9,493 research outputs found
Bottom-Up versus Top-Down Induction of Sleep by Zolpidem Acting on Histaminergic and Neocortex Neurons
Zolpidem, a GABAA receptor-positive modulator, is the gold-standard drug for treating insomnia. Zolpidem prolongs IPSCs to decrease sleep latency and increase sleep time, effects that depend on α2 and/or α3 subunit-containing receptors. Compared with natural NREM sleep, zolpidem also decreases the EEG power, an effect that depends on α1 subunit-containing receptors, and which may make zolpidem-induced sleep less optimal. In this paper, we investigate whether zolpidem needs to potentiate only particular GABAergic pathways to induce sleep without reducing EEG power. Mice with a knock-in F77I mutation in the GABAA receptor γ2 subunit gene are zolpidem-insensitive. Using these mice, GABAA receptors in the frontal motor neocortex and hypothalamic (tuberomammillary nucleus) histaminergic-neurons of γ2I77 mice were made selectively sensitive to zolpidem by genetically swapping the γ2I77 subunits with γ2F77 subunits. When histamine neurons were made selectively zolpidem-sensitive, systemic administration of zolpidem shortened sleep latency and increased sleep time. But in contrast to the effect of zolpidem on wild-type mice, the power in the EEG spectra of NREM sleep was not decreased, suggesting that these EEG power-reducing effects of zolpidem do not depend on reduced histamine release. Selective potentiation of GABAA receptors in the frontal cortex by systemic zolpidem administration also reduced sleep latency, but less so than for histamine neurons. These results could help with the design of new sedatives that induce a more natural sleep
Classification of Chest Diseases using Wavelet Transforms and Transfer Learning
Chest X-ray scan is a most often used modality by radiologists to diagnose
many chest related diseases in their initial stages. The proposed system aids
the radiologists in making decision about the diseases found in the scans more
efficiently. Our system combines the techniques of image processing for feature
enhancement and deep learning for classification among diseases. We have used
the ChestX-ray14 database in order to train our deep learning model on the 14
different labeled diseases found in it. The proposed research shows the
significant improvement in the results by using wavelet transforms as
pre-processing technique.Comment: 8 pages, 4 figures, Presented in International Conference On Medical
Imaging And Computer-Aided Diagnosis (MICAD 2020), proceeding will be
published with Springer in their "Lecture Notes in Electrical Engineering
(LNEE)" (ISSN: 1876-1100
Electrical reliability and leakage mechanisms in highly resistive multiferroic La0.1Bi0.9FeO3 ceramics
Multiferroic La0.1 Bi0.9 FeO3 (LBFO) ceramics with high resistivity were synthesized by using a modified rapid thermal process. The LBFO ceramics show very low leakage and low dielectric loss. Well saturated ferroelectric hysteresis loops and polarization switching currents have been observed. For a maximum applied electric field of 145 kV/cm, the remanent polarization is 17.8 μC/ cm2 and the coercive filed is 75 kV/cm. The dominant conduction mechanism in the LBFO ceramics has been found to be the space-charge-limited current mechanism rather than the thermal excitation mechanism. Electrical reliability related to the fatigue and polarization retention of the LBFO ceramics has also been discussed with the leakage mechanisms. © 2011 American Institute of Physics.published_or_final_versio
Increased expression of cyclooxygenase-2 in first-degree relatives of gastric cancer patients
Aim: To study the expression of cyclooxygenase-2 (COX-2) in human gastric cancer tissues and their paired adjacent mucosa, as well as mucosa from gastric antrum and corpus of the first-degree relatives of the recruited cancer patients. Methods: The expression of COX-2 mRNA in 38 patients with gastric cancer and their 29 first-degree relatives and 18 healthy controls was assessed by the real time RT-PCR. The expression of COX-2 protein was determined by Western blot. Results: A marked increase in COX-2 mRNA expression was found in 20 of 37 (54%) cancerous tissues compared to their respective paired normal mucosa (P<0.001). Interestingly, increased COX-2 mRNA expression was also found in mucosa of the corpus (6/29) and antrum (13/29) of their first-degree relatives. Increased COX-2 mRNA expression was more frequently observed in the antrum biopsies from cancer patients than in the antrum biopsies from healthy controls (P<0.05). In addition, 3 of 23 (13%) patients with atrophic mucosa and 6 of 35 (17%) patients with intestinal metaplasia showed increased COX-2 mRNA expression. Furthermore, COX-2 expression increased in H pylori-positive tissues, especially in antrum mucosa. Conclusion: Increased COX-2 expression is involved in gastric carcinogenesis, and may be necessary for maintenance of the malignant phenotype and contribute to Helicobacter pylori-associated malignant transformation. © 2005 The WJG Press and Elsevier Inc. All rights reserved.published_or_final_versio
