13,344 research outputs found
Early-stage star forming cloud cores in GLIMPSE Extended Green Objects (EGOs) as traced by organic species
In order to investigate the physical and chemical properties of massive star
forming cores in early stages, we analyse the excitation and abundance of four
organic species, CH3OH, CH3OCH3, HCOOCH3 and CH3CH2CN, toward 29 Extended Green
Object (EGO) cloud cores that were observed by our previous single dish
spectral line survey. The EGO cloud cores are found to have similar methanol
J_3-J_2 rotation temperatures of ~44 K, a typical linear size of ~0.036 pc, and
a typical beam averaged methanol abundance of several 10^(-9) (the beam
corrected value could reach several 10^(-7)). The abundances of the latter
three species, normalized by that of methanol, are found to be correlated also
across a large variety of clouds such as EGO cloud cores, hot corinos, massive
hot cores and Galactic Center clouds. The chemical properties of the EGO cloud
cores lie between that of hot cores and hot corinos. However, the abundances
and abundance ratios of the four species can not be satisfactorily explained by
recent chemical models either among the EGO cloud cores or among the various
types of cloud cores from literature
Induction of CCL8/MCP-2 by mycobacteria through the activation of TLR2/PI3K/Akt signaling pathway.
Pleural tuberculosis (TB), together with lymphatic TB, constitutes more than half of all extrapulmonary cases. Pleural effusions (PEs) in TB are representative of lymphocytic PEs which are dominated by T cells. However, the mechanism underlying T lymphocytes homing and accumulation in PEs is still incompletely understood. Here we performed a comparative analysis of cytokine abundance in PEs from TB patients and non-TB patients by protein array analysis and observed that MCP-2/CCL8 is highly expressed in the TB-PEs as compared to peripheral blood. Meanwhile, we observed that CCR5, the primary receptor used by MCP-2/CCL8, is mostly expressed on pleural CD4(+) T lymphocytes. Furthermore, we found that infection with either Mycobacterium bovis Bacillus Calmette-Guérin (BCG) or Mycobacterium tuberculosis H37Rv induced production of MCP-2/CCL8 at both transcriptional and protein level in Raw264.7 and THP-1 macrophage cells, mouse peritoneal macrophages as well as human PBMC monocyte-derived macrophages (MDMs). The induction of MCP-2/CCL8 by mycobacteria is dependent on the activation of TLR2/PI3K/Akt and p38 signaling pathway. We conclude that accumulation of MCP-2/CCL8 in TB-PEs may function as a biomarker for TB diagnosis
Montmorillonite as a multifunctional adsorbent can simultaneously remove crystal violet, cetyltrimethylammonium, and 2-naphthol from water
Giant photoinduced lattice distortion in oxygen-vacancy ordered SrCoO2.5 thin films
Despite of the tremendous efforts spent on the oxygen vacancy migration in
determining the property optimization of oxygen-vacancy enrichment transition
metal oxides, few has focused on their dynamic behaviors non-equilibrium
states. In this work, we performed multi-timescale ultrafast X-ray diffraction
measurements by using picosecond synchrotron X-ray pulses and femtosecond
table-top X-ray pulses to monitor the structural dynamics in the oxygen-vacancy
ordered SrCoO2.5 thin films. A giant photoinduced strain ({\Delta}c/c > 1%) was
observed, whose distinct correlation with the pump photon energy indicates a
non-thermal origin of the photoinduced strain. The sub-picosecond resolution
X-ray diffraction reveals the formation and propagation of the coherent
acoustic phonons inside the film. We also simulate the effect of photoexcited
electron-hole pairs and the resulting lattice changes using the Density
Function Theory method to obtain further insight on the microscopic mechanism
of the measured photostriction effect. Comparable photostrictive responses and
the strong dependence on excitation wavelength are predicted, revealing a
bonding to anti-bonding charge transfer or high spin to intermediate spin
crossover induced lattice expansion in the oxygen-vacancy films.Comment: 12 pages, 4 figures, support materia
- …
