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991.
Sergei Ovchinnikov 《国际智能系统杂志》1999,14(4):413-418
We establish a complete characterization of the class of ordinal OWA operators in terms of their invariance properties ©1999 John Wiley & Sons, Inc. 相似文献
992.
Eyal Bressler Sergei Braun 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2000,75(1):66-72
A novel liquid membrane reactor was designed to carry out the conversion of citric acid to itaconic (methylene succinic) acid by the fungus Aspergillus terreus. This bioreactor contained two supported liquid membranes (SLMs) that divided it into three compartments: (1) the feed chamber containing citric acid; (2) the reaction chamber containing the enzyme A terreus cells; and (3) the product collection chamber containing the counter‐ion. The specificity of SLMs allows the unidirectional flow, of the substrate from the feed to the reaction chamber, and of the product from the reaction to the product chamber in exchange for a counter‐ion, thus maintaining low concentrations of both the product and the substrate, and limiting their inhibitory effects on the conversion process. The yield of itaconic acid in the membrane bioreactor was about two orders of magnitude higher than in the batch process. © 2000 Society of Chemical Industry 相似文献
993.
The rupture of a liquid film driven by friction with a gas flow in a horizontal minichannel and the heat-exchange crisis in
this film locally heated by a 1 × 1 cm source in the channel wall has been experimentally studied. A heat flux of 250 W/cm2 is achieved, which is greater by an order of magnitude than the limiting heat flux for a vertically falling liquid film with
the same Reynolds number (Re
l
= 21). These experiments confirmed good prospects for using gas-flow-driven liquid films in cooling systems of devices with
intense local heat evolution. 相似文献
994.
Sergei Y. Grishin Pavel A. Domnin Sergey V. Kravchenko Viacheslav N. Azev Leila G. Mustaeva Elena Y. Gorbunova Margarita I. Kobyakova Alexey K. Surin Maria A. Makarova Stanislav R. Kurpe Roman S. Fadeev Alexey S. Vasilchenko Victoria V. Firstova Svetlana A. Ermolaeva Oxana V. Galzitskaya 《International journal of molecular sciences》2021,22(18)
The development and testing of new antimicrobial peptides (AMPs) represent an important milestone toward the development of new antimicrobial drugs that can inhibit the growth of pathogens and multidrug-resistant microorganisms such as Pseudomonas aeruginosa, Gram-negative bacteria. Most AMPs achieve these goals through mechanisms that disrupt the normal permeability of the cell membrane, which ultimately leads to the death of the pathogenic cell. Here, we developed a unique combination of a membrane penetrating peptide and peptides prone to amyloidogenesis to create hybrid peptide: “cell penetrating peptide + linker + amyloidogenic peptide”. We evaluated the antimicrobial effects of two peptides that were developed from sequences with different propensities for amyloid formation. Among the two hybrid peptides, one was found with antibacterial activity comparable to antibiotic gentamicin sulfate. Our peptides showed no toxicity to eukaryotic cells. In addition, we evaluated the effect on the antimicrobial properties of amino acid substitutions in the non-amyloidogenic region of peptides. We compared the results with data on the predicted secondary structure, hydrophobicity, and antimicrobial properties of the original and modified peptides. In conclusion, our study demonstrates the promise of hybrid peptides based on amyloidogenic regions of the ribosomal S1 protein for the development of new antimicrobial drugs against P. aeruginosa. 相似文献
995.
É. D. Zamyshevskii Yu. N. Shebeko A. V. Trunev V. Yu. Navtsenya A. A. Zaitsev 《Combustion, Explosion, and Shock Waves》1998,34(2):117-122
Extinction conditions for diffusion flames of gases and vapors in various media were studied experimentally. The limiting
blowout velocities of a diffusion jet when heated H2−N2 and H2−H2O mixtures flow out into air were found. The minimum fire-extinguishing concentrations upon diffusion combustion of gases
(CH4 and C3H8) and liquids (A-76 gasoline) were measured.
Translated fromFizika Goreniya i Vzryva, Vol. 34, No. 2, pp. 3–8, March–April, 1998. 相似文献
996.
