565 research outputs found
Power vs. Spectrum 2-D Sensing in Energy Harvesting Cognitive Radio Networks
Energy harvester based cognitive radio is a promising solution to address the
shortage of both spectrum and energy. Since the spectrum access and power
consumption patterns are interdependent, and the power value harvested from
certain environmental sources are spatially correlated, the new power dimension
could provide additional information to enhance the spectrum sensing accuracy.
In this paper, the Markovian behavior of the primary users is considered, based
on which we adopt a hidden input Markov model to specify the primary vs.
secondary dynamics in the system. Accordingly, we propose a 2-D spectrum and
power (harvested) sensing scheme to improve the primary user detection
performance, which is also capable of estimating the primary transmit power
level. Theoretical and simulated results demonstrate the effectiveness of the
proposed scheme, in term of the performance gain achieved by considering the
new power dimension. To the best of our knowledge, this is the first work to
jointly consider the spectrum and power dimensions for the cognitive primary
user detection problem
Proteomic Analysis of the Effect of Fuzheng Huayu Recipe on Fibrotic Liver in Rats
Hepatic fibrosis is a common pathological process of chronic liver diseases and would lead to cirrhosis, and Fuzheng Huayu (FZHY) is an effective Chinese herbal product against liver fibrosis. This study observes FZHY influence on proteome of fibrotic liver with differential proteomic approach and aims to understand FZHY multiple action mechanisms on liver fibrosis.
The liver fibrosis models were induced with intraperitoneal injection of dimethylnitrosamine for 4 weeks in rats and divided into model control (model) and FZHY-treated (FZHY) groups, while normal rats were used as normal control (normal). After model establishment, rats in FZHY groups were administered 4 g/kg wt of FZHY for 4 weeks, and normal and model groups were given the same volume of saline. The liver proteins in the above 3 groups were separated by two-dimensional gel electrophoresis (2-DE), the differentially expressed spots were analyzed and compared between normal and model or model and FZHY groups, and then the proteins were identified with mass spectrum analysis and validated partially with western blot and real-time PCR. 1000~1200 spots were displayed on each 2D gel, and a total of 61 protein spots were found with significant intensity difference between normal control or FZHY and model control. 23 most obviously differential spots were excised, and in-gel digestion and 21 peptide mass fingerprints (PMF) were obtained with MALDI-TOF MS analysis, and 14 proteins were identified through protein database searching. Among 14 differentially expressed proteins, 8 proteins in normal and FZHY groups had the same tendency of differential expression compared with the ones in model group. And one of them, vimentin, was validated by western blot and real-time PCR analyses. Our study reveals 12 proteins responsible for fibrogenesis induced by DMN in rats, and among them, 8 proteins in fibrotic liver were regulated by FZHY, including aldehyde dehydrogenase, vimentin isoform (CRA_b), gamma-actin, vimentin, fructose-bisphosphate aldolase B, aldo-keto reductase, S-adenosylhomocysteine hydrolase isoform, and HSP90. It indicates that the action mechanism of FZHY antiliver fibrosis may be associated with modulation of proteins associated with metabolism and stress response, as well as myofibroblast activation. The study provides new insights and data for exploring the liver fibrogenesis pathophysiology and FZHY action mechanism against liver fibrosis
BK channels of five different subunit combinations underlie the de novo KCNMA1 G375R channelopathy
The molecular basis of a severe developmental and neurological disorder associated with a de novo G375R variant of the tetrameric BK channel is unknown. Here, we address this question by recording from single BK channels expressed to mimic a G375R mutation heterozygous with a WT allele. Five different types of functional BK channels were expressed: 3% were consistent with WT, 12% with homotetrameric mutant, and 85% with three different types of hybrid (heterotetrameric) channels assembled from both mutant and WT subunits. All channel types except WT showed a marked gain-of-function in voltage activation and a smaller decrease-of-function in single-channel conductance, with both changes in function becoming more pronounced as the number of mutant subunits per tetrameric channel increased. The net cellular response from the five different types of channels comprising the molecular phenotype was a shift of -120 mV in the voltage required to activate half of the maximal current through BK channels, giving a net gain-of-function. The WT and homotetrameric mutant channels in the molecular phenotype were consistent with genetic codominance as each displayed properties of a channel arising from only one of the two alleles. The three types of hybrid channels in the molecular phenotype were consistent with partial dominance as their properties were intermediate between those of mutant and WT channels. A model in which BK channels randomly assemble from mutant and WT subunits, with each subunit contributing increments of activation and conductance, approximated the molecular phenotype of the heterozygous G375R mutation
Least Absolute Deviation Support Vector Regression
Least squares support vector machine (LS-SVM) is a powerful tool for pattern classification and regression estimation. However, LS-SVM is sensitive to large noises and outliers since it employs the squared loss function. To solve the problem, in this paper, we propose an absolute deviation loss function to reduce the effects of outliers and derive a robust regression model termed as least absolute deviation support vector regression (LAD-SVR). The proposed loss function is not differentiable. We approximate it by constructing a smooth function and develop a Newton algorithm to solve the robust model. Numerical experiments on both artificial datasets and benchmark datasets demonstrate the robustness and effectiveness of the proposed method
The chinese herbal decoction danggui buxue tang inhibits angiogenesis in a rat model of liver fibrosis.
In this study, we investigated the anti-angiogenic effect of the Chinese herbal decoction Danggui Buxue Tang (DBT; Radix Astragali and Radix Angelicae sinensis in 5 : 1 ratio) in a rat model of liver fibrosis, in order to elucidate its mechanisms of action against liver fibrosis. Liver fibrosis was induced with CCl(4) and high-fat food for 6 weeks, and the rats were treated with oral doses of DBT (6 g raw herbs/kg/d) and N-Acetyl-L-cysteine (NAC; 0.1 g/kg/d). The results showed that both DBT and NAC attenuated liver fibrosis and neo-angiogenesis. Furthermore, DBT and NAC improved SOD activity but decreased MDA content and 8-OH-dG in fibrotic livers, with DBT being more effective than NAC. DBT decreased the expression of VEGF, Ang1 and TGF-β1 and their signaling mediators, whereas NAC had no effect on VEGF and VEGFR2 expression. Both DBT and NAC reduced HIF-1α gene and protein expression in fibrotic livers, with DBT being more effective. These data clearly demonstrate that the anti-fibrotic properties of DBT are related to its ability to inhibit angiogenesis and its anti-angiogenic mechanisms are associated with improving oxidative stress, regulating the expression and signaling of angiogenic factors, and especially modulating HIF-1α in fibrotic livers
Pelvic infection caused by periodontitis: A case report
Oral bacteria in patients with periodontitis can disseminate into the bloodstream via broken oral epithelial cells, causing odontogenic maxillofacial infections, brain abscesses and endocarditis. However, pelvic infection caused by periodontitis is rare. The case of a 48-year-old woman with a long history of recurrent periodontal infections, who complained of abdominal distention and pain for 14 days after dental implantation, is reported here. Pelvic ultrasound and magnetic resonance imaging signaled multiple inflammatory encapsulated effusions in the posterior uterus, which were removed by laparoscopic surgery and tested with metagenomic next-generation sequencing (mNGS). Through mNGS, numerous oral pathogens, including Filifactor alocis, were identified in the pelvic effusions. The patient was subsequently diagnosed with a pelvic infection originating from periodontitis, and recovered after undergoing surgery and targeted antibacterial treatment. Thus, the possibility of extrabuccal complications in patients with a history of periodontitis or invasive oral procedures merits closer attention
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