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https://www.readbyqxmd.com/read/28927239/tubulins-rhythms-and-cell-walls-in-poplar-leaves-it-s-all-in-the-timing
#1
Scott A Harding, Hao Hu, Batbayar Nyamdari, Liang-Jiao Xue, Radnaa Naran, Chung-Jui Tsai
Plant cell walls exhibit architectural and compositional changes throughout their development and in response to external cues. While tubulins are involved in cell wall biogenesis, much remains unknown about the scope of their involvement during the orchestration of this resource-demanding process. A transgenic approach coupled with cell wall compositional analysis, RNA-seq and mining of publicly available diurnal gene expression data was used to assess the involvement of tubulins in poplar leaf cell wall biogenesis...
September 12, 2017: Tree Physiology
https://www.readbyqxmd.com/read/28926899/-the-quantitative-analysis-of-mr-dynamic-contrast-enhangced-imaging-on-efficacy-and-prognosis-of-transcatheter-arterial-chemoembolization-on-hepatocellular-carcinoma
#2
X H Ma, S Wang, X M Zhao, H Ouyang, M Wang, Y J Zhu, Z Zhu, C W Zhou
Objective: To investigate the prognostic value of quantitative parameters of dynamic contrast-enhangced MR (DCE-MR) on short-term efficacy of transcatheter arterial chemoembolization (TACE) on hepatocellular carcinoma(HCC). Methods: 79 patients with HCC underwent non-enhanced MR imaging and DCE on a 3.0T MR scanner before and one month after TACE. The quantitative parameters were measured on the maximal tumor region, including maximal tumor diameter(MTD), ADC, K(trans,) K(ep) and V(e) value before and after TACE...
September 23, 2017: Zhonghua Zhong Liu za Zhi [Chinese Journal of Oncology]
https://www.readbyqxmd.com/read/28926627/tiger-sharks-can-connect-equatorial-habitats-and-fisheries-across-the-atlantic-ocean-basin
#3
André S Afonso, Ricardo Garla, Fábio H V Hazin
Increasing our knowledge about the spatial ecology of apex predators and their interactions with diverse habitats and fisheries is necessary for understanding the trophic mechanisms that underlie several aspects of marine ecosystem dynamics and for guiding informed management policies. A preliminary assessment of tiger shark (Galeocerdo cuvier) population structure off the oceanic insular system of Fernando de Noronha (FEN) and the large-scale movements performed by this species in the equatorial Atlantic Ocean was conducted using longline and handline fishing gear and satellite telemetry...
2017: PloS One
https://www.readbyqxmd.com/read/28926061/network-based-modelling-and-percolation-analysis-of-conformational-dynamics-and-activation-in-the-cdk2-and-cdk4-proteins-dynamic-and-energetic-polarization-of-the-kinase-lobes-may-determine-divergence-of-the-regulatory-mechanisms
#4
G M Verkhivker
The overarching goal of delineating molecular principles underlying differentiation of the activation mechanisms in cyclin-dependent kinases (CDKs) is important for understanding regulatory divergences among closely related kinases which can be exploited in drug discovery of targeted and allosteric inhibitors. To systematically characterize dynamic, energetic and network signatures of the activation mechanisms, we combined atomistic simulations and elastic network modeling with the analysis of the residue interaction networks and rigidity decomposition of the CDK2-cyclin A and CDK4-cyclin D1/D3 complexes...
September 19, 2017: Molecular BioSystems
https://www.readbyqxmd.com/read/28926001/ketamine-differential-neurophysiological-dynamics-in-functional-networks-in-the-rat-brain
#5
A Ahnaou, H Huysmans, R Biermans, N V Manyakov, W H I M Drinkenburg
Recently, the N-methyl-d-aspartate-receptor (NMDAR) antagonist ketamine has emerged as a fast-onset mechanism to achieve antidepressant activity, whereas its psychomimetic, dissociative and amnestic effects have been well documented to pharmacologically model schizophrenia features in rodents. Sleep-wake architecture, neuronal oscillations and network connectivity are key mechanisms supporting brain plasticity and cognition, which are disrupted in mood disorders such as depression and schizophrenia. In rats, we investigated the dynamic effects of acute and chronic subcutaneous administration of ketamine (2...