Liudmila Spirina Alexandra Avgustinovich Sergei Afanasev Maxim Volkov Alexey Dobrodeev Olga Cheremisina Dmitry Kostromitsky 《International journal of molecular sciences》2021,22(20)
Introduction: The programmed death receptor ligand 1 (PD-L1) immunohistochemistry (IHC) assay is a widely used selection method for pembrolizumab treatment in gastric cancer (GC) patients. PD-L1 is the main regulator of immunity in oncogenesis. Material and methods: The study included 38 patients with GC. The combined treatment consisted of neoadjuvant FOLFOX6, or FLOT, chemotherapy and surgery. PD-L1 + tumor status was recorded in 12 patients (CPS > 5), with a negative status recorded in 26 patients. RT-PCR determined the expression of molecular markers. The level of LC3B protein was detected by Western Blotting analysis. Results: An overexpression of PD-1, PD-L2 in the tumor is associated with AKT/mTOR mRNA profile change and autophagy initiation in IHC PD-L1 positive GCs. NACT influences these biological features, modifying the expression of AKT/mTOR components and autophagic flux. In PD-L1 positive cancers, the effect of NACT and molecular markers rearrangements are essential compared to the PD-L1 negative cancers. Conclusion: The IHC PD-L1 status in gastric cancers is the significant marker of cancer progression, recovering the multiple inner mechanisms of cancer spreading and leading to ineffective therapy. Autophagy induction and angiogenesis are found in PD-L1 positive gastric cancers. 相似文献
997.
Vladimir B. Tsvetkov Irina V. Varizhuk Nikolay N. Kurochkin Sergei A. Surzhikov Igor P. Smirnov Andrey A. Stomakhin Natalia A. Kolganova Edward N. Timofeev 《International journal of molecular sciences》2022,23(7)
Oligonucleotide–peptide conjugates (OPCs) are a promising class of biologically active compounds with proven potential for improving nucleic acid therapeutics. OPCs are commonly recognized as an efficient instrument to enhance the cellular delivery of therapeutic nucleic acids. In addition to this application field, OPCs have an as yet unexplored potential for the post-SELEX optimization of DNA aptamers. In this paper, we report the preparation of designer thrombin aptamer OPCs with peptide side chains anchored to a particular thymidine residue of the aptamer. The current conjugation strategy utilizes unmodified short peptides and support-bound protected oligonucleotides with activated carboxyl functionality at the T3 thymine nucleobase. The respective modification of the oligonucleotide strand was implemented using N3-derivatized thymidine phosphoramidite. Aptamer OPCs retained the G-quadruplex architecture of the parent DNA structure and showed minor to moderate stabilization. In a series of five OPCs, conjugates bearing T3–Ser–Phe–Asn (SFN) or T3–Tyr–Trp–Asn (YWN) side chains exhibited considerably improved anticoagulant characteristics. Molecular dynamics studies of the aptamer OPC complexes with thrombin revealed the roles of the amino acid nature and sequence in the peptide subunit in modulating the anticoagulant activity. 相似文献
998.
Aleksandra Kvetkina Evgeny Pislyagin Ekaterina Menchinskaya Ekaterina Yurchenko Rimma Kalina Sergei Kozlovskiy Leonid Kaluzhskiy Alexander Menshov Natalia Kim Steve Peigneur Jan Tytgat Alexis Ivanov Naira Ayvazyan Elena Leychenko Dmitry Aminin 《International journal of molecular sciences》2022,23(9)
Parkinson’s disease (PD) is a socially significant disease, during the development of which oxidative stress and inflammation play a significant role. Here, we studied the neuroprotective effects of four Kunitz-type peptides from Heteractis crispa and Heteractis magnifica sea anemones against PD inductors. The peptide HCIQ1c9, which was obtained for the first time, inhibited trypsin less than other peptides due to unfavorable interactions of Arg17 with Lys43 in the enzyme. Its activity was reduced by up to 70% over the temperature range of 60–100 °C, while HCIQ2c1, HCIQ4c7, and HMIQ3c1 retained their conformation and stayed active up to 90–100 °C. All studied peptides inhibited paraquat- and rotenone-induced intracellular ROS formation, in particular NO, and scavenged free radicals outside the cells. The peptides did not modulate the TRPV1 channels but they affected the P2X7R, both of which are considered therapeutic targets in Parkinson’s disease. HMIQ3c1 and HCIQ4c7 almost completely inhibited the ATP-induced uptake of YO-PRO-1 dye in Neuro-2a cells through P2X7 ion channels and significantly reduced the stable calcium response in these cells. The complex formation of the peptides with the P2X7R extracellular domain was determined via SPR analysis. Thus, these peptides may be considered promising compounds to protect neuronal cells against PD inductors, which act as ROS production inhibitors and partially act as ATP-induced P2X7R activation inhibitors. 相似文献
999.
