approaches are commonly used in the ecological literature. The first uses species traits to estimate multivariate trait space (so-called functional trait diversity, FD); the second quantifies the amount of time or evolutionary history captured by a group of species (phylogenetic diversity, PD). It is often-but controversially-assumed that these putative measures of niche space are at a minimum correlated and perhaps redundant, since more evolutionary time allows for greater accumulation of trait changes...
May 21, 2018: Ecology
https://www.readbyqxmd.com/read/29782530/histone-methylation-changes-are-required-for-life-cycle-progression-in-the-human-parasite-schistosoma-mansoni
#8
David Roquis, Aaron Taudt, Kathrin K Geyer, Gilda Padalino, Karl F Hoffmann, Nancy Holroyd, Matt Berriman, Benoît Aliaga, Cristian Chaparro, Christoph Grunau, Ronaldo de Carvalho Augusto
Epigenetic mechanisms and chromatin structure play an important role in development. Their impact is therefore expected to be strong in parasites with complex life cycles and multiple, strikingly different, developmental stages, i.e. developmental plasticity. Some studies have already described how the chromatin structure, through histone modifications, varies from a developmental stage to another in a few unicellular parasites. However, this, to our knowledge, has never been done before in multicellular metazoan parasites...
May 21, 2018: PLoS Pathogens
https://www.readbyqxmd.com/read/29782172/assembly-dynamics-of-plasmonic-dna-capped-gold-nanoparticle-monolayers
#9
Thomas L Derrien, Michelle Zhang, Patrick Dorion, Detlef-M Smilgies, Dan Luo
The self-assembly of nanoparticles in aqueous solutions promises wide applications but requires the careful balance of many parameters not present in organic solvents. While the presence of long-range electrostatic interactions in aqueous solutions may complicate such assemblies, they provide additional parameters through which to control self-assembly. Here, with DNA-capped gold nanoparticles and through variation of the ionic strength in aqueous solutions, we explored the influence of electrostatic interactions on the adsorption of negatively charged nanoparticles on a positively charged surface...
May 21, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/29781997/antimicrobial-peptides-produced-by-selective-pressure-incorporation-of-non-canonical-amino-acids
#10
Jessica H Nickling, Tobias Baumann, Franz-Josef Schmitt, Maike Bartholomae, Oscar P Kuipers, Thomas Friedrich, Nediljko Budisa
Nature has a variety of possibilities to create new protein functions by modifying the sequence of the individual amino acid building blocks. However, all variations are based on the 20 canonical amino acids (cAAs). As a way to introduce additional physicochemical properties into polypeptides, the incorporation of non-canonical amino acids (ncAAs) is increasingly used in protein engineering. Due to their relatively short length, the modification of ribosomally synthesized and post-translationally modified peptides by ncAAs is particularly attractive...
May 4, 2018: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/29781492/single-electron-transport-through-stabilised-silicon-nanocrystals
#11
Tuhin Shuvra Basu, Simon Diesch, Elke Scheer
We have fabricated organically capped stable luminescent silicon nanocrystals with narrow size distribution by a novel, high yield and easy to implement technique. We demonstrate transport measurements of individual silicon nanocrystals by scanning tunnelling microscopy at a low temperature in a double-barrier tunnel junction arrangement in which we observed pronounced single electron tunnelling effects. The tunnelling spectroscopy of these nanocrystals with different diameters reveals quantum confinement induced bandgap modifications...
May 21, 2018: Nanoscale
https://www.readbyqxmd.com/read/29781446/pyro-phototronic-nanogenerator-based-on-flexible-2d-zno-graphene-heterojunction-and-its-application-in-self-powered-near-infrared-photodetector-and-active-analog-frequency-modulation
#12
Parikshit Sahatiya, Akash Shinde, Sushmee Badhulika
Even though 2D ZnO has been utilized for enhanced self-powered sensing by strain modulation due to its piezoelectric property, study on utilizing pyroelectric property of ZnO remains unexplored. The piezoelectric property of 2D ZnO works on mechanical strain which disrupts the structure of ZnO leading to the failure of device. For pyroelectric nanogenerator, temperature difference can be triggered by external light source which does not disrupt the ZnO structure and also avoids the need for physical bending/pressing as in case of piezoelectric nanogenerator...
May 21, 2018: Nanotechnology
https://www.readbyqxmd.com/read/29781173/discourse-and-cognition-in-speakers-with-acquired-brain-injury-abi-a-systematic-review
#13
REVIEW
Elizabeth Hill, Mary Claessen, Anne Whitworth, Mark Boyes, Roslyn Ward
BACKGROUND: Cognitive impairment, particularly of executive functioning, has been implicated in deficits in spoken discourse production following acquired brain injury (ABI). However, due to variation in the methodologies and heterogeneity of findings across studies, the nature and extent of this association is not well understood. AIMS: This review aims to synthesize the literature investigating associations between cognitive deficits and discourse impairment after ABI...
May 20, 2018: International Journal of Language & Communication Disorders
https://www.readbyqxmd.com/read/29781024/the-owl-sensor-a-fragile-dna-nanostructure-for-the-analysis-of-single-nucleotide-variations
#14
Rebekah J Karadeema, Maria Stancescu, Tyler P Steidl, Sophia C Bertot, Dmitry M Kolpashchikov
Analysis of single nucleotide variations (SNVs) in DNA and RNA sequences is instrumental in healthcare for the detection of genetic and infectious diseases and drug-resistant pathogens. Here we took advantage of the developments in DNA nanotechnology to design a hybridization sensor, named the 'owl sensor', which produces a fluorescence signal only when it complexes with fully complementary DNA or RNA analytes. The novelty of the owl sensor operation is that the selectivity of analyte recognition is, at least in part, determined by the structural rigidity and stability of the entire DNA nanostructure rather than exclusively by the stability of the analyte-probe duplex, as is the case for conventional hybridization probes...
