2,595 research outputs found
An integral sliding-mode parallel control approach for general nonlinear systems via piecewise affine linear models
The fundamental problem of stabilizing a general nonaffine continuous-time
nonlinear system is investigated via piecewise affine linear models (PALMs) in
this article. A novel integral sliding-mode parallel control (ISMPC) approach
is developed, where an uncertain piecewise affine system (PWA) is constructed
to model a nonaffine continuous-time nonlinear system equivalently on a compact
region containing the origin. A piecewise sliding-mode parallel controller is
designed to globally stabilize the PALM and, consequently, to semiglobally
stabilize the original nonlinear system. The proposed scheme enjoys three
favorable features: (i) some restrictions on the system input channel are
eliminated, thus the developed method is more relaxed compared with the
published approaches; (ii) it is convenient to be used to deal with both
matched and unmatched uncertainties of the system; and (iii) the proposed
piecewise parallel controller generates smooth control signals even around the
boundaries between different subspaces, which makes the developed control
strategy more implementable and reliable. Moreover, we provide discussions
about the universality analysis of the developed control strategy for two kinds
of typical nonlinear systems. Simulation results from two numerical examples
further demonstrate the performance of the developed control approach
ATASI-Net: An Efficient Sparse Reconstruction Network for Tomographic SAR Imaging with Adaptive Threshold
Tomographic SAR technique has attracted remarkable interest for its ability
of three-dimensional resolving along the elevation direction via a stack of SAR
images collected from different cross-track angles. The emerged compressed
sensing (CS)-based algorithms have been introduced into TomoSAR considering its
super-resolution ability with limited samples. However, the conventional
CS-based methods suffer from several drawbacks, including weak noise
resistance, high computational complexity, and complex parameter fine-tuning.
Aiming at efficient TomoSAR imaging, this paper proposes a novel efficient
sparse unfolding network based on the analytic learned iterative shrinkage
thresholding algorithm (ALISTA) architecture with adaptive threshold, named
Adaptive Threshold ALISTA-based Sparse Imaging Network (ATASI-Net). The weight
matrix in each layer of ATASI-Net is pre-computed as the solution of an
off-line optimization problem, leaving only two scalar parameters to be learned
from data, which significantly simplifies the training stage. In addition,
adaptive threshold is introduced for each azimuth-range pixel, enabling the
threshold shrinkage to be not only layer-varied but also element-wise.
Moreover, the final learned thresholds can be visualized and combined with the
SAR image semantics for mutual feedback. Finally, extensive experiments on
simulated and real data are carried out to demonstrate the effectiveness and
efficiency of the proposed method
Effect of rosiglitazone on rabbit model of myocardial ischemia-reperfusion injury
AbstractObjectiveTo explore mechanism and protective effect of rosiglitazone on myocardial ischemia reperfusion (I/R) injury.MethodsA total of 48 male Japanese white big-ear rabbits were randomly divided into control group (A), I/R group (B), low dose of rosiglitazone group (C), high dose of rosiglitazone group (D). Plasma concentration of and also reduced the concentration of plasma serum creatine kinase (CK), CK-MB, high-sensitivity C-reactive protein (hsCRP), ultra-superoxide dismutase (SOD), malondialdehyde (MDA), lactic acid glutathione skin peroxidase (GSH-PX), nitric oxide (NO) and endothelin (ET) were measured 1 h later after I/R. Twenty-four hours after I/R the hearts were harvested for pathological and ultrastructural analysis. Area of myocardial infarction were tested.ResultsPlasma concentration of CK, CK-MB, hsCRP, NO, MDA and ET were decreased in C, D group compared with group B. Plasma concentration of T-SOD and GSH-Px were increased significantly in C, D group compared with group B. Compared with group B, pathological and ultrastructural changes in C and D group were slightly. There was significant difference in myocardial infarction area between group C, D and group B (P<0.05). Myocardial infarction area and arrhythmia rate were lower in group C, D compare with group B.ConclusionsRosiglitazone may protect myocardium from I/R injury by enhancing T-SOD and GSH-Px concentration, inhibit inflammatory reaction, and improve endothelial function
Repeated Aconitine Treatment Induced the Remodeling of Mitochondrial Function via AMPK–OPA1–ATP5A1 Pathway
