83 research outputs found
Primary Age-Related Tauopathy in Human Subcortical Nuclei
The present study aimed to determine the spatial distribution patterns of hyperphosphorylated tau-immunoreactive cells in subcortical nuclei of post-mortem human brain with primary age-related tauopathy (PART). Subcortical tauopathy has important pathological and clinical implications. Expression of tau was examined in different subcortical regions of definite PART cases with a Braak neurofibrillary tangle stage >0 and ≤IV, and with a Thal phase 0 (no beta-amyloid present). Post-mortem brain tissue of PART was studied using immunohistochemistry and subsequent semi-quantitative assessment with Braak NFT stage -matched pre-Alzheimer’s disease (AD) and AD cases as a control. Expression of tau was frequently found in subcortical nuclei including the substantia nigra, inferior colliculus, locus coeruleus, medulla oblongata in the brainstem, the caudate, putamen, nucleus globus pallidus in the striatum, the hypothalamus, thalamus, subthalamus in the diencephalon, and the cervical spinal cord in both PART and AD, but not in the dentate nucleus of the cerebellum. A positive correlation was found between the Braak NFT stage and the tau distribution (qualitative)/tau density (quantitative) in PART and AD. Brainstem nuclei were commonly involved in early PART with NFT Braak stage I/II, there was no preference among the substantia nigra, inferior colliculus, locus caeruleus and medulla oblongata. The prevalence and severity of tau pathology in subcortical nuclei of PART and AD were positively correlated with NFT Braak stage, suggesting that these nuclei were increasingly involved as PART and AD progressed. Subcortical nuclei were likely the sites initially affected by aging associated tau pathology, especially the brainstem nuclei including the substantia nigra, inferior colliculus, locus caeruleus and medulla oblongata
Selective Down-Regulation of Nuclear Poly(ADP-Ribose) Glycohydrolase
The formation of ADP-ribose polymers on target proteins by poly(ADP-ribose) polymerases serves a variety of cell signaling functions. In addition, extensive activation of poly(ADP-ribose) polymerase-1 (PARP-1) is a dominant cause of cell death in ischemia-reperfusion, trauma, and other conditions. Poly(ADP-ribose) glycohydrolase (PARG) degrades the ADP-ribose polymers formed on acceptor proteins by PARP-1 and other PARP family members. PARG exists as multiple isoforms with differing subcellular localizations, but the functional significance of these isoforms is uncertain.Primary mouse astrocytes were treated with an antisense phosphorodiamidate morpholino oligonucleotide (PMO) targeted to exon 1 of full-length PARG to suppress expression of this nuclear-specific PARG isoform. The antisense-treated cells showed down-regulation of both nuclear PARG immunoreactivity and nuclear PARG enzymatic activity, without significant alteration in cytoplasmic PARG activity. When treated with the genotoxic agent MNNG to induced PARP-1 activation, the antisense-treated cells showed a delayed rate of nuclear PAR degradation, reduced nuclear condensation, and reduced cell death.These results support a preferentially nuclear localization for full-length PARG, and suggest a key role for this isoform in the PARP-1 cell death pathway
Reactive astrocytes undergo M1 microglia/macrohpages-induced necroptosis in spinal cord injury
Inspection of reinforced concrete interface delamination using embedded piezoelectric actuators/sensors
The interface between concrete and steel in reinforced concrete governs the interaction between the two types of materials under loading. When the interface is seriously damaged, such that a macro-crack is formed, de-bonding takes place or large slip occurs, and the load-transferring capacity of the interface will drop dramatically. The study is to present a novel technique to detect the delamination at the interface between the reinforcing steel bar and concrete using guided waves. The piezoelectric components are mounted on reinforcing bars that embedded in RC structures as sensors and actuators to generate the signal, which is sensitive to the delamination between the steel bars and concrete. The experimental study is carried out on a concrete slab with different debonds between the rebars and concrete. Two parameters are calculated from the measured responses and used to indicate the debonding damage. The test results show that the delamination between the rebars and concrete can be detected with the embedded piezoelectric sensors and actuators
Influences of Online Teaching Ability of University Teachers on Learning Engagement of Learners
Abstract—Due to advances in education and informatics, online learning is now becoming a direction for teaching reform in universities. This in turn put learning engagement at the forefront of educational literature: online teaching activity has become a key component of teaching due to its strong influence on learning engagement and outcomes. This study analyzes the influences of teachers’ online teaching ability (teaching design ability, resource development ability, teaching implementation ability, teaching evaluation ability, teaching reflection ability) on learning engagement across different majors and grade-levels. Research results showed abilities on teaching design, teaching implementation, teaching evaluation, and teaching reflection have significantly positive influences on learning engagement. These results provide important references in further exploring influencing mechanism of teaching activities on learning engagement, improve online teaching ability of teachers, and increase online learning engagement of students
RNAi Rab27a inhibited C6 glioma cell migration and invasion in transwell experiments (with or without ECM gel).
<p>A. Images of cells on the undersurface of a filter without ECM gel, either untreated (control) or treated with Rab27a shRNA or Rab27a siRNA, showing that the number of cells decreased. B. Quantification of the transwell assays. The surface area for samples treated with Rab27a shRNA was 80.53±3.06%, and with Rab27A siRNA was 85.40±6.94% (p<0.01). C. Images of cells on the undersurface of a filter with ECM gel, either untreated (control) or treated with Rab27a shRNA or Rab27a siRNA, showing that the number of cells decreased. D. Quantification of the transwell assays. The change in the surface area for samples treated with Rab27a shRNA was 63.89±8.49%, and with Rab27a siRNA was 36.04±6.59% (p<0.01). Bars represent the average ± S.E., n≥3. Magnification, ×20.</p
Spin scattering effect on thermal transport and nonadiabatic small polaron hopping conduction in layered cobaltite thin film
China-MOST [2008DFA51230]; National Key Basic Science Research Program (973 Project) [2007CB936603]; NSFC [11074207, 60776007]; Xiamen University [X12111]Transport properties in the a-b plane of Nd(0.75)Sr(1.25)CoO(4) thin film as fabricated via a pulsed laser deposition technique have been investigated by means of measurements of resistivity and thermopower, respectively, in the temperature ranges of 76-300 and 80-310 K. The thermopower of the specimen revealed a mechanism of spin-dependent scattering of the charge carriers where its conduction could be well interpreted by the small polaron hopping conduction in the nonadiabatic regime at high temperatures and the two-dimensional variable range hopping of small polarons at low temperatures. Possible mechanisms for the polaronic conduction were also discussed in the article where several physical parameters of the specimen were determined using a small polaron hopping model and a better understanding of the strongly correlated electron system was achieved
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