September 19, 2017: Translational Psychiatry
https://www.readbyqxmd.com/read/28925354/dynamic-representation-of-partially-occluded-objects-in-primate-prefrontal-and-visual-cortex
#6
Amber M Fyall, Yasmine El-Shamayleh, Hannah Choi, Eric Shea-Brown, Anitha Pasupathy
Successful recognition of partially occluded objects is presumed to involve dynamic interactions between brain areas responsible for vision and cognition, but neurophysiological evidence for the involvement of feedback signals is lacking. Here, we demonstrate that neurons in the ventrolateral prefrontal cortex (vlPFC) of monkeys performing a shape discrimination task respond more strongly to occluded than unoccluded stimuli. In contrast, neurons in visual area V4 respond more strongly to unoccluded stimuli...
September 19, 2017: ELife
https://www.readbyqxmd.com/read/28924658/two-photon-sted-microscopy-for-nanoscale-imaging-of-neural-morphology-in-vivo
#7
Mirelle J T Ter Veer, Thomas Pfeiffer, U Valentin Nägerl
The advent of super-resolution microscopy offers to bridge the gap between electron and light microscopy. It has opened up the possibility of visualizing cellular structures and dynamic signaling events on the "mesoscale" well below the classic diffraction barrier of light microscopy (10-200 nm), while essentially retaining the advantages of fluorescence microscopy concerning multicolor labeling, detection sensitivity, signal contrast, live-cell imaging, and temporal resolution.From among the new super-resolution techniques, STED microscopy stands out as a laser-scanning imaging modality, which enables nanoscale volume-metric imaging of cellular morphology...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28923914/new-ultrasound-techniques-promise-further-advances-in-aki-and-ckd
#8
REVIEW
Travis D Hull, Anupam Agarwal, Kenneth Hoyt
AKI and CKD are important clinical problems because they affect many patients and the associated diagnostic and treatment paradigms are imperfect. Ultrasound is a cost-effective, noninvasive, and simple imaging modality that offers a multitude of means to improve the diagnosis, monitoring, and treatment of both AKI and CKD, especially considering recent advances in this technique. Ultrasound alone can attenuate AKI and prevent CKD by stimulating the splenic cholinergic anti-inflammatory pathway. Additionally, microbubble contrast agents are improving the sensitivity and specificity of ultrasound for diagnosing kidney disease, especially when these agents are conjugated to ligand-specific mAbs or peptides, which make the dynamic assessment of disease progression and response to treatment possible...
September 18, 2017: Journal of the American Society of Nephrology: JASN
https://www.readbyqxmd.com/read/28923128/-items-for-criticism-not-in-sequence-joseph-delee-pare-lorentz-and-the-fight-for-life-1940
#9
Caitjan Gainty
In the late 1920s, the American obstetrician Joseph DeLee brought the motion-picture camera into the birth room. Following that era's trend of adapting industrial efficiency practices for medical environments, DeLee's films give spectacular and unexpected expression to the engineering concept of 'streamlining'. Accomplishing what more tangible obstetric streamlining practices had failed to, DeLee's cameras, and his post-production manipulation, shifted birth from messy and dangerous to rationalized, efficient, death-defying...
September 2017: British Journal for the History of Science
https://www.readbyqxmd.com/read/28922717/magnetic-nanoparticle-loaded-alginate-beads-for-local-micro-actuation-of-in-vitro-tissue-constructs
#10
Awatef M Alshehri, Otto C Wilson, Bishnu Dahal, John Philip, Xiaolong Luo, Christopher B Raub
Magnetic nanoparticles (MNPs) self-align and transduce magnetic force, two properties which lead to promising applications in cell and tissue engineering. However, the toxicity of MNPs to cells which uptake them is a major impediment to applications in engineered tissue constructs. To address this problem, MNPs were embedded in millimeter-scale alginate beads, coated with glutaraldehyde cross-linked chitosan, and loaded in acellular and MDA-MB-231 cancer cell-seeded collagen hydrogels, providing local micro-actuation under an external magnetic field...