May 21, 2018: Nanoscale
https://www.readbyqxmd.com/read/29780979/entropy-connects-water-structure-and-dynamics-in-protein-hydration-layer
#15
Jayangika N Dahanayake, Katie R Mitchell-Koch
The enzyme Candida Antarctica lipase B (CALB) serves here as a model for understanding connections among hydration layer dynamics, solvation shell structure, and protein surface structure. The structure and dynamics of water molecules in the hydration layer were characterized for regions of the CALB surface, divided around each α-helix, β-sheet, and loop structure. Heterogeneous hydration dynamics were observed around the surface of the enzyme, in line with spectroscopic observations of other proteins. Regional differences in the structure of the biomolecular hydration layer were found to be concomitant with variations in dynamics...
May 21, 2018: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/29780720/uniportal-video-assisted-thoracic-surgery-treatment-of-intra-operative-complications
#16
Vasilios Tentzeris, Kostas Papagiannopoulos
Background: The uniportal video-assisted thoracic surgery (U-VATS) approach is rapidly gaining attention. Still there is lack of gross engagement to this technique, even within the VATS surgeons. We believe that the uniportal approach needs the same attention as any newly introduced skill; it would be a great mistake to be considered as a simple variation of the standardised multi-portal VATS. Methods: We have evaluated personal and institutional experience, supported by international bibliography...
2018: Journal of Visualized Surgery
https://www.readbyqxmd.com/read/29780509/self-complementary-nickel-halides-enable-multifaceted-comparisons-of-intermolecular-halogen-bonds-fluoride-ligands-vs-other-halides
#17
Vargini Thangavadivale, Pedro M Aguiar, Naseralla A Jasim, Sarah J Pike, Dan A Smith, Adrian C Whitwood, Lee Brammer, Robin N Perutz
The syntheses of three series of complexes designed with self-complementary motifs for formation of halogen bonds between an iodotetrafluorophenyl ligand and a halide ligand at square-planar nickel are reported, allowing structural comparisons of halogen bonding between all four halides C6 F4 I···X-Ni (X = F, Cl, Br, I). In the series trans -[NiX(2,3,5,6-C6 F4 I)(PEt3 )2 ] 1pX and trans -[NiX(2,3,4,5-C6 F4 I)(PEt3 )2 ] (X = F, Cl, Br, I) 1oX , the iodine substituent on the benzene ring was positioned para and ortho to the metal, respectively...
April 21, 2018: Chemical Science
https://www.readbyqxmd.com/read/29780471/direct-observation-of-supramolecular-binding-of-light-hydrocarbons-in-vanadium-iii-and-iv-metal-organic-framework-materials
#18
Zhenzhong Lu, Harry G W Godfrey, Ivan da Silva, Yongqiang Cheng, Mathew Savage, Pascal Manuel, Svemir Rudić, Anibal J Ramirez-Cuesta, Sihai Yang, Martin Schröder
Fine tuning of host-guest supramolecular interactions in porous systems enables direct control over the properties of functional materials. We report here a modification of hydrogen bonding and its effect on guest binding in a pair of redox-active metal-organic frameworks (MOFs). Oxidation of MFM-300(VIII ) {[VIII2(OH)2 (L)], LH4 = biphenyl-3,3',5,5'-tetracarboxylic acid} is accompanied by deprotonation of the bridging hydroxyl groups to afford isostructural MFM-300(VIV ), [VIV2O2 (L)]. The precise role of the hydroxyl groups, O -carboxylate centres and π-π interactions in the supramolecular binding of C2 hydrocarbons in these materials has been determined using neutron diffraction and inelastic neutron scattering, coupled with DFT modelling...
April 7, 2018: Chemical Science
https://www.readbyqxmd.com/read/29780374/insight-into-the-variation-of-bacterial-structure-in-atrazine-contaminated-soil-regulating-by-potential-phytoremediator-pennisetum-americanum-l-k-schum
#19
Bo Cao, Ying Zhang, Ziyi Wang, Mengyuan Li, Feng Yang, Duo Jiang, Zhao Jiang
Although plants of the genus Pennisetum can accelerate the removal of atrazine from its rhizosphere, the roles played by this plant in adjusting the soil environment and soil microorganism properties that might contribute to pollutant removal are incompletely understood. We selected Pennisetum americanum (L.) K. Schum ( P. americanum ) as the test plant and investigated the interaction between P. americanum and atrazine-contaminated soil, focusing on the adjustment of the soil biochemical properties as well as bacterial functional and community diversity in the rhizosphere using Biolog EcoPlates and high-throughput sequencing of the 16S rRNA gene...
2018: Frontiers in Microbiology
https://www.readbyqxmd.com/read/29780199/the-tuning-of-the-plasmon-resonance-of-the-metal-nanoparticles-in-terms-of-the-sers-effect
#20
Z Starowicz, R Wojnarowska-Nowak, P Ozga, E M Sheregii
The Surface-enhanced Raman spectroscopy is the essential tool for various levels of the molecular studies. In order to become widely used as a fast analytical tool, the enhancing structures such as the nanoparticles have to be simple, inexpensive, and offer good flexibility in enhancing properties and the spectral range. In this paper, we investigated the plasmonic properties of the metal nanoparticles, to which the molecules of interest can be adsorbed, forming the bionanocomplexes. Here, for the first time, we provided the collection of the results gathered in one article, which can serve as the basis or guidance for designing the SERS studies on different bionanocomplexes, various nanoparticle structures, sizes, and excitation wavelengths...
2018: Colloid and Polymer Science
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