Jiying Li Erik T. Brown Sean A. Crowe Sergei Katsev 《Journal of Great Lakes research》2018,44(6):1221-1234
The biogeochemical functioning of large tropical lakes differs substantially from temperate lakes, yet remains poorly understood. We characterized the carbon, nitrogen, and phosphorus cycling in the water column and sediments of a deep meromictic tropical Lake Malawi (East Africa) by measuring geochemical distributions and compiling whole-lake geochemical budgets. Four locations (100 to 650 m water depth) were characterized. The results reveal that sediments contribute significantly to lake-wide biogeochemical budgets. Sedimentation rates have significantly increased in recent decades. While the export efficiency of organic matter from photic zone to deep sediments is low (14%), organic carbon is buried in the anoxic sediments with high efficiency (27–46%). Area-specific rates of carbon mineralization (4.1 mmol m? 2 d? 1) are similar to those in temperate well-oxygenated large lakes and marine sediments in similar water depths. Ammonium effluxes from sediments (0.44 mmol m? 2 d? 1) contribute 29% to the total nitrogen inputs into the water column, while sediment denitrification (0.035 mmol m? 2 d? 1) and burial of organic nitrogen (0.27 mmol m? 2 d? 1) remove 28% of total inputs in the lake. The recycling efficiency of phosphorus in anoxic sediments is high (73%). P effluxes average 0.037 mmol m? 2 d? 1, suggesting a large and previously unquantified contribution (42%) to water column P inputs. The results underscore the importance of sediments in the geochemical budgets of even large lakes and suggest trends in lacustrine carbon cycling that hold across a wide range of environments. 相似文献
1000.
Shamil Akhmedov Sergey Afanasyev Natalia Beshchasna Marina Trusova Ivan Stepanov Mariya Rebenkova Ekaterina Poletykina Yuri Vecherskiy Sergei Tverdokhlebov Evgeny Bolbasov Sascha Balakin Joerg Opitz Anatoly Yermakov Boris Kozlov 《International journal of molecular sciences》2022,23(15)
The high mortality rate caused by atherosclerosis makes it necessary to constantly search for new and better treatments. In previous reports, chemically modified carbon-coated iron nanoparticles (Fe@C NPs) have been demonstrated a high biocompatibility and promising anti-plaque properties. To further investigate these effects, the interaction of these nanoparticles with the adipose tissue of Wistar rats (in vivo) and human atherosclerotic plaques (ex vivo) was studied. For the in vivo study, cobalt–chromium (CoCr) alloy tubes, which are used for coronary stent manufacturing, were prepared with a coating of polylactic acid (PLA) which contained either modified or non-modified Fe@C NPs in a 5% by weight concentration. The tubes were implanted into an area of subcutaneous fat in Wistar rats, where changes in the histological structure and functional properties of the surrounding tissue were observed in the case of coatings modified with Fe@C NPs. For the ex vivo study, freshly explanted human atherosclerotic plaques were treated in the physiological solution with doses of modified Fe@C NPs, with mass equal to 5% or 25% relative to the plaques. This treatment resulted in the release of cholesterol-like compounds from the surface of the plaques into the solution, thus proving a pronounced destructive effect on the plaque structure. Chemically modified Fe@C NPs, when used as an anti-atherosclerosis agent, were able to activate the activity of macrophages, which could lead to the destruction of atherosclerotic plaques structures. These findings could prove the fabrication of next-generation vascular stents with built-in anti-atherosclerotic agents. 相似文献