September 4, 2017: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/28922524/dynamic-contrast-enhanced-mri-in-orbital-lymphoproliferative-disorders-effects-of-region-of-interest-selection-methods-on-time-efficiency-measurement-reproducibility-and-diagnostic-ability
#11
Wen Qian, Xiao-Quan Xu, Hao Hu, Guo-Yi Su, Jiang-Fen Wu, Hai-Bin Shi, Fei-Yun Wu
BACKGROUND: Previous studies indicated that dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) could serve as a useful biomarker for differentiating malignant from benign orbital lymphoproliferative disorders (OLPDs). PURPOSE: To investigate the influence of different region of interest (ROI) selection methods on the measurements of DCE-MRI parameters, and their diagnostic ability in discriminating malignant from benign OLPDs. STUDY TYPE: Retrospective study...
September 18, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28922115/colour-constancy-beyond-the-classical-receptive-field
#12
Arash Akbarinia, C Alejandro Parraga
The problem of removing illuminant variations to preserve the colours of objects (colour constancy) has already been solved by the human brain using mechanisms that rely largely on centre-surround computations of local contrast. In this paper we adopt some of these biological solutions described by long known physiological findings into a simple, fully automatic, functional model (termed Adaptive Surround Modulation or ASM). In ASM, the size of a visual neuron's receptive field (RF) as well as the relationship with its surround varies according to the local contrast within the stimulus, which in turn determines the nature of the centre-surround normalisation of cortical neurons higher up in the processing chain...
September 18, 2017: IEEE Transactions on Pattern Analysis and Machine Intelligence
https://www.readbyqxmd.com/read/28921952/nano-air-seeds-trapped-in-mesoporous-janus-nanoparticles-facilitate-cavitation-and-enhance-ultrasound-imaging
#13
Konstantin Tamarov, Andrey Sviridov, Wujun Xu, Markus Malo, Valery Andreev, Victor Yu Timoshenko, Vesa-Pekka Lehto
The current contrast agents utilized in ultrasound (US) imaging are based on microbubbles which, however, suffer from a short lifetime in the systemic circulation. The present study introduces a new type of contrast agents for US imaging based on bioresorbable Janus nanoparticles (NPs) that are able to generate microbubbles in situ under US radiation for extended time. The Janus NPs were fabricated from porous silicon (PSi) that was modified via a nanostopper technique. The technique was exploited to prepare PSi NPs which had hydrophobic pore walls (inner face) while the external surfaces of the NPs (outer face) were hydrophilic...
September 18, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28921508/selection-on-skewed-characters-and-the-paradox-of-stasis
#14
Suzanne Bonamour, Céline Teplitsky, Anne Charmantier, Pierre-André Crochet, Luis-Miguel Chevin
Observed phenotypic responses to selection in the wild often differ from predictions based on measurements of selection and genetic variance. An overlooked hypothesis to explain this paradox of stasis is that a skewed phenotypic distribution affects natural selection and evolution. We show through mathematical modelling that, when a trait selected for an optimum phenotype has a skewed distribution, directional selection is detected even at evolutionary equilibrium, where it causes no change in the mean phenotype...
September 18, 2017: Evolution; International Journal of Organic Evolution
https://www.readbyqxmd.com/read/28920598/interaction-between-h2o-n2-co-no-no2-and-n2o-molecules-and-a-defective-wse2-monolayer
#15
Dongwei Ma, Benyuan Ma, Zhiwen Lu, Chaozheng He, Yanan Tang, Zhansheng Lu, Zongxian Yang
In this study, the interaction between gas molecules, including H2O, N2, CO, NO, NO2 and N2O, and a WSe2 monolayer containing an Se vacancy (denoted as VSe) has been theoretically studied. Theoretical results show that H2O and N2 molecules are highly prone to be physisorbed on the VSe surface. The presence of the Se vacancy can significantly enhance the sensing ability of the WSe2 monolayer toward H2O and N2 molecules. In contrast, CO and NO molecules highly prefer to be molecularly chemisorbed on the VSe surface with the non-oxygen atom occupying the Se vacancy site...
