- Structural Mechanism Underlying TRPV1 Activation by Pungent Compounds in Gingers. [Journal Article]
- BJBr J Pharmacol 2019 Jun 17
- CONCLUSIONS: Mechanistic insights on ginger compound-TRPV1 interactions should help guide pharmaceutic efforts to regulate nociception.
- Highly in-plane anisotropic two-dimensional semiconductors β-AuSe with multiple superior properties: a first-principles investigation. [Journal Article]
- JPJ Phys Condens Matter 2019 Jun 17
- Discovering highly in-plane anisotropic two-dimensional (2D) semiconductors with multiple superior properties (good stability, widely tunable bandgap and high mobility) are of great interest for fund…
Discovering highly in-plane anisotropic two-dimensional (2D) semiconductors with multiple superior properties (good stability, widely tunable bandgap and high mobility) are of great interest for fundamental studies and for developments of novel (opto)electronic devices. By means of state-of-the-art first-principles calculations, herein we present a thorough investigation on the stability, electronic properties and promising applications of previously unexplored 2D semiconductors -- gold-selenium (β-AuSe) with strong in-plane anisotropy, whose layered bulk counterpart was synthesized fifty years ago. We show that they have stable structures, widely tunable bandgap varying from 1.66 eV in monolayer to 0.70 eV in five-layer, strong light absorption coefficient (~10<sup>5</sup> cm<sup>-1</sup>) within the whole visible light range, and high/ultrahigh carrier mobility (10<sup>3</sup>-10<sup>5</sup> cm<sup>2</sup>V<sup>-1</sup>s<sup>-1</sup>). More importantly, they show highly in-pane anisotropic behaviors in absorption coefficients, photoconductance and carrier mobility. Especially, the anisotropic ratio of carrier mobility is much higher than the literature reported ones. The above findings show that the in-plane anisotropic 2D β-AuSe are promising candidates for developing polarization-sensitive photodetectors, synaptic devices and micro digital inverters based on multiple superior properties and highly anisotropic behaviors. Besides, few-layer β-AuSe systems can serve as channel materials in field-effect transistors with high mobility or be applied in solar cells with strong light absorption. Our findings demonstrate that few-layer 2D β-AuSe have great potential for multifunctional applications and thus stimulate immediately experimental interests.
- Mid-infrared spectroscopy tracing of channel erosion in highly erosive catchments on the Chinese Loess Plateau. [Journal Article]
- STSci Total Environ 2019 Jun 08; 687:309-318
- Whether channel erosion or topsoil erosion constitutes the dominant erosion process throughout in the hilly region of the Chinese Loess Plateau (CLP), which suffers perhaps the most severe soil erosi…
Whether channel erosion or topsoil erosion constitutes the dominant erosion process throughout in the hilly region of the Chinese Loess Plateau (CLP), which suffers perhaps the most severe soil erosion in the world, had been controversial for a long time. The present article attempts to use the mid-infrared (MIR) spectroscopy fingerprinting method to trace sediment sources within nine small catchments in the hilly region of the CLP. Two major categories of sediment sources are identified: channel sediment and topsoil. Sediments trapped by check dams are used as the final sediment transferred by soil erosion. Discriminant analysis shows that MIR spectroscopy can differentiate between the two kinds of source sediments very well. The contributions of channel sediment and topsoil to the total final sediment are quantified using partial least squares regression (PLSR) analyses of MIR spectra to compare the trapped sediment samples with experimental models. The results of the root mean square error of calibration, root mean square error of validation and coefficient of determination for 18 models all show that the MIR-PLSR models boast very high prediction abilities in the nine catchments. A comparison between the geochemical fingerprinting method and the MIR spectroscopy method in one catchment reveals that although the two methods agree well on the channel sediment contributions, the two methods produce a significant difference (R2 = 0.4). Overall, the MIR-PLSR results show that channel sediments contribute 19% to 66% of the total sediment with an average of 33 ± 16% in the nine small catchments. Our results indicate that although channel bank sediment is important, topsoil erosion is the predominant process in small dam-controlled catchments on the CLP. Furthermore, the MIR spectroscopy fingerprinting method can provide a useful, non-destructive, rapid and inexpensive tool for tracing sediment sources from different kinds of loess.
- Toward a Model for Activation of Orai Channel. [Journal Article]
- IiScience 2019 Jun 01; 16:356-367
- Store-operated calcium release-activated calcium (CRAC) channels mediate a variety of cellular signaling functions. The CRAC channel pore-forming protein, Orai1, is a hexamer arranged with 3-fold sym…
Store-operated calcium release-activated calcium (CRAC) channels mediate a variety of cellular signaling functions. The CRAC channel pore-forming protein, Orai1, is a hexamer arranged with 3-fold symmetry. Despite its importance in moving Ca2+ ions into cells, a detailed mechanistic understanding of Orai1 activation is lacking. Herein, a working model is proposed for the putative open state of Orai from Drosophila melanogaster (dOrai), which involves a "twist-to-open" gating mechanism. The proposed model is supported by energetic, structural, and experimental evidence. Fluorescent imaging demonstrates that each subunit on the intracellular side of the pore is inherently strongly cross-linked, which is important for coupling to STIM1, the pore activator, and graded activation of the Orai1 channel. The proposed model thus paves the way for understanding key aspects of calcium signaling at a molecular level.
- Are wall thickness channels defined by computed tomography predictive of isthmuses of post-infarction ventricular tachycardia? [Journal Article]
- HRHeart Rhythm 2019 Jun 14
- CONCLUSIONS: VT-isthmuses were always found in CT-channels (100% sensitivity), and half of CT-channels hosted VT-isthmuses (PPV 51%). Longer and thinner (but >1mm) CT-channels were significantly associated with VT-isthmuses.
