978 research outputs found

    Enhanced surface acoustic wave cell sorting by 3D microfluidic chip design

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    We demonstrate an acoustic wave driven microfluidic cell sorter that combines advantages of multilayer device fabrication with planar surface acoustic wave excitation. We harness the strong vertical component of the refracted acoustic wave to enhance cell actuation by using an asymmetric flow field to increase cell deflection. Precise control of the 3-dimensional flow is realized by topographical structures implemented on the top of the microchannel. We experimentally quantify the effect of the structure dimensions and acoustic parameter. The design attains cell sorting rates and purities approaching those of state of the art fluorescence-activated cell sorters with all the advantages of microfluidic cell sorting

    Descriptive Study of Prescriptions for Opioids from a Suburban Academic Emergency Department before New York\u27s I-STOP Act.

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    Introduction: Controlled prescription opioid use is perceived as a national problem attributed to all specialties. Our objective was to provide a descriptive analysis of prescriptions written for controlled opioids from a database of emergency department (ED) visits prior to the enactment of the I-STOP law, which requires New York prescribers to consult the Prescription Monitoring Program (PMP) prior to prescribing Schedule II, III, and IV controlled substances for prescriptions of greater than five days duration. Methods: We conducted a retrospective medical record review of patients 21 years of age and older, who presented to the ED between July 1, 2011 – June 30, 2012 and were given a prescription for a controlled opioid. Our primary purpose was to characterize each prescription as to the type of controlled substance, the quantity dispensed, and the duration of the prescription. We also looked at outliers, those patients who received prescriptions for longer than five days. Results: A total of 9,502 prescriptions were written for opioids out of a total 63,143 prescriptions for 69,500 adult patients. Twenty-six (0.27%) of the prescriptions for controlled opioids were written for greater than five days. Most prescriptions were for five days or less (99.7%, 95% CI [99.6 to 99.8%]). Conclusion: The vast majority of opioid prescriptions in our ED prior to the I-STOP legislature were limited to a five-day or less supply. These new regulations were meant to reduce the ED’s contribution to the rise of opioid related morbidity. This study suggests that the emergency physicians’ usual prescribing practices were negligibly limited by the new restrictive regulations. The ED may not be primarily contributing to the increase in opioid-related overdoses and death. The effect of the I-STOP regulation on future prescribing patterns in the ED remains to be determined

    Coexistence of charge density wave and spin-Peierls orders in quarter-filled quasi-one dimensional correlated electron systems

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    Charge and spin-Peierls instabilities in quarter-filled (n=1/2) compounds consisting of coupled ladders and/or zig-zag chains are investigated. Hubbard and t-J models including local Holstein and/or Peierls couplings to the lattice are studied by numerical techniques. Next nearest neighbor hopping and magnetic exchange, and short-range Coulomb interactions are also considered. We show that, generically, these systems undergo instabilities towards the formation of Charge Density Waves, Bond Order Waves and (generalized) spin-Peierls modulated structures. Moderate electron-electron and electron-lattice couplings can lead to a coexistence of these three types of orders. In the ladder, a zig-zag pattern is stabilized by the Holstein coupling and the nearest-neighbor Coulomb repulsion. In the case of an isolated chain, bond-centered and site-centered 2k_F and 4k_F modulations are induced by the local Holstein coupling. In addition, we show that, in contrast to the ladders, a small charge ordering in the chains, strongly enhances the spin-Peierls instability. Our results are applied to the NaV_2O_5 compound (trellis lattice) and various phases with coexisting charge disproportionation and spin-Peierls order are proposed and discussed in the context of recent experiments. The role of the long-range Coulomb potential is also outlined.Comment: 10 pages, Revtex, 10 encapsulated figure

    Influence of the anion potential on the charge ordering in quasi-one dimensional charge transfer salts

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    We examine the various instabilities of quarter-filled strongly correlated electronic chains in the presence of a coupling to the underlying lattice. To mimic the physics of the (TMTTF)2_2X Bechgaard-Fabre salts we also include electrostatic effects of intercalated anions. We show that small displacements of the anion can stabilize new mixed Charged Density Wave-Bond Order Wave phases in which central symmetry centers are suppressed. This finding is discussed in the context of recent experiments. We suggest that the recently observed charge ordering is due to a cooperative effect between the Coulomb interaction and the coupling of the electronic stacks to the anions. On the other hand, the Spin-Peierls instability at lower temperature requires a Peierls-like lattice coupling.Comment: Latex, 4 pages, 4 postscript figure

    Neuroprotective Effects against Glutamate-Induced HT-22 Hippocampal Cell Damage and Caenorhabditis elegans Lifespan/Healthspan Enhancing Activity of Auricularia polytricha Mushroom Extracts.

