2,104 research outputs found

    Spindle oscillations are generated in the dorsal thalamus and modulated by the thalamic reticular nucleus

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    Spindle waves occur during the early stage of slow wave sleep and are thought to arise in the thalamic reticular nucleus (TRN), causing inhibitory postsynaptic potential spindle-like oscillations in the dorsal thalamus that are propagated to the cortex. We have found that thalamocortical neurons exhibit membrane oscillations that have spindle frequencies, consist of excitatory postsynaptic potentials, and co-occur with electroencephalographic spindles. TRN lesioning prolonged oscillations in the medial geniculate body (MGB) and auditory cortex (AC). Injection of GABA~A~ antagonist into the MGB decreased oscillation frequency, while injection of GABA~B~ antagonist increased spindle oscillations in the MGB and cortex. Thus, spindles originate in the dorsal thalamus and TRN inhibitory inputs modulate this process, with fast inhibition facilitating the internal frequency and slow inhibition limiting spindle occurrence

    (R)-7-Bromo-2,3,4,4a-tetra­hydro-1H-xanthen-1-one

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    The title compound, C13H11BrO2, contains a tricyclic ring system with one chiral center which exhibits an R configuration. The crystal structure is devoid of any classical hydrogen bonding

    Three-dimensional sedimentation patterns of two interacting disks in a viscous fluid

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    The sedimentation of two spherical solid objects in a viscous fluid has been extensively investigated and well understood. However, a pair of flat disks (in three dimensions) settling in the fluid shows more complex hydrodynamic behaviors. The present work aims to improve understanding of this phenomenon by performing Direct Numerical Simulations (DNS) and physical experiments. The present results show that the sedimentation processes are significantly influenced by disk shape, characterized by a dimensionless moment of inertia I*, and Reynolds number of the leading disk Re. For the flatter disks with smaller I*, steady falling with enduring contact transits to periodic swinging with intermittent contacts as Re increases. The disks with larger I* tend to fall in a Drafting-Kissing-Tumbling (DKT) mode at low Re and to remain separated at high Re. Based on I* and Re, a phase diagram is created to classify the two-disk falling into ten distinctive patterns. The planar motion or three-dimensional motion of the disks is determined primarily by Re. Turbulent disturbance flows at a high Re contribute to the chaotic three-dimensional rotation of the disks. The chance for the two disks to contact is increased when I* and Re are reduced.Comment: 51 pages, 28 figure

    Hypophosphatemia during continuous veno-venous hemofiltration is associated with mortality in critically ill patients with acute kidney injury

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    INTRODUCTION: The primary aim of this study was to determine whether hypophosphatemia during continuous veno-venous hemofiltration (CVVH) is associated with the global outcome of critically ill patients with acute kidney injury (AKI). METHODS: 760 patients diagnosed with AKI and had received CVVH therapy were retrospectively recruited. Death during the 28-day period and survival at 28 days after initiation of CVVH were used as endpoints. Demographic and clinical data including serum phosphorus levels were recorded along with clinical outcome. Hypophosphatemia was defined according to the colorimetric method as serum phosphorus levels < 0.81 mmol/L (2.5 mg/dL), and severe hypophosphatemia was defined as serum phosphorus levels < 0.32 mmol/L (1 mg/dL). The ratio of CVVH therapy days with hypophosphatemia over total CVVH therapy days was calculated to reflect the persistence of hypophosphatemia. RESULTS: The Cox proportional hazard survival model analysis indicated that the incidence of hypophosphatemia or even severe hypophosphatemia was not associated with 28-day mortality independently (p = 0.700). Further analysis with the sub-cohort of patients who had developed hypophosphatemia during the CVVH therapy period indicated that the mean ratio of CVVH therapy days with hypophosphatemia over total CVVH therapy days was 0.58, and the ratio independently associated with the global outcome. Compared with the patients with low ratio (< 0.58), those with high ratio (≥ 0.58) conferred a 1.451-fold increase in 28-day mortality rate (95% CI 1.103–1.910, p = 0.008). CONCLUSIONS: Hypophosphatemia during CVVH associated with the global clinical outcome of critically ill patients with AKI. The ratio of CVVH therapy days with hypophosphatemia over total CVVH therapy days was independently associated with the 28-day mortality, and high ratio conferred higher mortality rate

    Genotyping of TRIM5 locus in northern pig-tailed macaques (Macaca leonina), a primate species susceptible to Human Immunodeficiency Virus type 1 infection

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    <p>Abstract</p> <p>Background</p> <p>The pig-tailed macaques are the only Old World monkeys known to be susceptible to human immunodeficiency virus type 1 (HIV-1) infection. We have previously reported that the <it>TRIM5-Cyclophilin A </it>(<it>TRIMCyp</it>) fusion in pig-tailed macaques (<it>Macaca nemestrina</it>) is dysfunctional in restricting HIV-1, which may explain why pig-tailed macaques are susceptible to HIV-1 infection. Similar results have also been reported by other groups. However, according to the current primate taxonomy, the previously reported <it>M. nemestrina </it>are further classified into three species, which all belong to the <it>Macaca spp</it>. This calls for the need to look into the previous studies in more details.</p> <p>Results</p> <p>The local species Northern pig-tailed macaque (<it>M. leonina</it>) was analyzed for the correlation of <it>TRIM5 </it>structure and HIV-1 infection. Eleven <it>M. leonina </it>animals were analyzed, and all of them were found to possess <it>TRIM5-CypA </it>fusion at the <it>TRIM5 </it>locus. The transcripts encoding the dysfunctional <it>TRIM5-CypA </it>should result from the G-to-T mutation in the 3'-splicing site of intron 6. Polymorphism in the putative TRIMCyp recognition domain was observed. The peripheral blood mononuclear cells (PBMCs) of <it>M. leonina </it>were susceptible to HIV-1 infection. Consistent with the previous results, expression of the <it>M. leonina </it>TRIMCyp in HeLa-T4 cells rendered the cells resistant to HIV-2<sub>ROD </sub>but not to SIVmac239 infection.</p> <p>Conclusion</p> <p>The susceptibility of <it>M. leonina </it>to HIV-1 infection is due to the dysfunctional <it>TRIM5-CypA </it>fusion in the <it>TRIM5 </it>locus. This finding should broaden our perspective in developing better HIV/AIDS non-human primate animal models.</p

    Application of Multilabel Learning Using the Relevant Feature for Each Label in Chronic Gastritis Syndrome Diagnosis

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    Background. In Traditional Chinese Medicine (TCM), most of the algorithms are used to solve problems of syndrome diagnosis that only focus on one syndrome, that is, single label learning. However, in clinical practice, patients may simultaneously have more than one syndrome, which has its own symptoms (signs). Methods. We employed a multilabel learning using the relevant feature for each label (REAL) algorithm to construct a syndrome diagnostic model for chronic gastritis (CG) in TCM. REAL combines feature selection methods to select the significant symptoms (signs) of CG. The method was tested on 919 patients using the standard scale. Results. The highest prediction accuracy was achieved when 20 features were selected. The features selected with the information gain were more consistent with the TCM theory. The lowest average accuracy was 54% using multi-label neural networks (BP-MLL), whereas the highest was 82% using REAL for constructing the diagnostic model. For coverage, hamming loss, and ranking loss, the values obtained using the REAL algorithm were the lowest at 0.160, 0.142, and 0.177, respectively. Conclusion. REAL extracts the relevant symptoms (signs) for each syndrome and improves its recognition accuracy. Moreover, the studies will provide a reference for constructing syndrome diagnostic models and guide clinical practice
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