Journal articles: 'Chemical LTP'

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Hoppanová, Lucia, Veronika Medvecká, Juliana Dylíková, Daniela Hudecová, Barbora Kaliňáková, Svetlana Kryštofová, and Anna Zahoranová. "Low-temperature plasma applications in chemical fungicide treatment reduction." Acta Chimica Slovaca 13, no. 1 (April 1, 2020): 26–33. http://dx.doi.org/10.2478/acs-2020-0005.

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AbstractIn order to reduce the environmental burden of chemicals, various new alternatives to seed protection are being sought. Our aim was to find an environmentally acceptable solution leading to the inactivation of seed-borne phytopathogenic fungi Fusarium culmorum on the surface of wheat and barley seeds with a positive effect on their germination. As a low-temperature plasma (LTP) source, a Diffuse Coplanar Surface Barrier Discharge (DCSBD) was used. Plasma generated by DCSBD is non-equilibrium, cold, diffuse, macroscopically homogeneous even in ambient air at atmospheric pressure. Experimental results showed that LTP treatment in the range of 120—300 s significantly inhibits the growth of F. culmorum on the surface of the seeds. The efficiency of LTP treatment was compared with traditional seed protection processes using chemical fungicide and also with combined seed pretreatment by plasma and subsequent application of chemical fungicide. No growth of F. culmorum was observed after the combination of Vitavax 2000 fungicide application in the dose of 10 % and 60 s of LTP treatment even on the 5th day of incubation. Better wettability of seeds with the chemical fungicide was related to the change on seed surface, which becomes hydrophilic after 10 s of LTP application. Short LTP exposure times did not affect germination and improved the growth parameter of cereal seeds. By combining physical (LTP) and chemical (Vitavax 2000) treatments of cereal seeds, it is possible to effectively reduce the required amount of chemical fungicide and to stimulate germination and early growth seed parameters.

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Ahmad, Faraz, Yu Jing, Albert Lladó, and Ping Liu. "Chemical Stimulation of Rodent and Human Cortical Synaptosomes: Implications in Neurodegeneration." Cells 10, no. 5 (May 12, 2021): 1174. http://dx.doi.org/10.3390/cells10051174.

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Synaptic plasticity events, including long-term potentiation (LTP), are often regarded as correlates of brain functions of memory and cognition. One of the central players in these plasticity-related phenomena is the α-amino-3-hydroxy-5-methylisoxazole-4-propionate receptor (AMPAR). Increased levels of AMPARs on postsynaptic membranes thus constitute a biochemical measure of LTP. Isolated synaptic terminals (synaptosomes) are an excellent ex vivo tool to monitor synaptic physiology in healthy and diseased brains, particularly in human research. We herein describe three protocols for chemically-induced LTP (cLTP) in synaptosomes from both rodent and human brain tissues. Two of these chemical stimulation protocols are described for the first time in synaptosomes. A pharmacological block of synaptosomal actin dynamics confirmed the efficiency of the cLTP protocols. Furthermore, the study prototypically evaluated the deficiency of cLTP in cortical synaptosomes obtained from human cases of early-onset Alzheimer’s disease (EOAD) and frontotemporal lobar degeneration (FLTD), as well as an animal model that mimics FLTD.

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Boccella, Serena, Ida Marabese, Monica Iannotta, Carmela Belardo, Volker Neugebauer, Mariacristina Mazzitelli, Gorizio Pieretti, Sabatino Maione, and Enza Palazzo. "Metabotropic Glutamate Receptor 5 and 8 Modulate the Ameliorative Effect of Ultramicronized Palmitoylethanolamide on Cognitive Decline Associated with Neuropathic Pain." International Journal of Molecular Sciences 20, no. 7 (April 9, 2019): 1757. http://dx.doi.org/10.3390/ijms20071757.

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This study investigated whether metabotropic glutamate receptor (mGluR) 5 and 8 are involved in the effect of ultramicronizedpalmitoylethanolamide (um-PEA) on the cognitive behavior and long term potentiation (LTP) at entorhinal cortex (LEC)-dentate gyrus (DG) pathway in mice rendered neuropathic by the spare nerve injury (SNI). SNI reduced discriminative memory and LTP. Um-PEA treatment started after the development of neuropathic pain had no effects in sham mice, whereas it restored cognitive behavior and LTP in SNI mice. 2-Methyl-6-(phenylethynyl) pyridine (MPEP), a selective mGluR5 antagonist, improved cognition in SNI mice and produced a chemical long term depression of the field excitatory postsynaptic potentials (fEPSPs) in sham and SNI mice. After theta burst stimulation (TBS) MPEP restored LTP in SNI mice. In combination with PEA, MPEP antagonized the PEA effect on discriminative memory and decreased LTP in SNI mice. The (RS)-4-(1-amino-1-carboxyethyl)phthalic acid (MDCPG), a selective mGluR8 antagonist, did not affect discriminative memory, but it induced a chemical LTP and prevented the enhancement of fEPSPs after TBS in SNI mice which were treated or not treated with PEA. The effect of PEA on LTP and cognitive behavior was modulated by mGluR5 and mGluR8. In particular in the SNI conditions, the mGluR5 blockade facilitated memory and LTP, but prevented the beneficial effects of PEA on discriminative memory while the mGluR8 blockade, which was ineffective in itself, prevented the favorable action of the PEA on LTP. Thus, although their opposite roles (excitatory/inhibitory of the two receptor subtypes on the glutamatergic system), they appeared to be required for the neuroprotective effect of PEA in conditions of neuropathic pain.

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Bhalla, Upinder S. "Multiscale interactions between chemical and electric signaling in LTP induction, LTP reversal and dendritic excitability." Neural Networks 24, no. 9 (November 2011): 943–49. http://dx.doi.org/10.1016/j.neunet.2011.05.001.

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Zhang, Lin, Xu Zhao, Yabin Zhao, Fujian Xu, Jinglin Kong, Zhian Hu, Mingying Ma, Sichun Zhang, and Xinrong Zhang. "Rapid analysis of chemical warfare agents by metal needle-enhanced low-temperature plasma mass spectrometry." Analytical Methods 11, no. 29 (2019): 3721–26. http://dx.doi.org/10.1039/c9ay00886a.

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KAN, C. W., C. W. M. YUEN, C. K. CHAN, and M. P. LAU. "EFFECT OF SURFACE TREATMENT ON THE PROPERTIES OF WOOL FABRIC." Surface Review and Letters 14, no. 04 (August 2007): 559–63. http://dx.doi.org/10.1142/s0218625x07009840.

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Wool fiber is commonly used in textile industry, however, it has some technical problems which affect the quality and performance of the finished products such as felting shrinkage, handle, lustre, pilling, and dyeability. These problems may be attributed mainly in the presence of wool scales on the fiber surface. Recently, chemical treatments such as oxidation and reduction are the commonly used descaling methods in the industry. However, as a result of the pollution caused by various chemical treatments, physical treatment such as low temperature plasma (LTP) treatment has been introduced recently because it is similarly capable of achieving a comparable descaling effect. Most of the discussions on the applications of LTP treatment on wool fiber were focused on applying this technique for improving the surface wettability and shrink resistance. Meanwhile, little discussion has been made on the mechanical properties, thermal properties, and the air permeability. In this paper, wool fabric was treated with LTP treatment with the use of a non-polymerizing gas, namely oxygen. After the LTP treatment, the fabrics low-stress mechanical properties, air permeability, and thermal properties were evaluated and discussed.

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Li, Wei, Xin Xu, and Lucas Pozzo-Miller. "Excitatory synapses are stronger in the hippocampus of Rett syndrome mice due to altered synaptic trafficking of AMPA-type glutamate receptors." Proceedings of the National Academy of Sciences 113, no. 11 (February 29, 2016): E1575—E1584. http://dx.doi.org/10.1073/pnas.1517244113.

