3,406 research outputs found
Danshen-Chuanxiong-Honghua Ameliorates Cerebral Impairment and Improves Spatial Cognitive Deficits after Transient Focal Ischemia and Identification of Active Compounds.
Previously, we only apply a traditional Chinese medicine (TCM) Danshen-Chuanxiong-Honghua (DCH) for cardioprotection via anti-inflammation in rats of acute myocardial infarction by occluding coronary artery. Presently, we select not only DCH but also its main absorbed compound ferulic acid (FA) for cerebra protection via similar action of mechanism above in animals of the transient middle cerebral artery occlusion (tMCAO). We investigated whether oral administration of DCH and FA could ameliorate MCAO-induced brain lesions in animals. By using liquid chromatography-tandem mass spectrometry (LC-MS/MS), we analyzed four compounds, including tanshinol, salvianolic acid B, hydroxysafflor yellow A and especially FA as the putative active components of DCH extract in the plasma, cerebrospinal fluid and injured hippocampus of rats with MCAO. In our study, it was assumed that FA played a similar neuroprotective role to DCH. We found that oral pretreatment with DCH (10 or 20 g/kg) and FA (100 mg/kg) improved neurological function and alleviated the infarct volume as well as brain edema in a dose-dependent manner. These changes were accompanied by improved ischemia-induced apoptosis and decreased the inflammatory response. Additionally, chronic treatment with DCH reversed MCAO-induced spatial cognitive deficits in a manner associated with enhanced neurogenesis and increased the expression of brain-derived neurotrophic factor in lesions of the hippocampus. These findings suggest that DCH has the ability to recover cognitive impairment and offer neuroprotection against cerebral ischemic injury via inhibiting microenvironmental inflammation and triggering of neurogenesis in the hippocampus. FA could be one of the potential active compounds
Magnetization Dynamics in Synthetic Antiferromagnets with Perpendicular Magnetic Anisotropy
Understanding the rich physics of magnetization dynamics in perpendicular
synthetic antiferromagnets (p-SAFs) is crucial for developing next-generation
spintronic devices. In this work, we systematically investigate the
magnetization dynamics in p-SAFs combining time-resolved magneto-optical Kerr
effect (TR-MOKE) measurements with theoretical modeling. These model analyses,
based on a Landau-Lifshitz-Gilbert approach incorporating exchange coupling,
provide details about the magnetization dynamic characteristics including the
amplitudes, directions, and phases of the precession of p-SAFs under varying
magnetic fields. These model-predicted characteristics are in excellent
quantitative agreement with TR-MOKE measurements on an asymmetric p-SAF. We
further reveal the damping mechanisms of two procession modes co-existing in
the p-SAF and successfully identify individual contributions from different
sources, including Gilbert damping of each ferromagnetic layer, spin pumping,
and inhomogeneous broadening. Such a comprehensive understanding of
magnetization dynamics in p-SAFs, obtained by integrating high-fidelity TR-MOKE
measurements and theoretical modeling, can guide the design of p-SAF-based
architectures for spintronic applications.Comment: 24 pages, 5 figure
Identify submitochondria and subchloroplast locations with pseudo amino acid composition: Approach from the strategy of discrete wavelet transform feature extraction
AbstractIt is very challenging and complicated to predict protein locations at the sub-subcellular level. The key to enhancing the prediction quality for protein sub-subcellular locations is to grasp the core features of a protein that can discriminate among proteins with different subcompartment locations. In this study, a different formulation of pseudoamino acid composition by the approach of discrete wavelet transform feature extraction was developed to predict submitochondria and subchloroplast locations. As a result of jackknife cross-validation, with our method, it can efficiently distinguish mitochondrial proteins from chloroplast proteins with total accuracy of 98.8% and obtained a promising total accuracy of 93.38% for predicting submitochondria locations. Especially the predictive accuracy for mitochondrial outer membrane and chloroplast thylakoid lumen were 82.93% and 82.22%, respectively, showing an improvement of 4.88% and 27.22% when other existing methods were compared. The results indicated that the proposed method might be employed as a useful assistant technique for identifying sub-subcellular locations. We have implemented our algorithm as an online service called SubIdent (http://bioinfo.ncu.edu.cn/services.aspx)
In-situ tuning of catalytic activity by thermoelectric effect for ethylene oxidation
Thermoelectric material BiCuSeO used as a support and promoter for catalytic ethylene oxidation is reported here. The catalytic activity on the continuous and non-continuous catalyst Pt supported on BiCuSeO was observed to be promoted in-situ by a thermoelectric Seebeck voltage generated by the temperature gradient across the material. It is also shown this thermoelectric promotion of catalysis enabled the thermoelectric material BiCuSeO itself to be highly catalytic active for ethylene oxidation. A good linear relationship between the logarithm of the reaction rate and the thermoelectric Seebeck voltage was observed. This thermoelectric promotion of catalysis is attributed to the change of work function of the catalyst surface, accompanied by a charge transfer from the bulk to the surface due to the thermoelectric effect
Towards harmonious East-West educational partnerships: a study of cultural differences between Taiwanese and Norwegian engineering students
The collaboration activities between educational
institutions in the East and the West are on the
increase as an increasingly globalized economy requires
graduates to have the skills to work across cultural divides.
Such collaborations are difficult and require patience. One
challenge is that students or teachers may have misconceptions
about aspects of the other culture that may cause
problems. This study sets out to identify what values students
in typical Eastern and Western societies associate
with a good student, good student behavior, good teachers
and good lectures with the purpose to identify discrepancies.
This study is based on the results of a pair-wise
ranking questionnaire completed by 233 Taiwanese and
Norwegian students of both engineering and non-technical
subjects. The results confirm some established beliefs
regarding culturally related differences. However, several
issues were found to be culturally neutral, and cultural
differences were identified for several issues that were
predicted to be culturally neutral. The results of this study
may be useful to educators involved in East–West
internationalization
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