Aconitine is attracting increasing attention for its unique positive inotropic effect on the cardiovascular system, but underlying molecular mechanisms are still not fully understood. The cardiotonic effect always requires abundant energy supplement, which is mainly related to mitochondrial function. And OPA1 has been documented to play a critical role in mitochondrial morphology and energy metabolism in cardiomyocytes. Hence, this study was designed to investigate the potential role of OPA1-mediated regulation of energy metabolism in the positive inotropic effect caused by repeated aconitine treatment and the possible mechanism involved. Our results showed that repeated treatment with low-doses (0–10 μM) of aconitine for 7 days did not induce detectable cytotoxicity and enhanced myocardial contraction in Neonatal Rat Ventricular Myocytes (NRVMs). Also, we first identified that no more than 5 μM of aconitine triggered an obvious perturbation of mitochondrial homeostasis in cardiomyocytes by accelerating mitochondrial fusion, biogenesis, and Parkin-mediated mitophagy, followed by the increase in mitochondrial function and the cellular ATP content, both of which were identified to be related to the upregulation of ATP synthase α-subunit (ATP5A1). Besides, with compound C (CC), an inhibitor of AMPK, could reverse aconitine-increased the content of phosphor-AMPK, OPA1, and ATP5A1, and the following mitochondrial function. In conclusion, this study first demonstrated that repeated aconitine treatment could cause the remodeling of mitochondrial function via the AMPK–OPA1–ATP5A1 pathway and provide a possible explanation for the energy metabolism associated with cardiotonic effect induced by medicinal plants containing aconitine
Neighbourhood satisfaction in rural resettlement residential communities: the case of Suqian, China
Against the background of large-scale urbanisation and rural land expropriation, rural resettlement residential housing has been built to accommodate local rural residents in the peripheral areas of China. To explore the context-specific policy implications for improving neighbourhood satisfaction (NS) of residents in rural resettlement residential communities (RRRCs), this paper examines the determinants of NS, and their spatial effects, in rural resettlement residential neighbourhoods using Suqian, in Jiangsu Province, as a case study. This study contributes to the current literature in two ways: it constitutes the first attempt to examine NS among RRRCs; second, our spatial model helps to gain further understanding of horizontal and vertical spatial dependence effects. Our results indicate that income, gender, age, family structure, number of years living in a community, transport and architectural age all have significant effects on NS in RRRCs
Toll-like receptor 9 interaction with CpG ODN – An in silico analysis approach
BACKGROUND: Toll-like receptor 9 (TLR9) recognises unmethylated CpG DNA and activates a signalling cascade, leading to the production of inflammatory cytokines such as TNF-α, IL-1, IL-6 and IL-12 via the adaptor protein MyD88. However, the specific sequence and structural requirements of the CpG DNA for the recognition of and binding to TLR9 are unknown. Moreover, the 3D structures of TLR9 and the TLR9-ODN complex have not been determined. In this study, we propose a reliable model of the interaction of the TLR9 ECD with CpG ODN using bioinformatics tools. RESULTS: The three-dimensional structures of two TLR9 ECD-CpG ODN complexes were constructed using a homology modelling and docking strategy. Based on the models of these complexes, the TLR9 ECD-CpG ODN interaction patterns were calculated. The results showed that the interface between the human TLR9 and the CpG ODN molecule is geometrically complementary. The computed molecular interactions indicated that LRR11 is the main region of TLR9 that binds to CpG ODN and that five positively charged residues within LRR11 are involved in the binding of the TLR9 ECD to the CpG ODN. Observations in the close-up view of these interactions indicated that these five positively charged residues contribute differently to the binding region within the TLR9 ECD-CpG ODN complex. 337Arg and 338Lys reside in the binding sites of ODN, forming hydrogen bonds and direct contacts with the CpG ODN, whereas 347Lys, 348Arg, and 353His do not directly contact the CpG ODN. These results are in agreement with previously reported experimental data. CONCLUSION: In this study, we present two structural models for the human and mouse TLR9 ECD in a complex with CpG ODN. Some features predicted by this model are consistent with previously reported experimental data. This complex model may lead to a better understanding of the function of TLR9 and its interaction with CpG ODN and will improve our understanding of TLR9-ligand interaction in general
Population Size, Genetic Diversity and Molecular Evidence of a Recent Population Bottleneck in Hynobius chinensis, an Endangered Salamander Species
