1,108 research outputs found

    Diaqua­bis[5-(2-pyrid­yl)tetra­zolato-κ2 N 1,N 5]iron(II)

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    The title complex, [Fe(C6H4N5)2(H2O)2], was synthesized by the reaction of ferrous sulfate with 5-(2-pyrid­yl)-2H-tetra­zole (HL). The FeII atom, located on a crystallographic center of inversion, is coordinated by four N-atom donors from two planar trans-related deprotonated L ligands and two O atoms from two axial water mol­ecules in a distorted octa­hedral geometry. The FeII mononuclear units are further connected by inter­molecular O—H⋯N and C—H⋯O hydrogen-bonding inter­actions, forming a three-dimensional framework

    A Pontine Region is a Neural Correlate of the Human Affective Processing Network

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    The in vivo neural activity of the pons during the perception of affective stimuli has not been studied despite the strong implications of its role in affective processing. To examine the activity of the pons during the viewing of affective stimuli, and to verify its functional and structural connectivity with other affective neural correlates, a multimodal magnetic resonance imaging methodology was employed in this study. We observed the in vivo activity of the pons when viewing affective stimuli. Furthermore, small-world connectivity indicated that the functional connectivity (FC) between the pons and the cortico-limbic affective regions was meaningful, with the coefficient λ being positively associated with self-reported emotional reactivity. The FC between the pons and the cortico-limbic-striatal areas was related to self-reported negative affect. Corroborating this finding was the observation that the tract passing through the pons and the left hippocampus was negatively related to self-reported positive affect and positively correlated with emotional reactivity. Our findings support the framework that the pons works conjunctively with the distributed cortico-limbic-striatal systems in shaping individuals' affective states and reactivity. Our work paves the path for future research on the contribution of the pons to the precipitation and maintenance of affective disorders.published_or_final_versio

    Automated Analysis of Cryptococcal Macrophage Parasitism Using GFP-Tagged Cryptococci

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    The human fungal pathogens Cryptococcus neoformans and C. gattii cause life-threatening infections of the central nervous system. One of the major characteristics of cryptococcal disease is the ability of the pathogen to parasitise upon phagocytic immune effector cells, a phenomenon that correlates strongly with virulence in rodent models of infection. Despite the importance of phagocyte/Cryptococcus interactions to disease progression, current methods for assaying virulence in the acrophage system are both time consuming and low throughput. Here, we introduce the first stable and fully characterised GFP–expressing derivatives of two widely used cryptococcal strains: C. neoformans serotype A type strain H99 and C. gattii serotype B type strain R265. Both strains show unaltered responses to environmental and host stress conditions and no deficiency in virulence in the macrophage model system. In addition, we report the development of a method to effectively and rapidly investigate macrophage parasitism by flow cytometry, a technique that preserves the accuracy of current approaches but offers a four-fold improvement in speed

    A Sweet Killer: Mesoporous Polysaccharide Confined Silver Nanoparticles for Antibacterial Applications

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    Silver nanoparticles (AgNP) confined within porous starch have been prepared in a simple, green and efficient manner, utilising the nanoporous structure of predominantly mesoporous starch (MS) to act as nanoparticle stabiliser, support and reducing surface. MS/AgNP materials present high surface areas (SBET > 150 m2 g−1) and mesopore volumes (Vmeso > 0.45 cm3 g−1). The interaction of the AgNP precursor and forming nanoparticle nuclei with the mesoporous domains of the porous polysaccharide, direct porosity to increasingly narrower and more defined pore size distributions, indicative of a degree of cooperative assembly. Transmission electron microscopy images indicated the presence of spherical AgNP of a size reflective of the porous polysaccharide mesopore diameter (e.g., 5–25 nm), whilst XPS analysis confirmed the metallic Ag0 state. Materials were prepared at relatively low Ag loadings (<0.18 mmol g−1), demonstrating excellent antimicrobial activity in solid and liquid phase testing against Gram negative (E. coli) and positive (S. aureus) model bacteria. The resulting materials are biocompatible and present a useful solid porous carbohydrate-based polymer vehicle to control the AgNP size regime and facilitate transference to a biological environment

    The effectiveness of Baduanjin exercise for hypertension: a systematic review and meta-analysis of randomized controlled trials