- The acute effects of hydrocortisone on cardiac electrocardiography, action potentials, intracellular calcium, and contraction: The role of protein kinase C. [Journal Article]
- MCMol Cell Endocrinol 2019 Jun 14; :110488
- Hydrocortisone exerts adverse effects on various organs, including the heart. This study investigated the still unclear effects of hydrocortisone on electrophysiological and biochemical aspects of ca…
Hydrocortisone exerts adverse effects on various organs, including the heart. This study investigated the still unclear effects of hydrocortisone on electrophysiological and biochemical aspects of cardiac excitation-contraction coupling. In guinea pigs' hearts, hydrocortisone administration reduced the QT interval of ECG and the action potential duration (APD). In guinea pig ventricular myocytes, hydrocortisone reduced contraction and Ca2+ transient amplitudes. These reductions and the effects on APD were prevented by pretreatment with the protein kinase C (PKC) inhibitor staurosporine. In an overexpression system of Xenopus oocytes, hydrocortisone increased hERG K+ currents and reduced Kv1.5 K+ currents; these effects were negated by pretreatment with staurosporine. Western blot analysis revealed dose- and time-dependent changes in PKCα/βII, PKCε, and PKCγ phosphorylation by hydrocortisone in guinea pig ventricular myocytes. Therefore, hydrocortisone can acutely affect cardiac excitation-contraction coupling, including ion channel activity, APD, ECG, Ca2+ transients, and contraction, possibly via biochemical changes in PKC.
- Acetaminophen-induced liver injury is mediated by the ion channel TRPV4. [Journal Article]
- FJFASEB J 2019 Jun 17; :fj201802233R
- Overdosing of the analgesic acetaminophen (APAP) is one of the most common causes for acute liver failure in modern countries. Although the exact molecular mechanisms mediating hepatocellular necrosi…
Overdosing of the analgesic acetaminophen (APAP) is one of the most common causes for acute liver failure in modern countries. Although the exact molecular mechanisms mediating hepatocellular necrosis are still elusive, it is preceded by oxidative stress triggered by excessive levels of the metabolite N-acetyl-para-benzoquinone imine (NAPQI). Here, we describe the role of the redox-sensitive transient receptor potential (TRP) ion channel TRP vanilloid 4 (TRPV4) for APAP-induced hepatoxicity. Both pharmacological inhibition and genetic deletion of TRPV4 ameliorate APAP-induced necrosis in mouse and human hepatocytes in vitro. Liver injury caused by a systemic overdose of APAP is reduced in TRPV4-deficient mice and in wild-type mice treated with a TRPV4 inhibitor. The reduction of hepatotoxicity accomplished by systemic TRPV4 inhibition is comparable to the protective effects of the antioxidant N-acetyl-cysteine. Although TRPV4 does not modulate intrahepatic levels of glutathione, both its inhibition and genetic deletion attenuate APAP-induced oxidative and nitrosative stress as well as mitochondrial membrane depolarization. NAPQI evokes a calcium influx by activating heterologously expressed TRPV4 channels and endogenous TRPV4 channels in hepatoma cells but not in primary mouse hepatocytes. Taken together, our data suggest that TRPV4 mediates APAP-induced hepatotoxicity and thus may be a suitable target for treatment of this critical side effect.-Echtermeyer, F., Eberhardt, M., Risser, L., Herzog, C., Gueler, F., Khalil, M., Engel, M., Vondran, F., Leffler, A. Acetaminophen-induced liver injury is mediated by the ion channel TRPV4.
- Feasibility of Virtual Reality Combined with Isocentric Navigation in Transforaminal Percutaneous Endoscopic Discectomy: A Cadaver Study. [Journal Article]
- OSOrthop Surg 2019 Jun 17
- CONCLUSIONS: Virtual reality combined with isocentric navigation is feasible in TPED. It enables precise surgical planning and improves intraoperative procedures, and has the potential for application in clinical practice.
- Targeting the Potassium Ion Channel Genes SK and SH, as a Novel Approach for Control of Insect pests: Efficacy and Biosafety. [Journal Article]
- PMPest Manag Sci 2019 Jun 17
- CONCLUSIONS: This study demonstrates the potential of using RNAi targeting neural receptors as a technology for the control of T. castaneum. This article is protected by copyright. All rights reserved.
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- Conservation of the voltage-sensitive sodium channel protein within the Insecta. [Journal Article]
- IMInsect Mol Biol 2019 Jun 17
- The voltage-sensitive sodium channel (VSSC) is essential for the generation and propagation of action potentials. VSSC kinetics can be modified by producing different splice variants. The functionali…
The voltage-sensitive sodium channel (VSSC) is essential for the generation and propagation of action potentials. VSSC kinetics can be modified by producing different splice variants. The functionality of VSSC depends on features such as the voltage-sensors, the selectivity filter and the inactivation loop. Mutations in Vssc conferring resistance to pyrethroid insecticides are known as knockdown resistance (kdr). We analyzed the conservation of VSSC in both a broad scope and a narrow scope by three approaches: 1) Compare conservation of sequences and of differential exon use across orders of the Insecta, 2) determine which kdr mutations were possible with a single nucleotide mutation in nine populations or Aedes aegypti, and 3) examine the individual VSSC variation that exists within a population of Drosophila melanogaster. There is an increasing amount of transcript diversity possible from Diplura towards Diptera. The residues of the voltage-sensors, selectivity filter and inactivation loop are highly conserved. The majority of exon sequences were >88.6% similar. Strain specific differences in codon constraints exist for kdr mutations in nine strains of A. aegypti. Three Vssc mutations were found in one population of D. melanogaster. This study shows that overall Vssc is highly conserved across Insecta and within a population of an insect, but that important differences do exist. This article is protected by copyright. All rights reserved.