Severe population declines can reduce species to small populations, offering permissive conditions for deleterious processes. For example, following such events, species can become prone to inbreeding and genetic drift which can lead to a loss of genetic diversity and evolutionary potentials. Hynobius chinensis is a poorly studied very rare and declining endangered amphibian species endemic to China in Changyang County. We investigated adult census population size by monitoring breeding populations from 2015 to 2018, developed microsatellite markers from the transcriptome and used them to investigate genetic diversity, and a population bottleneck in this species. We found H. chinensis in 4 different localities in a total area of 2.18 km2 and estimated the overall adult census population size at 386–404 individuals. The adult census size (mean ± SE) per breeding pond ranged from 44 ± 6 to 141 ± 8 individuals and appeared smaller than that reported in closely related species in undisturbed habitats. We developed and characterized 13 microsatellite markers in total. Analysis of data at 7 loci (N = 118) in Hardy-Weinberg equilibrium gathered from the largest population showed that genetic diversity level was low. The average number of alleles per locus was 2.14. The observed and expected heterozygosities averaged 0.38 and 0.40, respectively. The inbreeding coefficient was –0.06. All tests performed to investigate a population bottleneck, i.e. The Garza-Williamson test, Heterozygosity excess test, Mode shift test of allele frequency, and effective population size estimates detected a population bottleneck. The contemporary and the historical effective population sizes were estimated at 36 and 234 individuals, respectively. We argue that as bottleneck effects, the studied population may have become prone to genetic drift and inbreeding, losing microsatellite alleles and heterozygosity. Our results suggest that populations of H. chinensis may have been extirpated in the study area
Interleukin-10 Genotype Correlated to Deficiency Syndrome in Hepatitis B Cirrhosis
Traditional Chinese medicine (TCM) syndrome is an important basis for TCM diagnosis and treatment. As Child-Pugh classification as well as compensation and decompensation phase in liver cirrhosis, it is also an underlying clinical classification. In this paper, we investigated the correlation between single nucleotide polymorphisms (SNPs) of Interleukin-10 (IL-10) and TCM syndromes in patients with hepatitis B cirrhosis (HBC). Samples were obtained from 343 HBC patients in China. Three SNPs of IL-10 (−592A/C, −819C/T, and −1082A/G) were detected with polymerase chain-reaction-ligase detection reaction (PCR-LDR). The result showed the SNP-819C/T was significantly correlated with Deficiency syndrome (P = 0.031), but none of the 3 loci showed correlation either with Child-Pugh classification and phase in HBC patients. The logistic regression analysis showed that the Excess syndrome was associated with dizzy and spider nevus, and the Deficiency syndrome was associated with dry eyes, aversion to cold, IL-10-819C/T loci, and IL-10-1082A/G loci. The odds ratio (OR) value at IL-10-819C/T was 4.022. The research results suggested that IL-10-819C/T locus (TC plus CC genotype) is probably a risk factor in the occurrence of Deficiency syndrome in HBC patients
Taxonomy and Multi-Gene Phylogeny of Poroid Panellus (Mycenaceae, Agaricales) With the Description of Five New Species From China
Panellus is an Agaricales genus with both lamellate and poroid hymenophore. The poroid species are readily overlooked because of their tiny basidiocarps. The Chinese samples of poroid Panellus are studied, and five species, namely Panellus alpinus, Panellus crassiporus, Panellus longistipitatus, Panellus minutissimus, and Panellus palmicola are described as new species based on morphology and molecular phylogenetic analyses inferred from an nrITS dataset and a multi-gene dataset (nrITS + nrLSU + mtSSU + nrSSU + tef1). Panellus alpinus is characterized by its round to ellipsoid pores measuring 4–6 per mm and oblong ellipsoid basidiospores measuring 4.8–6 μm × 2.8–3.6 μm; P. crassiporus differs from other poroid species in the genus by the irregular pores with thick dissepiments and globose basidiospores measuring 8–9.8 μm × 6.9–8 μm; P. longistipitatus is distinguished by its long stipes, pyriform cheilocystidia, and broadly ellipsoid to subglobose basidiospores measuring 7–9.8 μm × 5–7 μm; P. minutissimus is characterized by its tiny and gelatinous basidiocarps, 5–20 pores per basidiocarp, and ellipsoid basidiospores measuring 6–8 μm × 3.2–4.2 μm; P. palmicola is characterized by its round pores measuring 2–4 per mm, the presence of acerose basidioles, and globose basidiospores measuring 7–9.5 μm × 6.2–8.2 μm. An identification key to 20 poroid species of Panellus is provided
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