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    Background: Hypertension, a major risk factor of cardiovascular mortality, is a critical issue for public health. Although Baduanjin (Eight Brocades, EB), a traditional Chinese exercise, might influence blood pressure, glucose, and lipid status, the magnitude of true effects and subgroup differences remains unclear. Therefore, we performed a systematic review of relevant randomized controlled trials (RCTs) to evaluate the effect of EB on patient-important outcomes. Methods: We systematically searched PubMed, the Cochrane Library, Web of Science, and Chinese databases since inception until March 30, 2020. Meta-analysis was carried out using "meta"package in R 3.4.3 software. A prespecified subgroup analysis was done according to the type of comparisons between groups, and the credibility of significant subgroup effects (P < 0.05) were accessed using a five-criteria list. A GRADE evidence profile was constructed to illustrate the certainty of evidence. Results: Our meta-analysis, including 14 eligible trials with 1058 patients, showed that compared with routine treatment or health education as control groups, the mean difference (MD) in systolic blood pressure (SBP) of the EB groups was - 8.52 mmHg (95%CI:[- 10.65, - 6.40], P < 0.01) and diastolic blood pressure (DBP) was - 4.65 mmHg (95%CI: [- 6.55, - 2.74], P < 0.01). For blood pressure, the evidence was, however, of low certainty because of risk of bias and inconsistency, and for the outcomes of most interest to patients (cardiovascular morbidity and mortality directly), of very low certainty (measurement of surrogate only). Subgroup analysis showed there was no significant interaction effect between different type of comparisons (SBP P = 0.15; DBP P = 0.37), so it could be easily attributed to chance. Conclusion: Regularly EB exercising may be helpful to control blood pressure, but the evidence is only low certainty for blood pressure and very low certainty for cardiovascular morbidity and mortality. Rigorously designed RCTs that carry out longer follow-up and address patient-important outcomes remain warranted. Trial registration: PROSPERO Registration number: CRD42018095854

    Efficient perovskite solar cells by metal ion doping

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    Realizing the theoretical limiting power conversion efficiency (PCE) in perovskite solar cells requires a better understanding and control over the fundamental loss processes occurring in the bulk of the perovskite layer and at the internal semiconductor interfaces in devices. One of the main challenges is to eliminate the presence of charge recombination centres throughout the film which have been observed to be most densely located at regions near the grain boundaries. Here, we introduce aluminium acetylacetonate to the perovskite precursor solution, which improves the crystal quality by reducing the microstrain in the polycrystalline film. At the same time, we achieve a reduction in the non-radiative recombination rate, a remarkable improvement in the photoluminescence quantum efficiency (PLQE) and a reduction in the electronic disorder deduced from an Urbach energy of only 12.6 meV in complete devices. As a result, we demonstrate a PCE of 19.1% with negligible hysteresis in planar heterojunction solar cells comprising all organic p and n-type charge collection layers. Our work shows that an additional level of control of perovskite thin film quality is possible via impurity cation doping, and further demonstrates the continuing importance of improving the electronic quality of the perovskite absorber and the nature of the heterojunctions to further improve the solar cell performance

    Merlin controls the repair capacity of Schwann cells after injury by regulating Hippo/YAP activity

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    Loss of the Merlin tumor suppressor and activation of the Hippo signaling pathway play major roles in the control of cell proliferation and tumorigenesis. We have identified completely novel roles for Merlin and the Hippo pathway effector Yes-associated protein (YAP) in the control of Schwann cell (SC) plasticity and peripheral nerve repair after injury. Injury to the peripheral nervous system (PNS) causes a dramatic shift in SC molecular phenotype and the generation of repair-competent SCs, which direct functional repair. We find that loss of Merlin in these cells causes a catastrophic failure of axonal regeneration and remyelination in the PNS. This effect is mediated by activation of YAP expression in Merlin-null SCs, and loss of YAP restores axonal regrowth and functional repair. This work identifies new mechanisms that control the regenerative potential of SCs and gives new insight into understanding the correct control of functional nerve repair in the PNS

    The Outcome of Phagocytic Cell Division with Infectious Cargo Depends on Single Phagosome Formation

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    Given that macrophages can proliferate and that certain microbes survive inside phagocytic cells, the question arises as to the post-mitotic distribution of microbial cargo. Using macrophage-like cells we evaluated the post-mitotic distribution of intracellular Cryptococcus yeasts and polystyrene beads by comparing experimental data to a stochastic model. For beads, the post-mitotic distribution was that expected from chance alone. However, for yeast cells the post-mitotic distribution was unequal, implying preferential sorting to one daughter cell. This mechanism for unequal distribution was phagosomal fusion, which effectively reduced the intracellular particle number. Hence, post-mitotic intracellular particle distribution is stochastic, unless microbial and/or host factors promote unequal distribution into daughter cells. In our system unequal cargo distribution appeared to benefit the microbe by promoting host cell exocytosis. Post-mitotic infectious cargo distribution is a new parameter to consider in the study of intracellular pathogens since it could potentially define the outcome of phagocytic-microbial interactions
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