bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evolutionary dynamics of mycorrhizal symbiosis in land plant diversification
Authors: Feijen Frida A. A. , Vos Rutger A. , Nuytinck Jorinde , Merckx Vincent S. F. T. 
Published: July 2018

AbstractMycorrhizal symbiosis between soil fungi and land plants is one of the most widespread and ecologically important mutualisms on earth. It has long been hypothesized that the Glomeromycotina, the mycorrhizal symbionts of the majority of plants, facilitated colonization of land by plants in the Ordovician. This view was recently challenged by the discovery of mycorrhiza-like associations with Mucoromycotina in several early diverging lineages of land plants. Utilizing a large, species-level database of plants’ mycorrhiza-like associations and a Bayesian approach to state transition dynamics we here show that the recruitment of Mucoromycotina is the best supported transition from a non-mycorrhizal state. We further found that transitions between different combinations of either or both of Mucoromycotina and Glomeromycotina occur at high rates, and found similar promiscuity among combinations that include either or both of Glomeromycotina and Ascomycota with a nearly fixed association with Basidiomycota. Our results portray an evolutionary scenario of evolution of mycorrhizal symbiosis with a prominent role for Mucoromycotina in the early stages of land plant diversification.
Fabrication of graphene film composite electrochemical biosensor as a pre-screening algal toxin detection tool in the event of water contamination
Authors: Zhang Wei , Jia Baoping , Furumai Hiroaki 
Published: July 2018

AbstractIn this work, we fabricated a novel graphene film composite biosensor for microcystin-LR detection as an alternative to time-consuming, expensive, non-portable and often skills-demanding conventional methods of analysis involved in water quality monitoring and assessment. Excellent linear correlation (R2 = 0.99) of the electron-transfer resistance was achieved over a wide range of microcystin-LR (MC-LR) concentration, i.e. 0.005–10 μg/L. As-prepared graphene film composite biosensors can specifically detect MC-LR with remarkable sensitivity and detection limit (2.3 ng/L) much lower than the World Health Organization (WHO) provisional guideline limit of microcystin-LR concentration (i.e. 1 μg/L) in different water sources. Their great potential can be attributed to large active surface area of graphene film and efficient charge transfer process enabled by their high conductivity. Developed graphene film composite biosensors were also successfully applied to determination of MC-LR in several environmental water samples with high detection recovery, which offers a promising possibility of large-scale manufacture of sensor tips due to their macroscopic free-standing nature, the scalable fabrication route and easily tunable size.
Transient and Persistent UP States during Slow-wave Oscillation and their Implications for Cell-Assembly Dynamics
Authors: Fung Chi Chung Alan , Fukai Tomoki 
Published: July 2018

AbstractThe membrane potentials of cortical neuronsin vivoexhibit spontaneous fluctuations between a depolarized UP state and a resting DOWN state during the slow-wave sleeps or in the resting states. This oscillatory activity is believed to engage in memory consolidation although the underlying mechanisms remain unknown. Recently, it has been shown that UP-DOWN state transitions exhibit significantly different temporal profiles in different cortical regions, presumably reflecting differences in the underlying network structure. Here, we studied in computational models whether and how the connection configurations of cortical circuits determine the macroscopic network behavior during the slow-wave oscillation. Inspired by cortical neurobiology, we modeled three types of synaptic weight distributions, namely, log-normal, sparse log-normal and sparse Gaussian. Both analytic and numerical results suggest that a larger variance of weight distribution results in a larger chance of having significantly prolonged UP states. However, the different weight distributions only produce similar macroscopic behavior. We further confirmed that prolonged UP states enrich the variety of cell assemblies activated during these states. Our results suggest the role of persistent UP states for the prolonged repetition of a selected set of cell assemblies during memory consolidation.
A lower dose of intravitreal conbercept effectively treats retinopathy of prematurity
Authors: Cheng Yong , Meng Qingyu , Linghu Dandan , Zhao Mingwei , Liang Jianhong 
Published: July 2018

