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15812. Nociceptive behavior induced by chemotherapeutic paclitaxel and beneficial role of antioxidative pathways

Creator:
Miao, Hua, Xu, Jinrong, Xu, Dongsheng, Ma, Xiaohui, Zhao, Xiaoming, and Liu, Li
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
paclitaxel, neuropathic pain, Nrf2-ARE, SOD, NOX, and pro-inflammation
Language:
English
Description:
Paclitaxel is used for the treatment of several types of cancers. However, one of the significant limiting complications of paclitaxel is painful peripheral neuropathy during its therapy. In this study we examined the engagement of antioxidative signal pathway of the dorsal root ganglion (DRG) in mechanical and thermal hypersensitivity evoked by paclitaxel. Behavioral test was performed to determine mechanical and thermal sensitivity in rats. Western blot analysis and ELISA were used to examine expression of Nrf2-antioxidant response element (ARE) and superoxide dismutases (SOD); and the levels of products of oxidative stress in the DRG. Our results show that paclitaxel increased mechanical and thermal sensitivity as compared with vehicle control animals. Paclitaxel also impaired Nrf2-ARE and SOD in the DRG and amplified products of oxidative stress, namely 8-isoprostaglandin F2α and 8-hydroxy-2’- deoxyguanosine. Systemic administration of SOD mimetic using tempol, antioxidant vitamin C or blocking oxidative pathway using NADPH oxidase inhibitor (GKT137831) attenuated mechanical and thermal hypersensitivity induced by paclitaxel. This inhibitory effect was accompanied with decreases of proinflammatory cytokines (PICs) such as IL-1β, IL-6 and TNF-α in the DRG. In conclusion, the data revealed impairment of Nrf2-ARE and heightened oxidative and PIC signals in the DRG of paclitaxel rats, leading to neuropathic pain. Balancing of reactive oxygen species by supplying antioxidants and/or inhibiting NADPH oxidase appears significant to yield beneficial effects in neuropathic pain conditions after chemotherapeutic paclitaxel.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

15814. Noční pohledy na Zemi přístrojem Day/Night Band družice Suomi-NPP

Creator:
Setvák, Martin
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fyzika, družice meteorologické, Země, physics, weather satellites, Earth, 6, and 53
Language:
Czech and English
Description:
Družice Suomi-NPP je prototypem nové generace meteorologických družic JPSS. Jejím hlavním přístrojem je VIIRS, navazující na radiometry AVHRR a MODIS družic NOAA/POES, resp. Terra/Aqua. Jeho zcela novou součástí je vysoce citlivý přístroj DNB (Day/Night Band) určený primárně pro noční snímání Země a její atmosféry. Příspěvek dokumentuje citlivost přístroje DNB na několika vybraných příkladech., The Suomi/NPP satellite is a prototype of a new generation of weather satellites, JPSS. Its main instrument is VIIRS, a follow-up instrument of the NOA/POES and Metop AVHRR radiometer, and of the Terra/Aqua MODIS instrument. One of its main advances is a brand new Day/Night Band (DNB), designed primarily for night-time imaging of the Earth and its atmosphere. This short article documents the ultimate DNB low-light sensitivity of several selected cases., Martin Setvák., and Obsahuje seznam literatury
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

15815. Nodal solutions for a second-order $m$-point boundary value problem

Creator:
Ma, Ruyun
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
multiplicity results, eigenvalues, bifurcation methods, nodal zeros, and multi-point boundary value problems
Language:
English
Description:
We study the existence of nodal solutions of the $m$-point boundary value problem \[ u^{\prime \prime }+ f(u)=0, \quad 0<t<1, u^{\prime }(0)=0, \quad u(1)=\sum ^{m-2}_{i=1} \alpha _i u(\eta _i) \] where $\eta _i\in \mathbb{Q}$ $(i=1, 2, \cdots , m-2)$ with $0<\eta _1<\eta _2<\cdots <\eta _{m-2}<1$, and $\alpha _i\in \mathbb{R}$ $(i=1, 2, \cdots , m-2)$ with $\alpha _i>0$ and $0<\sum \nolimits ^{m-2}_{i=1} \alpha _i < 1$. We give conditions on the ratio $f(s)/s$ at infinity and zero that guarantee the existence of nodal solutions. The proofs of the main results are based on bifurcation techniques.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