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    Oxidative stress is associated with several diseases, particularly neurodegenerative diseases, commonly found in the elderly. The attenuation of oxidative status is one of the alternatives for neuroprotection and anti-aging. Auricularia polytricha (AP), an edible mushroom, contains many therapeutic properties, including antioxidant properties. Herein, we report the effects of AP extracts on antioxidant, neuroprotective, and anti-aging activities. The neuroprotective effect of AP extracts against glutamate-induced HT-22 neuronal damage was determined by evaluating the cytotoxicity, intracellular reactive oxygen species (ROS) accumulation, and expression of antioxidant enzyme genes. Lifespan and healthspan assays were performed to examine the effects of AP extracts from Caenorhabditis elegans. We found that ethanolic extract (APE) attenuated glutamate-induced HT-22 cytotoxicity and increased the expression of antioxidant enzyme genes. Moreover, APE promoted in the longevity and health of the C. elegans. Chemical analysis of the extracts revealed that APE contains the highest quantity of flavonoids and a reasonable percentage of phenols. The lipophilic compounds in APE were identified by gas chromatography/mass spectrometry (GC/MS), revealing that APE mainly contains linoleic acid. Interestingly, linoleic acid suppressed neuronal toxicity and ROS accumulation from glutamate induction. These results indicate that AP could be an exciting natural source that may potentially serves as neuroprotective and anti-aging agents

    Mushroom-derived bioactive compounds potentially serve as the inhibitors of SARS-CoV-2 main protease: An in silico approach

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    Background and aim Coronavirus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has now become the world pandemic. There is a race to develop suitable drugs and vaccines for the disease. The anti-HIV protease drugs are currently repurposed for the potential treatment of COVID-19. The drugs were primarily screened against the SARS-CoV-2 main protease. With an urgent need for safe and effective drugs to treat the virus, we have explored natural products isolated from edible and medicinal mushrooms that have been reported to possess anti-HIV protease. Experimental procedures We have examined 36 compounds for their potential to be SARS-CoV-2 main protease inhibitors using molecular docking study. Moreover, drug-likeness properties including absorption, distribution, metabolism, excretion and toxicity were evaluated by in silico ADMET analysis. Results Our AutoDock study showed that 25 of 36 candidate compounds have the potential to inhibit the main viral protease based on their binding affinity against the enzyme’s active site when compared to the standard drugs. Interestingly, ADMET analysis and toxicity prediction revealed that 6 out of 25 compounds are the best drug-like property candidates, including colossolactone VIII, colossolactone E, colossolactone G, ergosterol, heliantriol F and velutin. Conclusion Our study highlights the potential of existing mushroom-derived natural compounds for further investigation and possibly can be used to fight against SARS-CoV-2 infection. Taxonomy (classification by evise) Disease, Infectious Disease, Respiratory System Disease, Covid-19, Traditional Medicine, Traditional Herbal Medicine, Phamaceutical Analysis

    Spectral analysis of Gene co-expression network of Zebrafish

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    We analyze the gene expression data of Zebrafish under the combined framework of complex networks and random matrix theory. The nearest neighbor spacing distribution of the corresponding matrix spectra follows random matrix predictions of Gaussian orthogonal statistics. Based on the eigenvector analysis we can divide the spectra into two parts, first part for which the eigenvector localization properties match with the random matrix theory predictions, and the second part for which they show deviation from the theory and hence are useful to understand the system dependent properties. Spectra with the localized eigenvectors can be characterized into three groups based on the eigenvalues. We explore the position of localized nodes from these different categories. Using an overlap measure, we find that the top contributing nodes in the different groups carry distinguished structural features. Furthermore, the top contributing nodes of the different localized eigenvectors corresponding to the lower eigenvalue regime form different densely connected structure well separated from each other. Preliminary biological interpretation of the genes, associated with the top contributing nodes in the localized eigenvectors, suggests that the genes corresponding to same vector share common features.Comment: 6 pages, four figures (accepted in EPL

    Integrated computational and Drosophila cancer model platform captures previously unappreciated chemicals perturbing a kinase network

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    Drosophila provides an inexpensive and quantitative platform for measuring whole animal drug response. A complementary approach is virtual screening, where chemical libraries can be efficiently screened against protein target(s). Here, we present a unique discovery platform integrating structure-based modeling with Drosophila biology and organic synthesis. We demonstrate this platform by developing chemicals targeting a Drosophila model of Medullary Thyroid Cancer (MTC) characterized by a transformation network activated by oncogenic dRetM955T. Structural models for kinases relevant to MTC were generated for virtual screening to identify unique preliminary hits that suppressed dRetM955T-induced transformation. We then combined features from our hits with those of known inhibitors to create a ‘hybrid’ molecule with improved suppression of dRetM955T transformation. Our platform provides a framework to efficiently explore novel kinase inhibitors outside of explored inhibitor chemical space that are effective in inhibiting cancer networks while minimizing whole body toxicity
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