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Deficits in long-term potentiation (LTP) at central excitatory synapses are thought to contribute to cognitive impairments in neurodevelopmental disorders associated with intellectual disability and autism. Using the methyl-CpG-binding protein 2 (Mecp2) knockout (KO) mouse model of Rett syndrome, we show that naïve excitatory synapses onto hippocampal pyramidal neurons of symptomatic mice have all of the hallmarks of potentiated synapses. Stronger Mecp2 KO synapses failed to undergo LTP after either theta-burst afferent stimulation or pairing afferent stimulation with postsynaptic depolarization. On the other hand, basal synaptic strength and LTP were not affected in slices from younger presymptomatic Mecp2 KO mice. Furthermore, spine synapses in pyramidal neurons from symptomatic Mecp2 KO are larger and do not grow in size or incorporate GluA1 subunits after electrical or chemical LTP. Our data suggest that LTP is occluded in Mecp2 KO mice by already potentiated synapses. The higher surface levels of GluA1-containing receptors are consistent with altered expression levels of proteins involved in AMPA receptor trafficking, suggesting previously unidentified targets for therapeutic intervention for Rett syndrome and other MECP2-related disorders.

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Yang, Shao-Nian, Yun-Gui Tang, and Robert S. Zucker. "Selective Induction of LTP and LTD by Postsynaptic [Ca2+]i Elevation." Journal of Neurophysiology 81, no. 2 (February 1, 1999): 781–87. http://dx.doi.org/10.1152/jn.1999.81.2.781.

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Selective Induction of LTP and LTD by Postsynaptic [Ca2+]i Elevation. Long-term potentiation (LTP) and long-term depression (LTD), two prominent forms of synaptic plasticity at glutamatergic afferents to CA1 hippocampal pyramidal cells, are both triggered by the elevation of postsynaptic intracellular calcium concentration ([Ca2+]i). To understand how one signaling molecule can be responsible for triggering two opposing forms of synaptic modulation, different postsynaptic [Ca2+]i elevation patterns were generated by a new caged calcium compound nitrophenyl-ethylene glycol-bis(β-aminoethyl ether)- N, N, N′, N′-tetraacetic acid in CA1 pyramidal cells. We found that specific patterns of [Ca2+]i elevation selectively activate LTP or LTD. In particular, only LTP was triggered by a brief increase of [Ca2+]i with relatively high magnitude, which mimics the [Ca2+]i rise during electrical stimulation typically used to induce LTP. In contrast, a prolonged modest rise of [Ca2+]i reliably induced LTD. An important implication of the results is that both the amplitude and the duration of an intracellular chemical signal can carry significant biological information.

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Ngamsomrit, S., T. Eknapakul, S. Pinitsoontorn, and P. Songsiriritthigul. "Effect of Mn grinding time on structural, chemical, and magnetic properties of the Manganese Bismuth prepared by sintering in vacuum." Journal of Physics: Conference Series 2431, no. 1 (January 1, 2023): 012060. http://dx.doi.org/10.1088/1742-6596/2431/1/012060.

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Abstract This work reports the changes in structural, chemical, and magnetic properties of the low-temperature phase manganese bismuth (LTP-MnBi) sintered from mixtures of Bi and Mn ball-milled for different times. The milling time was varied from 1 to 15 hr to produce Mn powder with different particle sizes. The average particle size reduced from ~400 µm (original size) to 35 ± 5 µm and 6 ± 2 µm after 1 and 15 hr milling times, respectively. The LTP-MnBi powder was sintered at 275 °C at vacuum pressure below 5 × 10−7 mbar for 12 hours. By increasing the Mn grinding time, the maximum energy product ((BH)max) of LTP-MnBi decreased from 1.98 ± 0.05 to 1.59 ± 0.07 MGOe, and the saturation magnetization (M s) decreased from 53.42 ± 0.90 to 44.32 ± 0.72 emu/g. The x-ray diffraction patterns indicated the reduction of LTP-MnBi content as a function of the milling time, which is agreed with the decrease in the M s value. This is supported by the x-ray photoelectron results, which also showed the increment of Mn oxides on the surface as a function of Mn milling time. The unexpected decrease in M s, which results in a significant reduction of magnetic performance, might be due to the presence of the oxides preventing diffusion during sintering.

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KAN, C. W., C. W. M. YUEN, and S. Q. JIANG. "EFFECT OF SURFACE TREATMENT ON THE ENZYMATIC TREATMENT OF CELLULOSIC FIBER." Surface Review and Letters 14, no. 04 (August 2007): 565–69. http://dx.doi.org/10.1142/s0218625x07009852.

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Fiber modifications by environmentally friendly processing are essential in order to simplify the preparation and finishing processes, in addition to minimizing the chemical waste and associated disposal problem. In this regard, enzymes have been used extensively because it can remove the small fiber ends from yarn surface to create a smooth fabric surface appearance and introduce a degree of softness without using traditional chemical treatment. However, a significant strength reduction and slow reaction rate of the enzymatic reaction limit its industrial application. In this paper, the potential of using low-temperature plasma (LTP) as a surface pre-treatment prior to enzyme treatment on flax fiber has been studied. By means of the LTP pre-treatment, the effectiveness of enzyme treatment can be enhanced.

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Adamovich, I., S. Agarwal, E. Ahedo, L. L. Alves, S. Baalrud, N. Babaeva, A. Bogaerts, et al. "The 2022 Plasma Roadmap: low temperature plasma science and technology." Journal of Physics D: Applied Physics 55, no. 37 (July 5, 2022): 373001. http://dx.doi.org/10.1088/1361-6463/ac5e1c.

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Abstract The 2022 Roadmap is the next update in the series of Plasma Roadmaps published by Journal of Physics D with the intent to identify important outstanding challenges in the field of low-temperature plasma (LTP) physics and technology. The format of the Roadmap is the same as the previous Roadmaps representing the visions of 41 leading experts representing 21 countries and five continents in the various sub-fields of LTP science and technology. In recognition of the evolution in the field, several new topics have been introduced or given more prominence. These new topics and emphasis highlight increased interests in plasma-enabled additive manufacturing, soft materials, electrification of chemical conversions, plasma propulsion, extreme plasma regimes, plasmas in hypersonics, data-driven plasma science and technology and the contribution of LTP to combat COVID-19. In the last few decades, LTP science and technology has made a tremendously positive impact on our society. It is our hope that this roadmap will help continue this excellent track record over the next 5–10 years.

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Machin, Laura, Martin Piontek, Sara Todhe, Katrin Staniek, Lianet Monzote, Werner Fudickar, Torsten Linker, and Lars Gille. "Antileishmanial Anthracene Endoperoxides: Efficacy In Vitro, Mechanisms and Structure-Activity Relationships." Molecules 27, no. 20 (October 13, 2022): 6846. http://dx.doi.org/10.3390/molecules27206846.

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Leishmaniasis is a vector-borne disease caused by protozoal Leishmania parasites. Previous studies have shown that endoperoxides (EP) can selectively kill Leishmania in host cells. Therefore, we studied in this work a set of new anthracene-derived EP (AcEP) together with their non-endoperoxidic analogs in model systems of Leishmania tarentolae promastigotes (LtP) and J774 macrophages for their antileishmanial activity and selectivity. The mechanism of effective compounds was explored by studying their reaction with iron (II) in chemical systems and in Leishmania. The correlation of structural parameters with activity demonstrated that in this compound set, active compounds had a LogPOW larger than 3.5 and a polar surface area smaller than 100 Å2. The most effective compounds (IC50 in LtP < 2 µM) with the highest selectivity (SI > 30) were pyridyl-/tert-butyl-substituted AcEP. Interestingly, also their analogs demonstrated activity and selectivity. In mechanistic studies, it was shown that EP were activated by iron in chemical systems and in LtP due to their EP group. However, the molecular structure beyond the EP group significantly contributed to their differential mitochondrial inhibition in Leishmania. The identified compound pairs are a good starting point for subsequent experiments in pathogenic Leishmania in vitro and in animal models.

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Bencsik, Norbert, Zsófia Szíber, Hanna Liliom, Krisztián Tárnok, Sándor Borbély, Márton Gulyás, Anikó Rátkai, et al. "Protein kinase D promotes plasticity-induced F-actin stabilization in dendritic spines and regulates memory formation." Journal of Cell Biology 210, no. 5 (August 24, 2015): 771–83. http://dx.doi.org/10.1083/jcb.201501114.