15816. Noise analysis and optimization of gearboxes

Creator:
Hajžman, Michal and Zeman, Vladimír
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
vibrations, noise, optimization, gearbox, and modal synthesis method
Language:
English
Description:
Gearboxes and similar machines containing rotating parts are complex systems with complicated structure and couplings. Generally they can be decomposed into more simple subsystems. These subsystems are usually rotating shafts with gears joined by gear couplings and housing coupled with rotating shafts by bearings. The paper is aimed at the mathematical modelling of gearboxes with spur helical gears considered including their interior rotating shaft system and housing. The used bearing model respects real number of rolling elements and roller contact forces acting between the journals and the outer housing. The model of a complete gearbox is created using the modal synthesis method. The kinematic transmission errors in gear couplings are viewed as sources of excitation. Vibration and noise analysis of the gearbox housing is performed by means of the created model. Four types of objective functions suitable for optimization from the radiated noise point of view are proposed. The presented methodology is applied to the simple test-gearbox. and Obsahuje seznam literatury
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

15817. Noise influence on time resolution of SiPM photodetectors

Creator:
Chytka, Ladislav, Komárek, Tomáš, Nožka, Libor, Sýkora, Tomáš, and Urbášek, Vladimír
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
SiPM, MPPC, Cherenkov radiation, time-of-flight, Čerenkovovo záření, and detektory času průletu
Language:
Czech
Description:
Silicon photomultiplier (SiPM) detectors, also called multipixel photon counters (MPPC), are introduced together with their main characteristics. The focus is given on the timing performance of SiPMs, which is important for the Cherenkov time-of-flight applications, where the SiPMs provide time resolution of the 10 ps order. The time performance is, naturally, influenced by the readout electronic noise. A method for the evaluation of the noise contribution using a Monte Carlo simulation combined with the laboratory measurements is presented and demonstrated on an example of STMicroelectronics NRD09_1 and FBK SiPM-NUV3S SiPMs. The noise contribution to the time resolution depends on the SiPM pulse amplitude A as 1/A. and Článek představuje SiPM detektory, též nazývané MPPC, a jejich základní charakteristiky. Důraz je kladen na využití při měření času, což je důležité např. pro čerenkovské detektory pro měření času průletu, které při využití SiPM dosahují časového rozlišení řádově 10 ps. Přesnost měření času je ovlivněna šumem produkovaným vyčítací elektronikou. Článek představuje metodu pro vyhodnocení vlivu šumu využívající Monte Carlo simulaci v kombinaci s daty naměřenými v laboratoři. Metoda je demonstrována na příkladu dvou SiPM: STMicroelectronics NRD09_1 a FBK SiPM-NUV3S. Obě SiPM vykazují závislost příspěvku šumu k časovému rozlišení na amplitudě SiPM pulzu A ve tvaru 1/A.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

15818. Noise reduction of the differential sleeve bearing

Creator:
Mazůrek, Ivan, Klapka, Milan, and Roupec, Jakub
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
rolling bearing, vibration, radial stiffness, and virtual model
Language:
English
Description:
This article describes a technique for noise reduction of the differential bearings. Noise is excited by the mechanical looseness of the system and by the vibrations of the engine. The mathematical model enables the optimization of the radial stiffness of the differential bearings. A test rig has been designed for the simulation of the phenomenon outside the vehicle. Analytical software has been created that is capable of classifying the types of noise from the measured data. The optimal solution is tested on the rig at the end, thus proving that the technique works. and Obsahuje seznam literatury
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

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