6 research outputs found
Hierarchical Assembly and Aggregation-Induced Enhanced Emission of a Pair of Isostructural Zn<sub>14</sub> Clusters
Information of solid-state and solution
structures is crucial in the characterization of molecular clusters
and in advancing the understanding of their diverse properties. [Et<sub>3</sub>NH]<sub>2</sub>[Zn<sub>14</sub>(hmq)<sub>8</sub>(OH)<sub>4</sub>X<sub>10</sub>] [X = Cl and Br; H<sub>2</sub>hmq = 2-(hydroxymethyl)Āquinolin-8-ol]
consist of a peanut-shaped Zn<sub>10</sub>O<sub>12</sub> core, in
which the Zn atoms occupy the faces and corners of an octahedron and
are protected by bonded halogen atoms and bulky organic ligands. Observation
of the [Zn<sub>14</sub>(hmq)<sub>8</sub>(OH)<sub>4</sub>X<sub>10</sub>]<sup>2ā</sup> fragment in electrospray ionization mass spectrometry
(ESI-MS) suggests that the cluster is stable in solution. ESI-MS analyses
from dissolved crystals and mother liquors reveal that ZnĀ(hmq) self-assembles
to Zn<sub>5</sub>(hmq)<sub>4</sub>Cl, then dimerizes through four
[OH]<sup>ā</sup> bridges to Zn<sub>10</sub>(hmq)<sub>8</sub>(OH)<sub>4</sub>Cl<sub>2</sub>, and progressively captures four ZnCl<sub>2</sub> one-by-one to [Zn<sub>14</sub>(hmq)<sub>8</sub>(OH)<sub>4</sub>Cl<sub>10</sub>]<sup>2ā</sup>. Because the supramolecular
interactions between the anion and cation in the solid suppress the
rotation/vibration of the halogen atoms and confine the movable organic
ligands on the rigid ZnāO core, both crystal phases exhibit
intense photoluminescence, much stronger than that in solution. This
is the first coordination cluster to exhibit āaggregation-induced
enhanced emissionā. In addition, preliminary tests indicate
that these coordination clusters are promising for organic-light-emitting-diode
applications
Xylazine Activates Adenosine Monophosphate-Activated Protein Kinase Pathway in the Central Nervous System of Rats
<div><p>Xylazine is a potent analgesic extensively used in veterinary and animal experimentation. Evidence exists that the analgesic effect can be inhibited using adenosine 5ā-monophosphate activated protein kinase (AMPK) inhibitors. Considering this idea, the aim of this study was to investigate whether the AMPK signaling pathway is involved in the central analgesic mechanism of xylazine in the rat. Xylazine was administrated via the intraperitoneal route. Sprague-Dawley rats were sacrificed and the cerebral cortex, cerebellum, hippocampus, thalamus and brainstem were collected for determination of liver kinase B1 (LKB1) and AMPKĪ± mRNA expression using quantitative real-time polymerase chain reaction (qPCR), and phosphorylated LKB1 and AMPKĪ± levels using western blot. The results of our study showed that compared with the control group, xylazine induced significant increases in AMPK activity in the cerebral cortex, hippocampus, thalamus and cerebellum after rats received xylazine (<i>P</i> < 0.01). Increased AMPK activities were accompanied with increased phosphorylation levels of LKB1 in corresponding regions of rats. The protein levels of phosphorylated LKB1 and AMPKĪ± in these regions returned or tended to return to control group levels. However, in the brainstem, phosphorylated LKB1 and AMPKĪ± protein levels were decreased by xylazine compared with the control (<i>P</i> < 0.05). In conclusion, our data indicates that xylazine alters the activities of LKB1 and AMPK in the central nervous system of rats, which suggests that xylazine affects the regulatory signaling pathway of the analgesic mechanism in the rat brain.</p></div
Effect of xylazine administration on the mRNA levels of LKB1 in rats.
<p>(A) Cerebral cortex, (B) Hippocampus, (C) Thalamus, (D) Cerebellum and (E) Brainstem. Rats received saline (0.5 mL) or xylazine (5.2 mg/kg) intraperitoneally and then were sacrificed 10, 10, 20, 40 or 60 min later for control, Xyl1, Xyl2, Xyl3 or Xyl4, respectively. Total RNA was isolated and subjected to real-time PCR analysis. Each value of the expression levels of LKB1 was normalized to the expression levels of Ī²-actin, and the control value was set to one. Data are presented as the means Ā± SEM, n = 6. * P < 0.05, ** P < 0.01 vs control.</p
Effect of xylazine administration on the levels of phosphorylated LKB1 in rats.
<p>(A) Cerebral cortex, (B) Hippocampus, (C) Thalamus, (D) Cerebellum and (E) Brainstem. Rats received saline (0.5 mL) or xylazine (5.2 mg/kg) intraperitoneally and then were sacrificed 10, 10, 20, 40 or 60 min later for control, Xyl1, Xyl2, Xyl3 or Xyl4, respectively. Western blot analyses were performed with anti-LKB1 and anti-phospho-LKB1 (Ser428). Data for densitometry represent the mean Ā± SEM obtained from six independent series of Western blotting for each animal group and time point after the procedure. * P < 0.05, ** P < 0.01 vs control. Representative blots are shown below graph.</p
Effect of xylazine administration on the mRNA levels of AMPKĪ±2 in rats.
<p>(A) Cerebral cortex, (B) Hippocampus, (C) Thalamus, (D) Cerebellum and (E) Brainstem. Rats received saline (0.5 mL) or xylazine (5.2 mg/kg) intraperitoneally and then were sacrificed 10, 10, 20, 40 or 60 min later for control, Xyl1, Xyl2, Xyl3 or Xyl4, respectively. Total RNA was isolated and subjected to real-time PCR analysis. Each value of the expression levels of AMPKĪ±2 was normalized to the expression levels of Ī²-actin, and the control value was set to one. Data are presented as the means Ā± SEM, n = 6. * P < 0.05, ** P < 0.01 vs control.</p
Effect of xylazine administration on the levels of phosphorylated AMPKĪ± in rats.
<p>(A) Cerebral cortex, (B) Hippocampus, (C) Thalamus, (D) Cerebellum and (E) Brainstem. Rats received saline (0.5 mL) or xylazine (5.2 mg/kg) intraperitoneally and then were sacrificed 10, 10, 20, 40 or 60 min later for control, Xyl1, Xyl2, Xyl3 or Xyl4, respectively. Western blot analyses were performed with anti-AMPKĪ± and anti-phosphor-AMPKĪ± (Thr172). Data for densitometry represent the mean Ā± SEM obtained from six independent series of Western blotting for each animal group and time point after the procedure. * P < 0.05, ** P < 0.01 vs control. Representative blots are shown below graph.</p