126 research outputs found

    Импортозамещение межсекционных уплотнений на примере многоступенчатого насоса "Grundfos"

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    Bronchoconstriction is a characteristic symptom of various chronic obstructive respiratory diseases such as chronic obstructive pulmonary disease (COPD) and asthma. Precision-cut lung slices (PCLS) are a suitable ex vivo model to study physiological mechanisms of bronchoconstriction in different species. In the present study, we established an ex vivo model of bronchoconstriction in non-human primates (NHPs). PCLS prepared from common marmosets, cynomolgus macaques, rhesus macaques, and anubis baboons were stimulated with increasing concentrations of representative bronchoconstrictors: methacholine, histamine, serotonin, leukotriene D4 (LTD4), U46619, and endothelin-1. Alterations in the airway caliber were measured and compared to previously published data from rodents, guinea pigs, and humans. Methacholine induced maximal airway constriction, varying between 74 and 88% in all NHP species, whereas serotonin was ineffective. Histamine induced maximal bronchoconstriction of 77 to 90% in rhesus macaques, cynomolgus macaques, and baboons, and a lesser constriction of 53% in marmosets. LTD4 was ineffective in marmosets and rhesus macaques, but induced a maximum constriction of 44 to 49% in cynomolgus macaques and baboons. U46619 and endothelin-1 caused airway constriction in all NHP species, with maximum constrictions of 65 to 91%, and 70 to 81%, respectively. In conclusion, PCLS from NHPs represent a valuable ex vivo model for studying bronchoconstriction. All NHPs respond to mediators relevant to human airway disorders such as methacholine, histamine, U46619, endothelin-1 and are insensitive to the rodent mast cell product serotonin. Only PCLS from cynomolgus macaques and baboons, however, responded also to leukotrienes, suggesting that among all compared species, these two NHPs resemble the human airway mechanisms bes

    Study of electron transport in hydrocarbon gases

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    The drift velocity and the effective ionization coefficient of electrons in the organic gases, C2H2, C2H4, C2H6, CH3OH, C2H5OH, C6H6, and C6H5CH3, have been measured over relatively wide ranges of density-reduced electric fields (E/N) at room temperature (around 300 K). The drift velocity was measured, based on the arrival-time spectra of electrons by using a double-shutter drift tube over the E/N range from 300 to 2800 Td, and the effective ionization coefficient (alpha - eta) was determined by the steady-state Townsend method from 150 to 3000 Td. Whenever possible, these parameters were compared with those available in the literature. It has been shown that the swarm parameters for these gases have specific tendencies, depending on their molecular configurations

    Untersuchungen �ber die Entwicklung des Kanaldurchschlags in Gasen

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    Elektronenlawinen in elektronegativen Gasen

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    Zur r�umlichen Ausbreitung einer Entladung beim Generationen- und beim Kanalaufbau

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