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Actin turnover in dendritic spines influences spine development, morphology, and plasticity, with functional consequences on learning and memory formation. In nonneuronal cells, protein kinase D (PKD) has an important role in stabilizing F-actin via multiple molecular pathways. Using in vitro models of neuronal plasticity, such as glycine-induced chemical long-term potentiation (LTP), known to evoke synaptic plasticity, or long-term depolarization block by KCl, leading to homeostatic morphological changes, we show that actin stabilization needed for the enlargement of dendritic spines is dependent on PKD activity. Consequently, impaired PKD functions attenuate activity-dependent changes in hippocampal dendritic spines, including LTP formation, cause morphological alterations in vivo, and have deleterious consequences on spatial memory formation. We thus provide compelling evidence that PKD controls synaptic plasticity and learning by regulating actin stability in dendritic spines.

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Freitas, Lucas Victor Pereira de, Lorena Maria Guimarães Alves, Lázaro Chaves Sicupira, Gevany Paulino de Pinho, and Flaviano Oliveira Silvério. "Determination of DDT in honey samples by liquid–liquid extraction with low-temperature purification (LLE-LTP) combined to HPLC-DAD." Analytical Methods 13, no. 16 (2021): 1955–64. http://dx.doi.org/10.1039/d1ay00264c.

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Hlushchenko, Iryna, and Pirta Hotulainen. "Chemical LTD, but not LTP, induces transient accumulation of gelsolin in dendritic spines." Biological Chemistry 400, no. 9 (August 27, 2019): 1129–39. http://dx.doi.org/10.1515/hsz-2019-0110.

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Abstract Synaptic plasticity underlies central brain functions, such as learning. Ca2+ signaling is involved in both strengthening and weakening of synapses, but it is still unclear how one signal molecule can induce two opposite outcomes. By identifying molecules, which can distinguish between signaling leading to weakening or strengthening, we can improve our understanding of how synaptic plasticity is regulated. Here, we tested gelsolin’s response to the induction of chemical long-term potentiation (cLTP) or long-term depression (cLTD) in cultured rat hippocampal neurons. We show that gelsolin relocates from the dendritic shaft to dendritic spines upon cLTD induction while it did not show any relocalization upon cLTP induction. Dendritic spines are small actin-rich protrusions on dendrites, where LTD/LTP-responsive excitatory synapses are located. We propose that the LTD-induced modest – but relatively long-lasting – elevation of Ca2+ concentration increases the affinity of gelsolin to F-actin. As F-actin is enriched in dendritic spines, it is probable that increased affinity to F-actin induces the relocalization of gelsolin.

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Hlushchenko, Iryna, and Pirta Hotulainen. "Chemical LTD, but not LTP, induces transient accumulation of gelsolin in dendritic spines." IBRO Reports 6 (September 2019): S276. http://dx.doi.org/10.1016/j.ibror.2019.07.858.

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Bastos, Fatima C., Vanessa N. Corceiro, Sandra A. Lopes, José G. de Almeida, Carlos M. Matias, Jose C. Dionisio, Paulo J. Mendes, Fernando D. S. Sampaio dos Aidos, Rosa M. Quinta-Ferreira, and M. Emilia Quinta-Ferreira. "Effect of tolbutamide on tetraethylammonium-induced postsynaptic zinc signals at hippocampal mossy fiber-CA3 synapses." Canadian Journal of Physiology and Pharmacology 95, no. 9 (September 2017): 1058–63. http://dx.doi.org/10.1139/cjpp-2016-0379.

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The application of tetraethylammonium (TEA), a blocker of voltage-dependent potassium channels, can induce long-term potentiation (LTP) in the synaptic systems CA3–CA1 and mossy fiber-CA3 pyramidal cells of the hippocampus. In the mossy fibers, the depolarization evoked by extracellular TEA induces a large amount of glutamate and also of zinc release. It is considered that zinc has a neuromodulatory role at the mossy fiber synapses, which can, at least in part, be due to the activation of presynaptic ATP-dependent potassium (KATP) channels. The aim of this work was to study properties of TEA-induced zinc signals, detected at the mossy fiber region, using the permeant form of the zinc indicator Newport Green. The application of TEA caused a depression of those signals that was partially blocked by the KATP channel inhibitor tolbutamide. After the removal of TEA, the signals usually increased to a level above baseline. These results are in agreement with the idea that intense zinc release during strong synaptic events triggers a negative feedback action. The zinc depression, caused by the LTP-evoking chemical stimulation, turns into potentiation after TEA washout, suggesting the existence of a correspondence between the observed zinc potentiation and TEA-evoked mossy fiber LTP.

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Wang, Hua Qing, and Mei Yang. "Treatment of Wool Fabrics by Argon Atmospheric Pressure Low Temperature Plasma and its Dyeing." Advanced Materials Research 441 (January 2012): 49–53. http://dx.doi.org/10.4028/www.scientific.net/amr.441.49.

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With the increase in the environmental protection consciousness of people, attention has focused on plasma technology because of its efficiency and environmentally friendliness. In order to improve the dyeing behavior of wool fabrics, surface modification of wool fabrics was carried out using an atmospheric pressure (argon) low temperature plasma treatment (LTP). Morphology and chemical composition analyses of the treated wool fiber surface were carried out by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The effect on the surface properties of wool fabrics treated for different times was evaluated. The results showed that the coloration of wool fabric is improved with an argon atmospheric pressure low temperature plasma (LTP) treatment but the fabric has a lower color fastness to washing and rubbing. This results from the formation of sulfonic groups and the increase in nitrogen content attributed to more severe etching and oxidization on the surface of wool fibers.

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Soldatova, AE, AY Tsegelskaya, GK Semenova, TS Kurkin, PV Dmitryakov, SI Belousov, and AA Kuznetsov. "One-pot synthesis of semicrystalline polyamide imide based on 4,4’-diaminobenzanilide and 2,2-propylidene-bis(1,4-phenyleneoxy)diphthalic anhydride in molten benzoic acid." High Performance Polymers 31, no. 1 (January 16, 2018): 63–71. http://dx.doi.org/10.1177/0954008317750891.

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High-temperature thermoplastic semicrystalline polyamide imide (PAI) with Tg = 250°C, and Tm = 370°C was synthesized from 4,4’-diaminobenzanilide, and 2,2-propylidene-bis (1,4-phenyleneoxy) diphthalic anhydride using three different methods: one-pot high-temperature catalytic polycondensation in molten benzoic acid (BA), low-temperature polycondensation (LTP) in dimethylacetamide (DMAA) followed by chemical imidization, and LTP followed by imidization. The influence of the synthetic route on the crystallinity of PAI was studied by wide-angle X-ray scattering. The PAI synthesized in molten BA comprised a reactive oligomer, which on heating up to 360°C easily transformed into high-molecular-weight PAI. The thermal and rheological properties of the high-molecular-weight PAI thus prepared were studied using differential scanning calorimetry, trimellitic acid, thermogravimetric analysis, and capillary viscosimetry. The rheological characteristics indicate that the obtained PAI can be melt processed by extrusion and hot pressing at 370–380°C.

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Kim, Cheol-Hee, Fan Meng, Mizuo Kajino, Jaehyun Lim, Wei Tang, Jong-Jae Lee, Yusuke Kiriyama, et al. "Comparative Numerical Study of PM2.5 in Exit-and-Entrance Areas Associated with Transboundary Transport over China, Japan, and Korea." Atmosphere 12, no. 4 (April 8, 2021): 469. http://dx.doi.org/10.3390/atmos12040469.

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We report the results of year-long PM2.5 (particulate matter less than 2.5 µm in diameter) simulations over Northeast Asia for the base year of 2013 under the framework of the Long-range Transboundary Air Pollutants in Northeast Asia (LTP) project. LTP is a tripartite project launched by China, Japan, and Korea for cooperative monitoring and modeling of the long-range transport (LRT) of air pollutants. In the modeling aspect in the LTP project, each country’s modeling group employs its own original air quality model and options. The three regional air quality models employed by the modeling groups are WRF-CAMx, NHM-RAQM2, and WRF-CMAQ. PM2.5 concentrations were simulated in remote exit-and-entrance areas associated with the LRT process over China, Japan, and Korea. The results showed apparent bias that remains unexplored due to a series of uncertainties from emission estimates and inherent model limitations. The simulated PM10 levels at seven remote exit-and-entrance sites were underestimated with the normalized mean bias of 0.4 ± 0.2. Among the four chemical components of PM2.5 (SO42−, NO3−, organic carbon (OC), and elemental carbon (EC)), the largest inter-model variability was in OC, with the second largest discrepancy in NO3−. Our simulation results also indicated that under considerable SO42− levels, favorable environments for ammonium nitrate formation were found in exit-and-entrance areas between China and Korea, and gas-aerosol partitioning for semi-volatile species of ammonium nitrate could be fully achieved prior to arrival at the entrance areas. Other chemical characteristics, including NO3−/SO42− and OC/EC ratios, are discussed to diagnose the LRT characteristics of PM2.5 in exit-and-entrance areas associated with transboundary transport over China, Japan, and Korea.

