2,297 research outputs found
4-Nitrophenyl N-phenylcarbamate
The title compound, C13H10N2O4, was synthesized as an intermediate for the preparation of ureas. The two aromatic rings are twisted about the central carbamate group with a C—C—N—C torsion angle of 139.6 (2)° and a C—C—O—C torsion angle of 95.9 (2)°. The molecules are linked into one-dimensional chains by N—H⋯O hydrogen bonds along the b axis. Weak interactions between O atoms of the nitro groups (O⋯O = 3.012 Å) connect two adjacent chains
5-Methyl-1,2,3,3a-tetrahydrobenzo[e]pyrrolo[2,1-b][1,3]oxazepin-10(5H)-one
The asymmetric unit of the title compound, C13H15NO2, the main product of a photoreaction, contains two crystallographically independent molecules. In both molecules, the conformation of the seven-membered ring is twist sofa and that of the five-membered rings is envelope. In the crystal, molecules are linked by weak intermolecular C—H⋯O hydrogen bonds
Epileptiform discharge upregulates p-ERK1/2, growth-associated protein 43 and synaptophysin in cultured rat hippocampal neurons
AbstractExtracellular signal-regulated protein kinase, ERK1/2 is activated by phosphorylation (p-ERK1/2) during environmental stress such as epileptiform discharge. We investigated the role of ERK1/2 in abnormal axon growth and synapse reorganization in cultured neurons displaying epileptiform activity.The cultured neurons displaying epileptiform activity were treated with magnesium-free extracellular fluid for 3h and monitored epileptiform discharges using whole-cell patch clamp. Two study groups, neurons displaying epileptiform activity and the same neurons treated with ERK1/2 inhibitor U0126, were studied at six time points, 0min, 30min, 2h, 6h, 12h, and 24h following discharge. The expressions of p-ERK1/2, C-fos, growth-associated protein 43 (GAP-43) and synaptophysin (SYP), as markers of axon growth and synapse reorganization, were investigated by double-label immunofluorescence and western blotting.In the neurons displaying epileptiform activity, p-ERK1/2 was detected immediately following discharge, and expression peaked at 30min. The expression of C-fos, GAP-43 and SYP followed the same pattern as p-ERK1/2. In the treated group, p-ERK1/2 was inhibited completely, and C-fos, GAP-43 and SYP were reduced.These findings indicate that epileptiform discharge activates ERK1/2 which regulates C-fos in cultured neurons displaying epileptiform activity, and this cascade may upregulate GAP-43 and SYP to contribute to axon growth and synapse reorganization to potentiate epileptic activities
Late cardioprotection of exercise preconditioning against exhaustive exercise-induced myocardial injury by up-regulatation of connexin 43 expression in rat hearts
AbstractObjectiveTo investigate the expression of myocardium connexin 43 (Cx43) in late exercise preconditioning (LEP) cardioprotection.MethodsEight-week-old adult male Sprague Dawley rats were randomly assigned into four groups (n = 8). Myocardial injury was judged in accordance with serum levels of cTnⅠ and NT-proBNP as well as hematoxylin basicfuchsin picric acid staining of myocardium. Cx43 mRNA was detected by in situ hybridization and qualified by real-time fluorescence quantitative PCR. Cx43 protein was localized by immunohistochemistry and its expression level was determined by western blotting.ResultsThe LEP obviously attenuated the myocardial ischemia/hypoxia injury caused by exhaustive exercise. There was no significant difference of Cx43 mRNA level between the four groups. Cx43 protein level was decreased significantly in group EE (P < 0.05). However, LEP produced a significant increase in Cx43 protein level (P < 0.05), and the decreased Cx43 protein level in exhaustive exercise was significantly up-regulated by LEP (P < 0.05).ConclusionsLEP protects rat heart against exhaustive exercise-induced myocardial injury by up-regulating the expression of myocardial Cx43
Different cerebral plasticity of intrinsic and extrinsic hand muscles after peripheral neurotization in a patient with brachial plexus injury: A TMS and fMRI study
AbstractContralateral C7 (CC7) neurotization has been an important approach for brachial plexus injury (BPI). Patients can achieve relatively good grasping function driven by the proximal extrinsic hand muscle (flexor digitorum, FD) after CC7 neurotization, whereas the thumb opposition function driven by the distal intrinsic muscle (abductor pollicis brevis, APB) is poor. The present study aimed to investigate the brain reorganization patterns of the recovery processes of intrinsic and extrinsic hand functions after repairing the median nerve by CC7 neurotization. Transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) were used to evaluate the cerebral plasticity in one BPI patient after CC7 neurotization. After the CC7 neurotization, the patient showed improvements in the paralyzed hand. Combination of TMS and fMRI investigations demonstrated different cortical reshaping patterns of APB and FD. It was also found that the activated cortical areas of FD were located in bilateral motor cortices, but the area of APB was only located in ipsilateral motor cortex. The cerebral plasticity procedure appeared to be different in the gross and fine motor function recovery processes. It provided a new perspective into the cerebral plasticity induced by CC7 neurotization
An efficient DNA isolation method for tropical plants
Due to interfering components such as polysacharrides, polyphenols, etc, DNA isolation from tropical plants had been challenging. We developed a safe, universal and efficient DNA extraction method, which yielded high-quality DNA from 10 tropical plants including cassava, rubber tree, banana, etc. In the extraction buffer, 2 M NaCl was used to provide a high ionic strength reaction environment, ethylenediaminetetraacetic acid (EDTA), lauroyl sarcosine (LSS) and cetyl trimethyl ammonium bromide (CTAB) could inhibit DNase activity effectively, polyvinylpolypyrrolidone (PVPP) produced a deoxidized reaction environment, and borax enhanced the precipitation of interfering compounds. Ordinary reagents like β-mercaptoethanol, chloroform and phenol were unnecessary in this protocol, which made it safe and friendly to use. PCR and EcoR I enzyme restriction digestion results show that the obtained DNA is good enough for downstream analysis. In conclusion, this protocol is expected to be a preferable DNA extraction protocol for tropical plants.Keywords: DNA extraction, tropical plants, cetyl trimethyl ammonium bromide (CTAB)African Journal of Biotechnology Vol. 12(19), pp. 2727-273
1,2-Bis(4-nitrobenzoyl)hydrazine
The title molecule, C14H10N4O6, crystallizes with one half-molecule in the asymmetric unit; the mid-point of the N—N bond lies on an inversion centre. The nitro and amide groups are twisted with respect to the benzene ring, making dihedral angles of 14.6 (5) and 31.1 (5)°, respectively. In the crystal structure, molecules are linked through N—H⋯O hydrogen bonding between the imino and carbonyl groups
Topological transitions in continuously-deformed photonic crystals
We demonstrate that multiple topological transitions can occur, with
high-sensitivity, by continuous change of the geometry of a simple 2D
dielectric-frame photonic crystal consisting of circular air-holes. By changing
the radii of the holes and/or the distance between them, multiple transitions
between normal and topological photonic band gaps (PBGs) can appear. The
time-reversal symmetric topological PBGs resemble the quantum spin-Hall
insulator of electrons and have two counter-propagating edge states. We search
for optimal topological transitions, i.e., sharp transitions sensitive to the
geometry, and optimal topological PBGs, i.e., large PBGs with clean spectrum of
edge states. Such optimizations reveal that dielectric-frame photonic crystals
are promising for optical sensors and unidirectional waveguides.Comment: submitted to Phys. Rev.
- …