Resistive switching and threshold switching behaviors in La 0.1Bi 0.9Fe 1-xCo xO 3 ceramics
The effects of cobalt doping on the electrical conductivity of La 0.1Bi 0.9Fe 1-xCo xO 3 (LBFCO, x=0, 0.01, 0.03) ceramics were investigated. It is found that the leakage current increases with cobalt dopant concentration in LBFCO. On the application of bias voltage LBFCO ceramics with cobalt doping exhibits resistive switching effects at room temperature and threshold switching effects at elevated temperatures (50°C and 80°C). X-ray photoelectron spectroscopy of LBFCO ceramics show that cobalt dopant is bivalent as an acceptor, which induces an enhancement of oxygen vacancy concentration in LBFCO ceramics. Possible mechanisms for both resistive switching and threshold switching effects are discussed on the basis of the interplay of bound ferroelectric charges and mobile charged defects. © 2012 American Institute of Physics.published_or_final_versio
ABCD Neurocognitive Prediction Challenge 2019: Predicting individual residual fluid intelligence scores from cortical grey matter morphology
We predicted residual fluid intelligence scores from T1-weighted MRI data
available as part of the ABCD NP Challenge 2019, using morphological similarity
of grey-matter regions across the cortex. Individual structural covariance
networks (SCN) were abstracted into graph-theory metrics averaged over nodes
across the brain and in data-driven communities/modules. Metrics included
degree, path length, clustering coefficient, centrality, rich club coefficient,
and small-worldness. These features derived from the training set were used to
build various regression models for predicting residual fluid intelligence
scores, with performance evaluated both using cross-validation within the
training set and using the held-out validation set. Our predictions on the test
set were generated with a support vector regression model trained on the
training set. We found minimal improvement over predicting a zero residual
fluid intelligence score across the sample population, implying that structural
covariance networks calculated from T1-weighted MR imaging data provide little
information about residual fluid intelligence.Comment: 8 pages plus references, 3 figures, 2 tables. Submission to the ABCD
Neurocognitive Prediction Challenge at MICCAI 201
The Species of Rhimphoctona (Xylophylax) (Hymenoptera: Ichneumonidae: Campopleginae) Parasitizing Woodborers in China
Four species of Rhimphoctona (Xylophylax) collected from P. R. China are reported. Two of them are new to science: Rhimphoctona (Xylophylax) maculifemoralis Luo and Sheng, sp.nov. reared from Tetropium castaneum (Linnaeus), and Rhimphoctona (Xylophylax) immaculata Luo and Sheng, sp.nov. One is a new record for China, R. (Xylophylax) rufocoxalis (Clément 1924) reared from T. castaneum (Linnaeus). The other is R. (Xylophylax) lucida (Clément 1924) reared from Monochamus saltuarius Gebier, Tetropium gabrieli Weise and Asemus sp. A key to species known in China is provided
Mitochondrial transfer of mesenchymal stem cells effectively protects corneal epithelial cells from mitochondrial damage
published_or_final_versio
On a fabric evolution law incorporating the effects of b-value
In this paper, the effects of the intermediate stress ratio, i.e., b-value (b = (σ₂ − σ₃)/(σ₁ − σ₃)), on the contact normal-based fabric evolution of granular material, are incorporated into an extant hybrid fabric evolution law. The new evolution law is validated by Discrete Element Method (DEM) simulation results under monotonic shearing with different b-values. Predictions of the proposed generalized fabric evolution law agree well with the DEM simulation results. This evolution law can be widely used for constitutive modelling of granular materials, considering the effects of b-value in a general geomechanical three-dimensional stress space
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