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Ansari, Md Hasan Raza, Udaya Mohanan Kannan, and Seongjae Cho. "Core-Shell Dual-Gate Nanowire Charge-Trap Memory for Synaptic Operations for Neuromorphic Applications." Nanomaterials 11, no. 7 (July 7, 2021): 1773. http://dx.doi.org/10.3390/nano11071773.

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This work showcases the physical insights of a core-shell dual-gate (CSDG) nanowire transistor as an artificial synaptic device with short/long-term potentiation and long-term depression (LTD) operation. Short-term potentiation (STP) is a temporary potentiation of a neural network, and it can be transformed into long-term potentiation (LTP) through repetitive stimulus. In this work, floating body effects and charge trapping are utilized to show the transition from STP to LTP while de-trapping the holes from the nitride layer shows the LTD operation. Furthermore, linearity and symmetry in conductance are achieved through optimal device design and biases. In a system-level simulation, with CSDG nanowire transistor a recognition accuracy of up to 92.28% is obtained in the Modified National Institute of Standards and Technology (MNIST) pattern recognition task. Complementary metal-oxide-semiconductor (CMOS) compatibility and high recognition accuracy makes the CSDG nanowire transistor a promising candidate for the implementation of neuromorphic hardware.

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Kan, C. W., C. W. M. Yuen, W. Y. Tsoi, and C. K. Chan. "Ink-jet printing for Plasma-treated Cotton Fabric with Biomaterial." ASEAN Journal of Chemical Engineering 11, no. 1 (August 5, 2011): 1. http://dx.doi.org/10.22146/ajche.50037.

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Currently, sodium alginate is commonly used for preparing the printing medium for digital ink-jet printing due to its ready solubility and excellent stability even at high-temperature fixation treatments. Similar to sodium alginate, chitosan is also widely used as novel biomaterial. As a natural polymer, sodium alginate and chitosan are biocompatible, biodegradable and non-toxic. Therefore, chitosan may be used as a chemical for preparing printing medium for digital ink-jet printing for cotton fabric. Recently, low temperature plasma (LTP) treatment has proved to be an effective pretreatment method for the improving coating process by altering the surface properties of the material without much changing of the bulk properties. Thus, the aim of this study was to investigate the possibility of applying LTP treatment as pretreatment process to enhance the coating of printing medium, i.e. sodium alginate and sodium alginate/chitosan mixture, so as to improve the final properties of the digital ink-jet printed cotton fabric.

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Ron, Izhar, Hagay Sharabi, Amalia Zaltsman, Amir Leibman, Mordi Hotoveli, Alexander Pevzner, and Shai Kendler. "Non-Contact, Continuous Sampling of Porous Surfaces for the Detection of Particulate and Adsorbed Organic Contaminations by Low-Temperature Plasma Coupled to Ion Mobility Spectrometer." Sensors 23, no. 4 (February 17, 2023): 2253. http://dx.doi.org/10.3390/s23042253.

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Chemical analysis of hazardous surface contaminations, such as hazardous substances, explosives or illicit drugs, is an essential task in security, environmental and safety applications. This task is mostly based on the collection of particles with swabs, followed by thermal desorption into a vapor analyzer, usually a detector based on ion mobility spectrometry (IMS). While this methodology is well established for several civil applications, such as border control, it is still not efficient enough for various conditions, as in sampling rough and porous surfaces. Additionally, the process of thermal desorption is energetically inefficient, requires bulky hardware and introduces device contamination memory effects. Low-temperature plasma (LTP) has been demonstrated as an ionization and desorption source for sample preparation-free analysis, mostly at the inlet of a mass spectrometer analyzer, and in rare cases in conjunction with an ion mobility spectrometer. Herein, we demonstrate, for the first time, the operation of a simple, low cost, home-built LTP apparatus for desorbing non-volatile analytes from various porous surfaces into the inlet of a handheld IMS vapor analyzer. We show ion mobility spectra that originate from operating the LTP jet on porous surfaces such as asphalt and shoes, contaminated with model amine-containing organic compounds. The spectra are in good correlation with spectra measured for thermally desorbed species. We verify through LC-MS analysis of the collected vapors that the sampled species are not fragmented, and can thus be identified by commercial IMS detectors.

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Wang, Yong, Weidong Yu, and Weidong Yu. "Surface Characterization of Low Temperature Plasma-Induced Cashmere Fibre by Air Gas." Fibres and Textiles in Eastern Europe 25 (October 31, 2017): 37–41. http://dx.doi.org/10.5604/01.3001.0010.4625.

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Low temperature plasma (LTP) processing technology was successfully applied to modify cashmere fibres and three kinds of assemblies were formed, i.e., weak-treated, optimised -treated and severe-treated ones. Treatment parameters were optimised in terms of the tensile behaviour, friction effect, wettability and touch feeling of cashmere without major modification of the properties inside the fibre. Detailed characterisation was performed to investigate the surface morphologies and chemical compositions of plasma-induced fibres. SEM demonstrates different minor etching effects of the treated cashmere fibres. XPS results indicate a significant increase in surface concentrations of O and N, and an obvious decrease in C after different LTP treatments as a whole. The C-H/C-C non-polar bonds were reduced and C-O/C-N, C = O polar groups were remarkably increased on the cashmere surface after plasma modification. In addition, a carboxyl group (O-C = O) formed. It is found that oxygen-containing bonds, namely, C-O/C-N, C = O and O-C = O, are responsible for the hydrophilic properties of cashmere.

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Matt, Lucas, Thomas Pham, David Skrabak, Felix Hoffmann, Philipp Eckert, Jiaqi Yin, Miriam Gisevius, et al. "The Na+-activated K+ channel Slack contributes to synaptic development and plasticity." Cellular and Molecular Life Sciences 78, no. 23 (October 18, 2021): 7569–87. http://dx.doi.org/10.1007/s00018-021-03953-0.

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AbstractHuman mutations of the Na+-activated K+ channel Slack (KCNT1) are associated with epilepsy and intellectual disability. Accordingly, Slack knockout mice (Slack−/−) exhibit cognitive flexibility deficits in distinct behavioral tasks. So far, however, the underlying causes as well as the role of Slack in hippocampus-dependent memory functions remain enigmatic. We now report that infant (P6–P14) Slack−/− lack both hippocampal LTD and LTP, likely due to impaired NMDA receptor (NMDAR) signaling. Postsynaptic GluN2B levels are reduced in infant Slack−/−, evidenced by lower amplitudes of NMDAR-meditated excitatory postsynaptic potentials. Low GluN2B affected NMDAR-mediated Ca2+-influx, rendering cultured hippocampal Slack−/−neurons highly insensitive to the GluN2B-specific inhibitor Ro 25-6981. Furthermore, dephosphorylation of the AMPA receptor (AMPAR) subunit GluA1 at S845, which is involved in AMPAR endocytosis during homeostatic and neuromodulator-regulated plasticity, is reduced after chemical LTD (cLTD) in infant Slack−/−. We additionally detect a lack of mGluR-induced LTD in infant Slack−/−, possibly caused by upregulation of the recycling endosome-associated small GTPase Rab4 which might accelerate AMPAR recycling from early endosomes. Interestingly, LTP and mGluR LTD, but not LTD and S845 dephosphorylation after cLTD are restored in adult Slack−/−. This together with normalized expression levels of GluN2B and Rab4 hints to developmental “restoration” of LTP expression despite Slack ablation, whereas in infant and adult brain, NMDAR-dependent LTD induction depends on this channel. Based on the present findings, NMDAR and vesicular transport might represent novel targets for the therapy of intellectual disability associated with Slack mutations. Consequently, careful modulation of hippocampal Slack activity should also improve learning abilities.

