12,818 research outputs found
Kinematic properties of the dual AGN system J0038+4128 based on long-slit spectroscopy
The study of kiloparsec-scale dual active galactic nuclei (AGN) will provide
important clues to understand the co-evolution between the host galaxies and
their central supermassive black holes undergoing a merging process. We present
long-slit spectroscopy of the J00384128, a kiloparsec-scale dual AGN
candidate discovered by Huang et al. recently, using the Yunnan Faint Object
Spectrograph and Camera (YFOSC) mounted on Li-Jiang 2.4-m telescope at Yunnan
observatories. From the long-slit spectra, we find that the average relative
line-of-sight (LOS) velocity between the two nuclei (J00384128N and
J00384128S) is about 150 km s. The LOS velocities of the emission
lines from the gas ionized by the nuclei activities and of the absorption lines
from stars governed by the host galaxies for different regions of the
J00384128 exhibit the same trend. The same velocities trend indicates that
the gaseous disks are co-rotating with the stellar disks in this ongoing merge
system. We also find several knots/giant HII regions scattered around the two
nuclei with strong star formation revealed by the observed line ratios from the
spectra. Those regions are also detected clearly in HST -band and HST
-band images.Comment: 12 pages, 5 figures, 3 tables, Research in Astronomy and Astrophysics
accepte
Entanglement concentration for unknown atomic entangled states via entanglement swapping
An entanglement concentration scheme for unknown atomic entanglement states
is proposed via entanglement swapping in cavity QED. Because the interaction
used here is a large-detuned one between two driven atoms and a quantized
cavity mode, the effects of the cavity decay and thermal field have been
eliminated. These advantages can warrant the experimental feasibility of the
current scheme.Comment: 4 page
Tetramethylpyrazine protects Schwann cells from ischemia-like injury and increases cell survival in cold ischemic rat nerves
Tetrametilpirazina (TMP), o principal componente do extrato de Ligusticum wallichi Franchat (erva chinesa), apresenta propriedades neuroprotetoras na isquemia. Nesse estudo, avaliamos seus efeitos protetores nas células de Schwann (SC), cultivando-as na presença de condições de depleção de oxigênio da glicose (OGD) e medindo a sobrevivência dos nervos de ratos isquêmicos pelo resfriamento. No modelo de lesão isquêmica em SC induzida por OGD, demonstramos que o tratamento com TMP não somente reduziu as perdas de viabilidade celular induzida por OGD, a morte celular, a apoptose de SC dose-dependente e inibiu a liberação de LDH, mas, também, suprimiu a infra-regulação do Vcl-2 e a supra-regulação de Bax e caspase-3, e inibiu a consequente ativação da caspase-3. No modelo de nervo isquêmico por resfriamento, observamos que a exposição prolongada ao resfriamento por quatro semanas estava, marcadamente, associada com a ausência de SC, com o decréscimo da viabilidade celular e a apoptose em segmentos de nervo incubados na solução da Universidade de Wisconsin apenas. Entretanto, a TMP atenuou o dano no segmento do nervo preservando SC e antagonizando a diminuição da viabilidade da fibra nervosa e o aumento das células TUNEL-positiva de modo dose-dependente. De forma conjunta, nossos resultados indicam que o TMP não só fornece efeitos protetores em um modelo de dano semelhante à isquemia de SC de ratos cultivados pela regulação de BCl-2, Bax e caspase 3, mas, também, aumenta a sobrevivência celular e suprime a apoptose no modelo de isquemia por resfriamento por exposição prolongada por quatro semanas. Então, TMP pode ser uma estratégia terapêutica eficaz para prevenir doenças isquêmicas do sistema nervoso periférico e melhora a armazenagem do nervo periférico.Tetramethylpyrazine (TMP), a major active ingredient of Ligusticum wallichi Franchat extract (a Chinese herb), exhibits neuroprotective properties in ischemia. In this study, we assessed its protective effects on Schwann cells (SCs) by culturing them in the presence of oxygen glucose deprivation (OGD) conditions and measuring cell survival in cold ischemic rat nerves. In the OGD-induced ischemic injury model of SCs, we demonstrated that TMP treatment not only reduced OGD-induced cell viability losses, cell death, and apoptosis of SCs in a dose-dependent manner, and inhibited LDH release, but also suppressed OGD-induced downregulation of Bcl-2 and upregulation of Bax and caspase-3, as well as inhibited the consequent activation of caspase-3. In the cold ischemic nerve model, we found that prolonged cold ischemic exposure for four weeks was markedly associated with the absence of SCs, a decrease in cell viability, and apoptosis in preserved nerve segments incubated in University of Wisconsin solution (UWS) alone. However, TMP attenuated nerve segment damage by preserving SCs and antagonizing the decrease in nerve fiber viability and increase in TUNEL-positive cells in a dose-dependent manner. Collectively, our results indicate that TMP not only provides protective effects in an ischemia-like injury model of cultured rat SCs by regulating Bcl-2, Bax, and caspase-3, but also increases cell survival and suppresses apoptosis in the cold ischemic nerve model after prolonged ischemic exposure for four weeks. Therefore, TMP may be a novel and effective therapeutic strategy for preventing peripheral nervous system ischemic diseases and improving peripheral nerve storage
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