September 18, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28919900/preliminary-studies-to-characterize-the-temporal-variation-of-micronutrient-composition-of-the-above-ground-organs-of-maize-and-correlated-uptake-rates
#16
Karla Vilaça Martins, Durval Dourado-Neto, Klaus Reichardt, Quirijn de Jong van Lier, José Laércio Favarin, Felipe Fadel Sartori, Guilherme Felisberto, Simone da Costa Mello
The improvement of agronomic practices and the use of high technology in field crops contributes for significant increases in maize productivity, and may have altered the dynamics of nutrient uptake and partition by the plant. Official recommendations for fertilizer applications to the maize crop in Brazil and in many countries are based on critical soil nutrient contents and are relatively outdated. Since the factors that interact in an agricultural production system are dynamic, mathematical modeling of the growth process turns out to be an appropriate tool for these studies...
2017: Frontiers in Plant Science
https://www.readbyqxmd.com/read/28919234/effects-of-periplasmic-chaperones-and-membrane-thickness-on-bama-catalysed-outer-membrane-protein-folding
#17
Bob Schiffrin, Antonio N Calabrese, Anna J Higgins, Julia R Humes, Alison E Ashcroft, Antreas C Kalli, David J Brockwell, Sheena E Radford
The biogenesis of outer membrane proteins (OMPs) in Gram-negative bacteria involves delivery by periplasmic chaperones to the β-barrel assembly machinery (BAM) which catalyses OMP insertion into the outer membrane (OM). Here, we examine the effects of membrane thickness, the E. coli periplasmic chaperones Skp and SurA, and BamA, the central subunit of the BAM complex, on the folding kinetics of a model OMP (tOmpA) using fluorescence spectroscopy, native mass spectrometry, and molecular dynamics (MD) simulations...
September 15, 2017: Journal of Molecular Biology
https://www.readbyqxmd.com/read/28919161/magnetic-resonance-elastography-of-the-brain-a-comparison-between-pigs-and-humans
#18
Johannes Weickenmeier, Mehmet Kurt, Efe Ozkaya, Max Wintermark, Kim Butts Pauly, Ellen Kuhl
Magnetic resonance elastography holds promise as a non-invasive, easy-to-use, in vivo biomarker for neurodegenerative diseases. Throughout the past decade, pigs have gained increased popularity as large animal models for human neurodegeneration. However, the volume of a pig brain is an order of magnitude smaller than the human brain, its skull is 40% thicker, and its head is about twice as big. This raises the question to which extent established vibration devices, actuation frequencies, and analysis tools for humans translate to large animal studies in pigs...
August 26, 2017: Journal of the Mechanical Behavior of Biomedical Materials
https://www.readbyqxmd.com/read/28918633/axisymmetric-and-non-axisymmetric-oscillations-of-sessile-compound-droplets-in-open-digital-microfluidic-platform
#19
Shubhi Bansal, Prosenjit Sen
Manipulating droplets of biological fluids in Electrowetting on Dielectric (EWOD) based digital microfluidic platform is a significant challenge due to biofouling and surface contamination. This problem is often addressed by operating in an oil environment. We study an alternate configuration of sessile compound droplets having an aqueous core surrounded by a smaller oil shell. In contrast to conventional EWOD, open digital microfluidic platform enabled by the core-shell configuration will allow electrical, mechanical or optical probes to get unrestricted access to the droplet and thus enabling highly flexible and dynamically reconfigurable lab-on-chip systems...
September 18, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28917540/galba-truncatula-and-fasciola-hepatica-genetic-costructures-and-interactions-with-intermediate-host-dispersal
#20
Ana C Correa, Thierry De Meeûs, Gilles Dreyfuss, Daniel Rondelaud, Sylvie Hurtrez-Boussès
Antagonistic interactions between hosts and parasites are key structuring forces in natural populations. Demographic factors like extinction, migration and the effective population size shape host-parasite metapopulational dynamics. Therefore, to understand the evolution of host-parasite systems it is necessary to study the distribution of the genetic variation of both entities simultaneously. In this paper, we investigate the population genetics co-structure of parasites and hosts within a metapopulation of the liver fluke, Fasciola hepatica, and two of its intermediate hosts, the main intermediate host in Europe, Galba truncatula, and a new intermediate host, Omphiscola glabra, in Central France...
September 13, 2017: Infection, Genetics and Evolution
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