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Bonzanini, Angelo D., Ketong Shao, David B. Graves, Satoshi Hamaguchi, and Ali Mesbah. "Foundations of machine learning for low-temperature plasmas: methods and case studies." Plasma Sources Science and Technology 32, no. 2 (February 1, 2023): 024003. http://dx.doi.org/10.1088/1361-6595/acb28c.

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Abstract Machine learning (ML) and artificial intelligence have proven to be an invaluable tool in tackling a vast array of scientific, engineering, and societal problems. The main drivers behind the recent proliferation of ML in practically all aspects of science and technology can be attributed to: (a) improved data acquisition and inexpensive data storage; (b) exponential growth in computing power; and (c) availability of open-source software and resources that have made the use of state-of-the-art ML algorithms widely accessible. The impact of ML on the field of low-temperature plasmas (LTPs) could be particularly significant in the emerging applications that involve plasma treatment of complex interfaces in areas ranging from the manufacture of microelectronics and processing of quantum materials, to the LTP-driven electrification of the chemical industry, and to medicine and biotechnology. This is primarily due to the complex and poorly-understood nature of the plasma-surface interactions in these applications that pose unique challenges to the modeling, diagnostics, and predictive control of LTPs. As the use of ML is becoming more prevalent, it is increasingly paramount for the LTP community to be able to critically analyze and assess the concepts and techniques behind data-driven approaches. To this end, the goal of this paper is to provide a tutorial overview of some of the widely-used ML methods that can be useful, amongst others, for discovering and correlating patterns in the data that may be otherwise impractical to decipher by human intuition alone, for learning multivariable nonlinear data-driven prediction models that are capable of describing the complex behavior of plasma interacting with interfaces, and for guiding the design of experiments to explore the parameter space of plasma-assisted processes in a systematic and resource-efficient manner. We illustrate the utility of various supervised, unsupervised and active learning methods using LTP datasets consisting of commonly-available, information-rich measurements (e.g. optical emission spectra, current–voltage characteristics, scanning electron microscope images, infrared surface temperature measurements, Fourier transform infrared spectra). All the ML demonstrations presented in this paper are carried out using open-source software; the datasets and codes are made publicly available. The FAIR guiding principles for scientific data management and stewardship can accelerate the adoption and development of ML in the LTP community.

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Wang, Huaiqing, Hongzhang Zhang, Yi Cheng, Kai Feng, Xianfeng Li, and Huamin Zhang. "All-NASICON LVP-LTP aqueous lithium ion battery with excellent stability and low-temperature performance." Electrochimica Acta 278 (July 2018): 279–89. http://dx.doi.org/10.1016/j.electacta.2018.05.047.

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Nelissen, Ellis, Elentina K. Argyrousi, Nick P. Van Goethem, Fuqiang Zhao, Catherine D. G. Hines, Gayathri Swaminath, Michael Gerisch, Joerg Hueser, Peter Sandner, and Jos Prickaerts. "Soluble Guanylate Cyclase Stimulator Vericiguat Enhances Long-Term Memory in Rats without Altering Cerebral Blood Volume." Biomedicines 9, no. 8 (August 19, 2021): 1047. http://dx.doi.org/10.3390/biomedicines9081047.

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Vascular cognitive impairment (VCI) is characterized by impairments in cerebral blood flow (CBF), endothelial function and blood–brain barrier (BBB) integrity. These processes are all physiologically regulated by the nitric oxide (NO)-soluble guanylate cyclase (sGC)-cGMP signaling pathway. Additionally, cGMP signaling plays an important role in long-term potentiation (LTP) underlying memory formation. Therefore, targeting the NO-sGC-cGMP pathway may be a therapeutic strategy for treating VCI. Hence, in this study we investigated whether sGC stimulator vericiguat has potential as a cognitive enhancer. The effects of vericiguat on long-term memory were measured in rats using an object location task. Due to the low brain-penetrance of vericiguat found in this study, it was investigated whether in the absence of BBB limitations, vericiguat enhanced hippocampal plasticity using an ex vivo memory acquisition-like chemical LTP model. Finally, peripheral effects were measured by means of blood pressure and cerebral blood volume. Vericiguat successfully enhanced long-term memory and increased hippocampal plasticity via enhanced translocation of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors to the cell membrane, while blood pressure and cerebral blood volume were unaltered. Although the memory enhancing effects in this study are likely due to peripheral effects on the cerebral microvasculature, sGC stimulation may provide a new therapeutic strategy for treating VCI, especially when BBB integrity is reduced.

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Kastian, Ria Fajarwati, Takunori Minegishi, and Naoyuki Inagaki. "Simultaneous analyses of clutch coupling and actin polymerization in dendritic spines of rodent hippocampal neurons during chemical LTP." STAR Protocols 2, no. 4 (December 2021): 100904. http://dx.doi.org/10.1016/j.xpro.2021.100904.

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Zhang, Bin, Wen Lu, Wu Ma, Fusheng Xue, Yongchao Zhang, and Weiqing Fang. "Differential phosphorylation modulation of GluN2B at tyrosine 1336 in two types of chemical‐induced LTP in hippocampal slices." FASEB Journal 34, S1 (April 2020): 1. http://dx.doi.org/10.1096/fasebj.2020.34.s1.03902.

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Chin, Pui Mun, Aine Nazira Naim, Fatihah Suja, and Muhammad Fadly Ahmad Usul. "Impact of Effluent from the Leachate Treatment Plant of Taman Beringin Solid Waste Transfer Station on the Quality of Jinjang River." Processes 8, no. 12 (November 27, 2020): 1553. http://dx.doi.org/10.3390/pr8121553.

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Rapid population growth has contributed to increased solid waste generated in Malaysia. Most landfills that have reached the design capacity are now facing closure. Taman Beringin Landfill was officially closed, so the Taman Beringin Solid Waste Transfer Station was built to manage the relocation, consolidation, and transportation of solid waste to Bukit Tagar Sanitary Landfill. Leachates are generated as a consequence of rainwater percolation through waste and biochemical processes in waste cells. Leachate treatment is needed, as leachates cause environmental pollution and harm human health. This study investigates the impact of treated leachate discharge from a Leachate Treatment Plant (LTP) on the Jinjang River water quality. The performance of the LTP in Taman Beringin Solid Waste Transfer Station was also assessed. Leachate samples were taken at the LTP’s anoxic tank, aeration tank, secondary clarifier tank, and final discharge point, whereas river water samples were taken upstream and downstream of Jinjang River. The untreated leachate returned the following readings: biochemical oxygen demand (BOD) (697.50 ± 127.94 mg/L), chemical oxygen demand (COD) (2419.75 ± 1155.22 mg/L), total suspended solid (TSS) (2710.00 ± 334.79 mg/L), and ammonia (317.08 ± 35.45 mg/L). The LTP’s overall performance was satisfactory, as the final treated leachates were able to meet the standard requirements of the Environmental Quality (Control of Pollution from Solid Waste Transfer Station and Landfill) Regulation 2009. However, the LTP’s activated sludge system performance was not satisfactory, and the parameters did not meet the standard limits. The result shows a low functioning biological treatment method that could not efficiently treat the leachate. However, a subsequent step of combining the biological and chemical process (coagulation, flocculation, activated sludge system, and activated carbon adsorption) helped the treated leachate to meet the standard B requirement stipulated by the Department of Environment (DOE), i.e., to flow safely into the river. This study categorized Jinjang River as polluted, with the discharge of the LTP’s treated leachates, possibly contributing to the river pollution. However, other factors, such as the upstream sewage treatment plant and the ex-landfill downstream, may have also affected the river water quality. The LTP’s activated sludge system performance at the transfer station still requires improvement to reduce the cost of the chemical treatment.

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Santschi, Linda, Magali Reyes-Harde, and Patric K. Stanton. "Chemically Induced, Activity-Independent LTD Elicited by Simultaneous Activation of PKG and Inhibition of PKA." Journal of Neurophysiology 82, no. 3 (September 1, 1999): 1577–89. http://dx.doi.org/10.1152/jn.1999.82.3.1577.