AbstractIntravitreal Conbercept (IVC) is the latest applied and effective treatment for the management of retinopathy of prematurity (ROP). However, conbercept escapes from the vitreous into the general circulation and reduce systemic VEGF concentrations. Thus, there are concerns about systemic complications, in these premature infants who are developing vital organ systems. This study is to determine whether a low dosage (0.15 mg/0.015 mL) of IVC is effective in the treatment of Zone II Stage 2/3 + ROP. A total of 38 eyes of 20 infants were analyzed retrospectively. We identified treatment effectiveness as complete regression of retinopathy and retinal vascularisation to zone III. The mean gestational age (GA), postmenstrual age (PMA) at treatment and birth weights (BW) were 28.6 ± 2.2 weeks, 39.3 ± 3.0 weeks and 1297.5 ± 429.2 g respectively. Primary effectiveness (react to IVC 0.15 mg alone) was found in 32/38 eyes (84.2%). Secondary effectiveness (a second IVC was required) was found in 6/38 eyes (15.8%). Follow-up continued until 90 weeks’ postmenstrual age and showed no recurrences of plus disease or neovascularization. The study suggests 0.15 mg IVC is effective for Zone II Stage 2/3 + ROP, and there is no adverse ocular outcomes during the follow-up period.
Arylic C–X Bond Activation by Palladium Catalysts: Activation Strain Analyses of Reactivity Trends
Authors: Vermeeren Pascal , Sun Xiaobo , Bickelhaupt F. Matthias 
Published: July 2018

AbstractWe have quantum chemically explored arylic carbon–substituent bond activation via oxidative insertion of a palladium catalyst in C6H5X + PdLnmodel systems (X = H, Cl, CH3; Ln = no ligand, PH3, (PH3)2, PH2C2H4PH2) using relativistic density functional theory at ZORA-BLYP/TZ2P. Besides exploring reactivity trends and comparing them to aliphatic C–X activation, we aim at uncovering the physical factors behind the activity and selectivity. Our results show that barriers for arylic C–X activation are lower than those for the corresponding aliphatic C–X bonds. However, trends along bonds or upon variation of ligands are similar. Thus, bond activation barriers increase along C–Cl < C–H < C–C and along Pd < Pd(PH3) or Pd(PH2C2H4PH2) < Pd(PH3)2. Activation strain analyses in conjunction with quantitative molecular orbital theory trace these trends to the rigidity and bonding capability of the various C–X bonds, model catalysts, and ligands.
Timing correlations between cerebellar interpositus neuronal firing and classically conditioned eyelid responses in wild-type and Lurcher mice
Authors: López-Ramos Juan C. , Houdek Zbynek , Cendelín Jan , Vožeh Frantisek , Delgado-García José M. 
Published: July 2018

AbstractClassical eyeblink conditioning is an experimental model widely used for the study of the neuronal mechanisms underlying the acquisition of new motor and cognitive skills. There are two principal interpretations of the role of the cerebellum in the learning of eyelid conditioned responses (CRs). One considers that the cerebellum is the place where this learning is acquired and stored, while the second suggests that the cerebellum is mostly involved in the proper performance of acquired CRs, implying that there must be other brain areas involved in the learning process. We checked the timing of cerebellar interpositus nucleus (IPN) neurons’ firing rate with eyelid CRs in both wild-type (WT) and Lurcher (a model of cerebellar cortex degeneration) mice. We used delay and trace conditioning paradigms. WT mice presented a better execution for delay vs. trace conditioning and also for these two paradigms than did Lurcher mice. IPN neurons were activated during CRs following the activation of the orbicularis oculi muscle. Firing patterns of IPN neurons were altered in Lurcher mice. In conclusion, the cerebellum seems to be mostly related with the performance of conditioned responses, rather than with their acquisition.
Structural cortical network reorganization associated with early conversion to multiple sclerosis
Authors: Tur C. , Eshaghi A. , Altmann D. R. , Jenkins T. M. , Prados F. , Grussu F. , Charalambous T. , Schmidt A. , Ourselin S. , Clayden J. D. , Wheeler-Kingshott C. A. M. G. , Thompson A. J. , Ciccarelli O. , Toosy A. T. 
Published: July 2018