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Although it is widely agreed that cyclic AMP is necessary for the full expression of long-term potentiation of synaptic strength, it is unclear whether cyclic AMP or cyclic AMP-dependent protein kinase (PKA) play roles in the induction of long-term depression (LTD). We show here that two PKA inhibitors, H-89 (10 μM) and KT5720 (1 μM), are unable to block induction of LTD at Schaffer collateral-CA1 synapses in hippocampal slices in vitro. Rather, H-89 enhanced the magnitude of LTD induced by submaximal low-frequency stimulation. Raising [cGMP] with zaprinast (20 μM), a selective type V phosphodiesterase inhibitor, reversibly depressed synaptic potentials. However, coapplication of H-89 plus zaprinast converted this to a robust LTD that depended critically on activation of cyclic GMP-dependent protein kinase (PKG). Chemically induced LTD is activity-independent because it could be induced without stimulation and in tetrodotoxin (0.5 μM). Additionally, chemical LTD did not require activation of N-methyl-d-aspartate or GABA receptors and could be reversed by LTP. Stimulus-induced LTD occluded chemical LTD, suggesting a common expression mechanism. In contrast to bath application, postsynaptic infusion of H-89 into CA1 pyramidal neurons did not enhance LTD, suggesting a presynaptic site of action. Further evidence for a presynaptic locus was supplied by experiments where H-89 applied postsynaptically along with bath application of zaprinast was unable to produce chemical LTD. Thus simultaneous presynaptic generation of cyclic GMP and inhibition of PKA is sufficient to induce LTD of synaptic transmission at Schaffer collateral-CA1 synapses.

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Buhler, Sofie, Jaap H. Akkerdaas, Thelma A. Pertinhez, Ronald Van Ree, Arnaldo Dossena, Stefano Sforza, and Tullia Tedeschi. "Development of a strategy for the total chemical synthesis of an allergenic protein: the peach LTP Pru p 3." Journal of Peptide Science 23, no. 4 (February 10, 2017): 282–93. http://dx.doi.org/10.1002/psc.2981.

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Tian, Jun Ying, and Rui Dong Pang. "The Digital Ink-Jet Printing Properties of Cashmere Treated by Low-Temperature Plasma." Advanced Materials Research 201-203 (February 2011): 2488–91. http://dx.doi.org/10.4028/www.scientific.net/amr.201-203.2488.

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Microwave low temperature plasma（LTP）which is a physical processing method is used to modify the physical and chemical properties of cashmere fiber, thus improve digital printability. The paper mainly studies the effects of low temperature plasmas modification on the scale structure, the change of chemical component, hydrophilicity, printing properties of cashmere. The results show that low temperature plasmas treatment can make cashmere fiber scale edge blunted but keep in the integrity of scale structure. Hydrophilicity of cashmere fiber is improved as lipid substances exposed to the surface of fiber are damaged and yielding hydrophilic groups. In digital printing process, the k/s values of cashmere pretreated by low temperature plasma are higher than untreated ones because of the micro-etching of low temperature plasmas and yielding hydrophilic groups on cashmere surface. Cashmere fiber modified by low temperature plasmas can be steamed at 90°C for 0.5h. The application research of low temperature plasmas to cashmere fiber modification can improve the quality of cashmere products and reduce water and energy consumption.

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Hossen, Emran, Yasuhiro Funahashi, Md Faruk, Rijwan Ahammad, Mutsuki Amano, Kiyofumi Yamada, and Kozo Kaibuchi. "Rho-Kinase/ROCK Phosphorylates PSD-93 Downstream of NMDARs to Orchestrate Synaptic Plasticity." International Journal of Molecular Sciences 24, no. 1 (December 26, 2022): 404. http://dx.doi.org/10.3390/ijms24010404.

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The N-methyl-D-aspartate receptor (NMDAR)-mediated structural plasticity of dendritic spines plays an important role in synaptic transmission in the brain during learning and memory formation. The Rho family of small GTPase RhoA and its downstream effector Rho-kinase/ROCK are considered as one of the major regulators of synaptic plasticity and dendritic spine formation, including long-term potentiation (LTP). However, the mechanism by which Rho-kinase regulates synaptic plasticity is not yet fully understood. Here, we found that Rho-kinase directly phosphorylated discs large MAGUK scaffold protein 2 (DLG2/PSD-93), a major postsynaptic scaffold protein that connects postsynaptic proteins with NMDARs; an ionotropic glutamate receptor, which plays a critical role in synaptic plasticity. Stimulation of striatal slices with an NMDAR agonist induced Rho-kinase-mediated phosphorylation of PSD-93 at Thr612. We also identified PSD-93-interacting proteins, including DLG4 (PSD-95), NMDARs, synaptic Ras GTPase-activating protein 1 (SynGAP1), ADAM metallopeptidase domain 22 (ADAM22), and leucine-rich glioma-inactivated 1 (LGI1), by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Among them, Rho-kinase increased the binding of PSD-93 to PSD-95 and NMDARs. Furthermore, we found that chemical-LTP induced by glycine, which activates NMDARs, increased PSD-93 phosphorylation at Thr612, spine size, and PSD-93 colocalization with PSD-95, while these events were blocked by pretreatment with a Rho-kinase inhibitor. These results indicate that Rho-kinase phosphorylates PSD-93 downstream of NMDARs, and suggest that Rho-kinase mediated phosphorylation of PSD-93 increases the association with PSD-95 and NMDARs to regulate structural synaptic plasticity.

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Fujii, Satoshi, Hiroshi Sasaki, Katsuhiko Mikoshiba, Yoichiro Kuroda, Yoshihiko Yamazaki, Ahmed Mostafa Taufiq, and Hiroshi Kato. "A chemical LTP induced by co-activation of metabotropic and N-methyl-d-aspartate glutamate receptors in hippocampal CA1 neurons." Brain Research 999, no. 1 (February 2004): 20–28. http://dx.doi.org/10.1016/j.brainres.2003.11.058.

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Adamec, Robert. "Modelling Anxiety Disorders Following Chemical Exposures." Toxicology and Industrial Health 10, no. 4-5 (July 1994): 391–420. http://dx.doi.org/10.1177/074823379401000513.

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The effects of kindling and inverse benzodiazepine receptor agonist -carbolines on animal models of anxiety are briefly reviewed in relation to affective disorder associated with chemical exposure. Recent experimental results are described. In the present study, cats were given the inverse benzodiazepine receptor agonist, FG-7142, a powerful anxiogenic compound in humans and animals. Neural transmission in pathways involved in defensive behavior in the cat was monitored using evoked potential techniques. Change in these pathways was related to behavioral changes induced by the drug. It was found that a single dose offG-7142 lastingly increased defensive response to rodents for at least 40 days after drug administration. Behavioral change was specific to defensive response, since approach-attack behavior remained unchanged, replicating previous studies. The benzodiazepine receptor antagonist, Flumazenil, reversed the increase in defensiveness in a drug-dependent manner, replicating previous findings. Increased defensiveness was paralleled by a delayed onset potentiation of neural transmission between the amygdala and the medial hypothalamus of the left hemisphere. Potentiation in the left hemisphere was transient, decaying between 6 and 12 days after the drug. There was a longer lasting potentiation (LTP) of activity evoked in the left and right amygdalo-periacqueductal gray pathways and in the right amygdalo-medial hypothalamic pathway. Potentiation in these pathways appeared at the time of behavioral change. Potentiation of the right amygdalo-periacqueductal gray and right amygdalo-medial hypothalamic pathways persisted until the end of the experiment. In contrast, potentiation of the left amygdalo-periacqueductal gray pathway faded by 40 days after the drug. Flumazenil decreased potentiation only in the right amygdalo-periacqueductal gray pathway. These data strongly suggest that lasting affective change is mediated by lasting changes in particular efferents of the amygdala of the right hemisphere. Behavioral and physiological effects offG-7142 were blocked by the N-methyl-D-Aspartate (NMDA) receptor blocker, AP7. The data suggest that failure of neural inhibition induced by FG-7142 engages NMDA receptor processes to produce lasting potentiation of transmission in neural circuits that mediate defensive response with behavioral consequences. Since FG-7142 interferes with GABA mediated neural inhibition and is proconvulsant, its action might mimic the action of other environmental chemicals with similar properties, such as chlorinated hydrocarbon insecticides. The relationship of the present data to the literature on the neural and behavioral effects of insecticide exposure is discussed. The significance of these findings for multiple chemical sensitivity disorder is also briefly discussed.

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Kang, Wonkyu, Kyoungmin Woo, Hyon Na, Chi Kang, Tae-Sik Yoon, Kyung Kim, and Hyun Lee. "Analog Memristive Characteristics of Square Shaped Lanthanum Oxide Nanoplates Layered Device." Nanomaterials 11, no. 2 (February 9, 2021): 441. http://dx.doi.org/10.3390/nano11020441.

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Square-shaped or rectangular nanoparticles (NPs) of lanthanum oxide (LaOx) were synthesized and layered by convective self-assembly to demonstrate an analog memristive device in this study. Along with non-volatile analog memory effect, selection diode property could be co-existent without any implementation of heterogeneous multiple stacks with ~1 μm thick LaOx NPs layer. Current–voltage (I–V) behavior of the LaOx NPs resistive switching (RS) device has shown an evolved current level with memristive behavior and additional rectification functionality with threshold voltage. The concurrent memristor and diode type selector characteristics were examined with electrical stimuli or spikes for the duration of 10–50 ms pulse biases. The pulsed spike increased current levels at a read voltage of +0.2 V sequentially along with ±7 V biases, which have emulated neuromorphic operation of long-term potentiation (LTP). This study can open a new application of rare-earth LaOx NPs as a component of neuromorphic synaptic device.

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Koltun, Bella, Sivan Ironi, Noga Gershoni-Emek, Iliana Barrera, Mohammad Hleihil, Siddharth Nanguneri, Ranjan Sasmal, Sarit S. Agasti, Deepak Nair, and Kobi Rosenblum. "Measuring mRNA translation in neuronal processes and somata by tRNA-FRET." Nucleic Acids Research 48, no. 6 (January 24, 2020): e32-e32. http://dx.doi.org/10.1093/nar/gkaa042.

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Abstract In neurons, the specific spatial and temporal localization of protein synthesis is of great importance for function and survival. Here, we visualized tRNA and protein synthesis events in fixed and live mouse primary cortical culture using fluorescently-labeled tRNAs. We were able to characterize the distribution and transport of tRNAs in different neuronal sub-compartments and to study their association with the ribosome. We found that tRNA mobility in neural processes is lower than in somata and corresponds to patterns of slow transport mechanisms, and that larger tRNA puncta co-localize with translational machinery components and are likely the functional fraction. Furthermore, chemical induction of long-term potentiation (LTP) in culture revealed up-regulation of mRNA translation with a similar effect in dendrites and somata, which appeared to be GluR-dependent 6 h post-activation. Importantly, measurement of protein synthesis in neurons with high resolutions offers new insights into neuronal function in health and disease states.

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Antonny, Bruno, Joëlle Bigay, and Bruno Mesmin. "The Oxysterol-Binding Protein Cycle: Burning Off PI(4)P to Transport Cholesterol." Annual Review of Biochemistry 87, no. 1 (June 20, 2018): 809–37. http://dx.doi.org/10.1146/annurev-biochem-061516-044924.

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To maintain an asymmetric distribution of ions across membranes, protein pumps displace ions against their concentration gradient by using chemical energy. Here, we describe a functionally analogous but topologically opposite process that applies to the lipid transfer protein (LTP) oxysterol-binding protein (OSBP). This multidomain protein exchanges cholesterol for the phosphoinositide phosphatidylinositol 4-phosphate [PI(4)P] between two apposed membranes. Because of the subsequent hydrolysis of PI(4)P, this counterexchange is irreversible and contributes to the establishment of a cholesterol gradient along organelles of the secretory pathway. The facts that some natural anti-cancer molecules block OSBP and that many viruses hijack the OSBP cycle for the formation of intracellular replication organelles highlight the importance and potency of OSBP-mediated lipid exchange. The architecture of some LTPs is similar to that of OSBP, suggesting that the principles of the OSBP cycle—burning PI(4)P for the vectorial transfer of another lipid—might be general.

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Paradhipta, Dimas Hand Vidya, Seong Shin Lee, Hyuk jun lee, Young Ho Joo, In-Hag Choi, and Sam Churl Kim. "PSXI-36 Effects of antifungal and fibrinolytic inoculants on fermentation quality, rumen digestibility, and aerobic stability of rye silage harvested at early dough stage." Journal of Animal Science 97, Supplement_3 (December 2019): 403–4. http://dx.doi.org/10.1093/jas/skz258.801.

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Abstract This study estimated the effects of new inoculants on fermentation quality and rumen digestibility of rye silage with different moisture contents. New inoculants were isolated for producing antifungal substances (Lactobacillus brevis 100D8) and fibrinolytic enzymes (Leuconostoc holzapfelii 5H4), and mixed at 1:1 ratio. Rye forage was harvested at 20 days after heading stage, and chopped into 3–5 cm length. The chopped forage ensiled immediately (high moisture, High) or after 8 h wilting (low moisture, Low) into 10-L mini silo (8kg) with new inoculants at 7.5 × 105 cfu/g (MIX) or commercial inoculant (L. plantarum CMbio) at 8.0 × 105 cfu/g (LPT) for 100 days in quadruplicate. Wilting process did not affect chemical compositions of rye forages, except dry matter (DM) content (P < 0.001; 42.8 vs. 34.7%) was higher in High than in Low. Rye silage in High had lower (P < 0.001) DM with higher (P < 0.05) neutral detergent fiber (NDF), and in vitro digestibilities of DM (IVDMD) and NDF (IVNDFD) than in Low. Additionally, NDF (P < 0.01), hemicellulose (P = 0.005), IVDMD (P = 0.005), and IVNDFD (P = 0.045) of rye silages were higher in MIX than those in LPT. Rye silage had lower (P < 0.05) pH by High or MIX application. Acetate concentration of rye silage was higher (P < 0.01) in MIX than in LPT, but lower (P < 0.001) lactate to acetate ratio. Yeast was lower (P = 0.006) in MIX than in LTP. There were the interaction effects (P < 0.05) between moisture and inoculant on ammonia-N, lactate, propionate, lactic acid bacteria, and aerobic stability of rye silage. Therefore, this study could conclude that new inoculant improved the fermentation quality of rye silage harvested at early dough stage, which showed the beneficial effects on rumen digestibility with high moisture rye forage and on aerobic stability with low moisture.

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Zhang, Bin, Wen Lu, Weiqing Fang, Wu Ma, and Fusheng Xue. "Differential roles of GluN2B in two types of chemical‐induced LTP‐mediated phosphorylation regulation of GluA1 at serine 845 in hippocampal slices." FASEB Journal 34, S1 (April 2020): 1. http://dx.doi.org/10.1096/fasebj.2020.34.s1.00228.

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KAMPUNZU, A. B., P. AKANYANG, R. B. M. MAPEO, B. N. MODIE, and M. WENDORFF. "Geochemistry and tectonic significance of the Mesoproterozoic Kgwebe metavolcanic rocks in northwest Botswana: implications for the evolution of the Kibaran Namaqua-Natal Belt." Geological Magazine 135, no. 5 (September 1998): 669–83. http://dx.doi.org/10.1017/s001675689800123x.

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The c. 1.1 Ga Kgwebe metavolcanic rocks exposed in the northwest of Botswana are late Kibaran rocks. They represent a bimodal suite of Within-Plate low titanium-phosphorus (LTP) continental tholeiites and post-orogenic Within-Plate high-K rhyolites. The chemical compositions of the Kgwebe mafic rocks are characterized by low values of Ce/Pb (<10) and high La/Nb ratios (average c. 2, maximum 4). Mid-ocean ridge basalts (MORB)-normalized spidergrams show marked enrichment in mobile elements (Sr, K, Rb, Ba) and negative anomalies in Nb. These features suggest they may have originated in a mantle, enriched during a previous subduction event. The Kgwebe metarhyolites are marked by Y>60 ppm, Sr/Y<1, Rb/Th>20 and high K-contents. They cannot therefore be the product of melting of sediments or a subducting slab. It is inferred that they represent felsic magmas resulting from melting of Mesoproterozoic (Kibaran) calcalkaline rocks underplated in the middle and/or lower crust. The Kgwebe bimodal metavolcanic rocks pre-date the Neoproterozoic Ghanzi Group rocks which are correlated with the lower part of the Damara sequence. The chemical composition and field relations suggest that these metavolcanic rocks were emplaced during a late orogenic collision-associated extensional collapse. This collapse affected a crust thickened during the Kibaran orogeny in the Namaqua-Natal Belt of southwest Africa.