AbstractBrain structural covariance networks (SCNs) based on pairwise statistical associations of cortical thickness data across brain areas reflect underlying physical and functional connections between them. SCNs capture the complexity of human brain cortex structure and are disrupted in neurodegenerative conditions. However, the longitudinal assessment of SCN dynamics has not yet been explored, despite its potential to unveil mechanisms underlying neurodegeneration. Here, we evaluated the changes of SCNs over 12 months in patients with a first inflammatory-demyelinating attack of the Central Nervous System and assessed their clinical relevance by comparing SCN dynamics of patients with and without conversion to multiple sclerosis (MS) over one year. All subjects underwent clinical and brain MRI assessments over one year. Brain cortical thicknesses for each subject and time point were used to obtain group-level between-area correlation matrices from which nodal connectivity metrics were obtained. Robust bootstrap-based statistical approaches (allowing sampling with replacement) assessed the significance of longitudinal changes. Patients who converted to MS exhibited significantly greater network connectivity at baseline than non-converters (p = 0.02) and a subsequent connectivity loss over time (p = 0.001–0.02), not observed in non-converters’ network. These findings suggest SCN analysis is sensitive to brain tissue changes in early MS, reflecting clinically relevant aspects of the condition. However, this is preliminary work, indicated by the low sample sizes, and its results and conclusions should be treated with caution and confirmed with larger cohorts.
Hyperthermia induces therapeutic effectiveness and potentiates adjuvant therapy with non-targeted and targeted drugs in an in vitro model of human malignant melanoma
Authors: Mantso T. , Vasileiadis S. , Anestopoulos I. , Voulgaridou G. P. , Lampri E. , Botaitis S. , Kontomanolis E. N. , Simopoulos C. , Goussetis G. , Franco R. , Chlichlia K. , Pappa A. , Panayiotidis M. I. 
Published: July 2018

AbstractIn the present study, we have aimed to characterize the intrinsic, extrinsic and ER-mediated apoptotic induction by hyperthermia in an in vitro model of human malignant melanoma and furthermore, to evaluate its therapeutic effectiveness in an adjuvant therapeutic setting characterized by combinational treatments with non-targeted (Dacarbazine & Temozolomide) and targeted (Dabrafenib & Vemurafenib) drugs. Overall, our data showed that both low (43 °C) and high (45 °C) hyperthermic exposures were capable of inducing cell death by activating all apoptotic pathways but in a rather distinct manner. More specifically, low hyperthermia induced extrinsic and intrinsic apoptotic pathways both of which activated caspase 6 only as opposed to high hyperthermia which was mediated by the combined effects of caspases 3, 7 and 6. Furthermore, significant involvement of the ER was evident (under both hyperthermic conditions) suggesting its role in regulating apoptosis via activation of CHOP. Our data revealed that while low hyperthermia activated IRE-1 and ATF6 only, high hyperthermia induced activation of PERK as well suggesting that ultimately these ER stress sensors can lead to the induction of CHOP via different pathways of transmitted signals. Finally, combinational treatment protocols revealed an effect of hyperthermia in potentiating the therapeutic effectiveness of non-targeted as well as targeted drugs utilized in the clinical setting. Overall, our findings support evidence into hyperthermia’s therapeutic potential in treating human malignant melanoma by elucidating the underlying mechanisms of its complex apoptotic induction.
Phenotype of p53 wild-type epitope-specific T cells in the circulation of patients with head and neck cancer
Authors: Albers Andreas E. , Qian Xu , Kaufmann Andreas M. , Mytilineos Daphne , Ferris Robert L. , Hoffmann Thomas K. , DeLeo Albert B. 
Published: July 2018

AbstractCD8+ cytotoxic T-cell (CTL) specific for non-mutated, wild type (wt) sequence p53 peptides derived from wt or mutant p53 molecules expressed in head and neck squamous cell carcinomas (HNSCC) have been detected in the circulation of patients with this disease. The frequency and differentiation/maturation phenotypes of these anti-tumor specific CTL can reflect the host’s immunologic response. Therefore, we investigated the frequency and phenotypes of wt sequence p53 peptide-specific CTL in patients with HNSCC (n = 33) by flow cytometric analysis using HLA-A*0201 tetrameric peptides (tet) complexed with the wt sequence p53264–272 or p53149–157 peptide and co-staining with phenotypic markers. One main finding was that increasing frequencies of tet+ CD8+ T cells in patients’ circulation correlated with increased frequencies of inactive naïve tet+ cells, while those with effector memory and terminally differentiated phenotypes, which are associated with positive anti-tumor immune responses, decreased. We also found that the frequency of circulating tet+ CD8+ T cells negatively correlated with p53 expression in tumor tissues and tumor stage. Our findings support further clinical-based investigations to define the frequencies and phenotypes of wt sequence p53 peptide-specific CD8+ T cells to predict disease severity, enhance selection of patients for inclusion in vaccination trials and highlight prerequisites to enhance immune susceptibility by activation of inactive naïve tet+ T cells and/or enhancing circulating effector T cell activity by checkpoint blockage.
Structural Insight into Substrate Specificity of 3-Hydroxypropionyl-Coenzyme A Dehydratase from Metallosphaera sedula
Authors: Lee Donghoon , Kim Kyung-Jin 
Published: July 2018

AbstractMetallosphaera sedulais a thermoacidophilic autotrophic archaeon known to utilize the 3-hydroxypropionate/4-hydroxybutyrate cycle (3-HP/4-HB cycle) as carbon fixation pathway. 3-Hydroxypropionyl-CoA dehydratase (3HPCD) is an enzyme involved in the 3-HP/4-HB cycle by converting 3-hydroxypropionyl-CoA to acryloyl-CoA. To elucidate the molecular mechanism of 3HPCD fromM. sedula(Ms3HPCD), we determined its crystal structure in complex with Coenzyme A (CoA).Ms3HPCD showed an overall structure and the CoA-binding mode similar to other enoyl-CoA hydratase (ECH) family enzymes. However, compared with the other ECHs,Ms3HPCD has a tightly formed α3 helix near the active site, and bulky aromatic residues are located at the enoyl-group binding site, resulting in the enzyme having an optimal substrate binding site for accepting short-chain 3-hydroxyacyl-CoA as a substrate. Moreover, based on the phylogenetic tree analysis, we propose that the 3HPCD homologues from the phylumCrenarchaeotahave an enoyl-group binding pocket similar to that of bacterial short-chain ECHs.
Genetic characterization and pathogenic potential of H10 avian influenza viruses isolated from live poultry markets in Bangladesh
Authors: El-Shesheny Rabeh , Franks John , Marathe Bindumadhav M. , Hasan M. Kamrul , Feeroz Mohammed M. , Krauss Scott , Vogel Peter , McKenzie Pamela , Webby Richard J. , Webster Robert G. 
Published: July 2018

AbstractFatal human cases of avian-origin H10N8 influenza virus infections have raised concern about their potential for human-to-human transmission. H10 subtype avian influenza viruses (AIVs) have been isolated from wild and domestic aquatic birds across Eurasia and North America. We isolated eight H10 AIVs (four H10N7, two H10N9, one H10N1, and one H10N6) from live poultry markets in Bangladesh. Genetic analyses demonstrated that all eight isolates belong to the Eurasian lineage. HA phylogenetic and antigenic analyses indicated that two antigenically distinct groups of H10 AIVs are circulating in Bangladeshi live poultry markets. We evaluated the virulence of four representative H10 AIV strains in DBA/2J mice and found that they replicated efficiently in mice without prior adaptation. Moreover, H10N6 and H10N1 AIVs caused high mortality with systemic dissemination. These results indicate that H10 AIVs pose a potential threat to human health and the mechanisms of their transmissibility should be elucidated.
Design principles of the paradoxical feedback between pancreatic alpha and beta cells
Authors: Garzilli Immacolata , Itzkovitz Shalev 
Published: July 2018

AbstractMammalian glucose homeostasis is controlled by the antagonistic hormones insulin and glucagon, secreted by pancreatic beta and alpha cells respectively. These two cell types are adjacently located in the islets of Langerhans and affect each others’ secretions in a paradoxical manner: while insulin inhibits glucagon secretion from alpha cells, glucagon seems to stimulate insulin secretion from beta cells. Here we ask what are the design principles of this negative feedback loop. We systematically simulate the dynamics of all possible islet inter-cellular connectivity patterns and analyze different performance criteria. We find that the observed circuit dampens overshoots of blood glucose levels after reversion of glucose drops. This feature is related to the temporal delay in the rise of insulin concentrations in peripheral tissues, compared to the immediate hormone action on the liver. In addition, we find that the circuit facilitates coordinate secretion of both hormones in response to protein meals. Our study highlights the advantages of a paradoxical paracrine feedback loop in maintaining metabolic homeostasis.
In utero gene expression in the Slc39a8(neo/neo) knockdown mouse
Authors: Chen Jing , Gálvez-Peralta Marina , Zhang Xiang , Deng Jingyuan , Liu Zijuan , Nebert Daniel W. 
Published: July 2018