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Gabriel, Jonathan, Alice Warley, Frances Edwards, Philip Beesley, and Katalin Torok. "Spatial Distribution Patterns of Alpha-CaMKII in Hippocampal Tissue Suggest Role for Transient Not Persistent Translocation in Chemical LTP and Persistent Clustering in Ischemia." Biophysical Journal 104, no. 2 (January 2013): 615a. http://dx.doi.org/10.1016/j.bpj.2012.11.3406.

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Martínez-Jarquín, Sandra, Abigail Moreno-Pedraza, Daniel Cázarez-García, and Robert Winkler. "Automated chemical fingerprinting of Mexican spirits derived from Agave (tequila and mezcal) using direct-injection electrospray ionisation (DIESI) and low-temperature plasma (LTP) mass spectrometry." Analytical Methods 9, no. 34 (2017): 5023–28. http://dx.doi.org/10.1039/c7ay00793k.

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Lim, Dmitry, Lisa Mapelli, Pier Luigi Canonico, Francesco Moccia, and Armando A. Genazzani. "Neuronal Activity-Dependent Activation of Astroglial Calcineurin in Mouse Primary Hippocampal Cultures." International Journal of Molecular Sciences 19, no. 10 (September 30, 2018): 2997. http://dx.doi.org/10.3390/ijms19102997.

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Astrocytes respond to neuronal activity by generating calcium signals which are implicated in the regulation of astroglial housekeeping functions and/or in modulation of synaptic transmission. We hypothesized that activity-induced calcium signals in astrocytes may activate calcineurin (CaN), a calcium/calmodulin-regulated protein phosphatase, implicated in neuropathology, but whose role in astroglial physiology remains unclear. We used a lentiviral vector expressing NFAT-EYFP (NY) fluorescent calcineurin sensor and a chemical protocol of LTP induction (cLTP) to show that, in mixed neuron-astrocytic hippocampal cultures, cLTP induced robust NY translocation into astrocyte nuclei and, hence, CaN activation. NY translocation was abolished by the CaN inhibitor FK506, and was not observed in pure astroglial cultures. Using Fura-2 single cell calcium imaging, we found sustained Ca2+ elevations in juxtaneuronal, but not distal, astrocytes. Pharmacological analysis revealed that both the Ca2+ signals and the nuclear NY translocation in astrocytes required NMDA and mGluR5 receptors and depended on extracellular Ca2+ entry via a store-operated mechanism. Our results provide a proof of principle that calcineurin in astrocytes may be activated in response to neuronal activity, thereby delineating a framework for investigating the role of astroglial CaN in the physiology of central nervous system.

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Shen, Zongjie, Chun Zhao, Yanfei Qi, Wangying Xu, Yina Liu, Ivona Z. Mitrovic, Li Yang, and Cezhou Zhao. "Advances of RRAM Devices: Resistive Switching Mechanisms, Materials and Bionic Synaptic Application." Nanomaterials 10, no. 8 (July 23, 2020): 1437. http://dx.doi.org/10.3390/nano10081437.

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Resistive random access memory (RRAM) devices are receiving increasing extensive attention due to their enhanced properties such as fast operation speed, simple device structure, low power consumption, good scalability potential and so on, and are currently considered to be one of the next-generation alternatives to traditional memory. In this review, an overview of RRAM devices is demonstrated in terms of thin film materials investigation on electrode and function layer, switching mechanisms and artificial intelligence applications. Compared with the well-developed application of inorganic thin film materials (oxides, solid electrolyte and two-dimensional (2D) materials) in RRAM devices, organic thin film materials (biological and polymer materials) application is considered to be the candidate with significant potential. The performance of RRAM devices is closely related to the investigation of switching mechanisms in this review, including thermal-chemical mechanism (TCM), valance change mechanism (VCM) and electrochemical metallization (ECM). Finally, the bionic synaptic application of RRAM devices is under intensive consideration, its main characteristics such as potentiation/depression response, short-/long-term plasticity (STP/LTP), transition from short-term memory to long-term memory (STM to LTM) and spike-time-dependent plasticity (STDP) reveal the great potential of RRAM devices in the field of neuromorphic application.

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Akhiyarova, Guzel R., Ruslan S. Ivanov, Igor I. Ivanov, Ekaterina I. Finkina, Daria N. Melnikova, Ivan V. Bogdanov, Tatyana Nuzhnaya, Tatiana V. Ovchinnikova, Dmitriy S. Veselov, and Guzel R. Kudoyarova. "Effects of Salinity and Abscisic Acid on Lipid Transfer Protein Accumulation, Suberin Deposition and Hydraulic Conductance in Pea Roots." Membranes 11, no. 10 (October 1, 2021): 762. http://dx.doi.org/10.3390/membranes11100762.

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Lipid transfer proteins (LTPs) participate in many important physiological processes in plants, including adaptation to stressors, e.g., salinity. Here we address the mechanism of this protective action of LTPs by studying the interaction between LTPs and abscisic acid (ABA, a “stress” hormone) and their mutual participation in suberin deposition in root endodermis of salt-stressed pea plants. Using immunohistochemistry we show for the first time NaCl induced accumulation of LTPs and ABA in the cell walls of phloem paralleled by suberin deposition in the endoderm region of pea roots. Unlike LTPs which were found localized around phloem cells, ABA was also present within phloem cells. In addition, ABA treatment resulted in both LTP and ABA accumulation in phloem cells and promoted root suberization. These results suggested the importance of NaCl-induced accumulation of ABA in increasing the abundance of LTPs and of suberin. Using molecular modeling and fluorescence spectroscopy we confirmed the ability of different plant LTPs, including pea Ps-LTP1, to bind ABA. We therefore hypothesize an involvement of plant LTPs in ABA transport (unloading from phloem) as part of the salinity adaptation mechanism.

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Mamonov, V. I. "Analysis of plasma effect on ultrahigh-molecular weight polyethylene fibers’ surface energy on strength of fibers and fiber reinforced composites." Perspektivnye Materialy 3 (2021): 42–54. http://dx.doi.org/10.30791/1028-978x-2021-3-42-54.

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Completely saturated chemical bonds in ultrahigh-molecular-weight polyethylene (UHMWPE) fibers — are a reason for their low surface energy (FSE), i.e. inert properties. Elongated crystal structure of UHMWPE molecules ensures high anisotropic tensile strength of the fibers. An inertness is a problem for utilization these fibers in high-strength composites production. Surface energy (SE) difference of the fibers and a binder in fiber/matrix system hinders chemical interaction at interphase boundary and worsens fiber wettability. Increase in their FSE is a topical task for this problem decision. Necessary condition of FSE increase is the integrity of molecule structure, lying under modified surface. Low temperature, nonequilibrium plasma (LTP) treatment in a medium of argon and argon/propane mixture, used in this work for plasma activation of fibers’ surface, permits to abide by this condition. However, plasma ion bombardment during a process of activation can modify interior crystal structure and, as a result, decrease their strength. The rovings SK75 (Holland) and D800 (China) were used for study of the properties of UHMWPE fibers after plasma treatment. Activation effect on FSE, strength, and fibers’ wetting by water and epoxy binder before and after ageing was studied. Capillary wetting of the fibers by distilled water used for FSE evaluation. The data of filaments surface structure and their diameter change at maximal load, obtained by optical microscope study, were used for the analysis of FSE and epoxy matrix effect on the strength of fiber/matrix systems. Essential distinction of SK75 and D800 fibers properties is ascertained. Negative effect of fibers’ and matrix’s stiffness, as well as increased FSE of stiff fibers on the strength of fiber/matrix system is revealed.

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Song, Chenchen, Shuang Wang, Weimin Wang, Chuting Xu, Guobi Chai, Lingbo Ji, Jianxun Zhang, Weiping Yang, and Wuduo Zhao. "Non-contact light-radiation thermal desorption-assisted LTP ionization miniature ion trap mass spectrometry for rapid analysis of the flavouring substances in pipe tobacco." Analytical Methods 11, no. 10 (2019): 1410–15. http://dx.doi.org/10.1039/c8ay02784f.

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Journal articles on the topic 'Chemical LTP'

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