AbstractSlc39a8 encodes ZIP8, a divalent cation/bicarbonate symporter expressed in pluripotent mouse embryonic stem cells, and therefore ubiquitous in adult tissues; ZIP8 influxes Zn2+, Mn2+and Fe2+.Slc39a8(neo/neo)knockdown mice exhibit 10–15% of wild-type ZIP8 mRNA and protein levels, and show pleiotropic phenotype of stunted growth, neonatal lethality, multi-organ dysmorphogenesis, and dysregulated hematopoiesis manifested as severe anemia. Herein we performed RNA-seq analysis of gestational day (GD)13.5 yolk sac and placenta, and GD16.5 liver, kidney, lung, heart and cerebellum, comparingSlc39a8(neo/neo)withSlc39a8(+/+) wild-type. Meta-data analysis of differentially-expressed genes revealed 29 unique genes from all tissues — having enriched GO categories associated with hematopoiesis and hypoxia and KEGG categories of complement, response to infection, and coagulation cascade — consistent with dysregulated hematopoietic stem cell fate. Based on transcription factor (TF) profiles in the JASPAR database, and searching for TF-binding sites enriched by Pscan, we identified numerous genes encoding zinc-finger and other TFs associated with hematopoietic stem cell functions. We conclude that, in this mouse model, deficient ZIP8-mediated divalent cation transport affects zinc-finger (e.g. GATA proteins) and other TFs interacting with GATA proteins (e.g. TAL1), predominantly in yolk sac. These data strongly support the phenotype of dysmorphogenesis and anemia seen inSlc39a8(neo/neo)mice in utero.
Iodine k-edge dual energy imaging reveals the influence of particle size distribution on solute transport in drying porous media
Authors: Shokri-Kuehni Salomé M. S. , Bergstad Mina , Sahimi Muhammad , Webb Colin , Shokri Nima 
Published: July 2018

AbstractIncreasing salinity in groundwater and soil poses a threat to water and land resources. With the expectation of major changes to the hydrological cycle through climate change, the need for understanding the fundamental processes governing solute transport through soil has grown significantly. We provide experimentally verified insights into the influence of particle size distribution on solute transport in porous media during evaporation at the pore- and macro-scales. To do so, we utilized four-dimensional (space plus time) synchrotron X-ray tomography for iodine k-edge dual energy imaging to obtain solute concentration profiles in every single pore during saline water evaporation from coarse- and fine-grained sands. Close to the surface of the coarse-grained sand significantly higher salt concentrations were observed when compared to fine-grained sand with the same porosity under similar cumulative evaporative mass losses. The physics behind this behaviour was delineated using the recorded data with high spatial and temporal resolutions. Moreover, the measured data enabled us to quantify the variations of the effective dispersion coefficient during evaporation and how it is influenced by the particle size distribution. We show that, contrary to common assumption in modelling of solute transport during evaporation, the effective dispersion coefficient varies as a function of liquid saturation and the length of the invaded zone during evaporation from porous media, and that it increases as liquid saturation decreases.
Removal of Mn (II) by Sodium Alginate/Graphene Oxide Composite Double-Network Hydrogel Beads from Aqueous Solutions
Authors: Yang Xiuzhen , Zhou Tengzhi , Ren Bozhi , Hursthouse Andrew , Zhang Yuezhou 
Published: July 2018

AbstractAfter the successful preparation of empirical double network hydrogel beads from graphene oxide/sodium alginate(GO/SA), its cationic metal adsorption performance in aqueous solutions were investigated. Taking Mn(II) as an example, the contribution of several factors including pH, bead dosage, temperature, contact time and initial concentration ions to adsorption efficiency were examined. The Transmission Electron Microscopy (TEM) results indicate that the GO/SA double (GAD) network hydrogel bead strongly interpenetrate and the adsorption of Mn(II) is mainly influenced by solution pH, bead dose and temperature. The GAD beads exhibit an excellent adsorption capacity of 56.49 mg g−1. The adsorption process fit both Pseudo-second order kinetic model (R2 > 0.97) and the Freundlich adsorption isotherm (R2 > 0.99) and is spontaneous. After seven rounds of adsorption-desorption cycle, the adsorption capacity of GAD hydrogel remained unchanged at 18.11 mg/g.