75 research outputs found

    Cyclic Delay-Doppler Shift: A Simple Transmit Diversity Technique for Delay-Doppler Waveforms in Doubly Selective Channels

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    Delay-Doppler waveform design has been considered as a promising solution to achieve reliable communication under high-mobility channels for the space-air-ground-integrated networks (SAGIN). In this paper, we introduce the cyclic delay-Doppler shift (CDDS) technique for delay-Doppler waveforms to extract transmit diversity in doubly selective channels. Two simple CDDS schemes, named time-domain CDDS (TD-CDDS) and modulation-domain CDDS (MD-CDDS), are proposed in the setting of multiple-input multiple-output (MIMO). We demonstrate the applications of CDDS on two representative delay-Doppler waveforms, namely orthogonal time frequency space (OTFS) and affine frequency division multiplexing (AFDM), by deriving their corresponding CDDS matrices. Furthermore, we prove theoretically and experimentally that CDDS can provide OTFS and AFDM with full transmit diversity gain on most occasions

    Root morphological, Cd accumulation and tolerance characteristics of 2 Dianthus caryophyllus cultivars under Cd stress

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    For studying the physiological response of two different Dianthus caryophyllus cultivars on Cd stress, pot experiment was carried out to measure proline and glutathione in leaves, five types of organic acids in root exudates (oxalic acid, malic acid, acetic acid, tartaric acid, citric acid), soluble sugars and free amino acids, root length, root surface area, root volume, root projected area and Cadmium content in soil, plant roots and aboveground. According to the effects of cadmium stress on the physiological and biochemical characteristics of two Dianthus caryophyllus, the results showed that: the growth of two cultivars are affected, “Master” and “Xiao Yan” are manifested as plant height, leaf, flower buds and biomass decreased, but the “Master” by the stronger inhibitory effect. The root length, total root surface area, total root projected area, and average root diameter of the “Master” increased under cadmium stress, but the root volume decreased. However, the root length, total root surface area, root volume, and root projected area of the “Xiao Yan” under cadmium stress decreased, while the average root diameter increased. The glutathione in the leaves of the two cultivars decreased, the proline content of the leaves of the “Xiao Yan” increased, while that of the “Master” decreased. In the root exudates, the free amino acid content of the two cultivars are reduced, and the secretion of organic acids is also inhibited (except for the citric acid secreted in the “Master”), while the soluble sugar content in the root exudates is expressed as “Xiao Yan” increased, and the “Master” decreased. According to the physiological response to the two cultivars under cadmium stress, the “Xiao Yan” is more suitable for soil restoration in the mining area of Lanping area

    Protection of p-coumaric acid against chronic stress-induced neurobehavioral deficits in mice via activating the PKA-CREB-BDNF pathway

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    There is a body of evidence to suggest that chronic stress modulates neurochemical homeostasis, alters neuronal structure, inhibits neurogenesis and contributes to development of mental disorders. Chronic stress-associated mental disorders present common symptoms of cognitive impairment and depression with complex disease mechanisms. P-coumaric acid (p-CA), a natural phenolic compound, is widely distributed in vegetables, cereals and fruits. P-CA exhibits a wide range of health-related effects, including anti-oxidative-stress, anti-mutagenesis, anti-inflammation and anti-cancer activities. The current study aims to evaluate the therapeutic potential of p-CA against stress-associated mental disorders. We assessed the effect of p-CA on cognitive deficits and depression-like behavior in mice exposed to chronic restraint stress (CRS); we used network pharmacology, biochemical and molecular biological approaches to elucidate the underlying molecular mechanisms. CRS exposure caused memory impairments and depression-like behavior in mice; p-CA administration attenuated these CRS-induced memory deficits and depression-like behavior. Network pharmacology analysis demonstrated that p-CA was possibly involved in multiple targets and a variety of signaling pathways. Among them, the protein kinase A (PKA) - cAMP-response element binding protein (CREB) - brain derived neurotrophic factor (BDNF) signaling pathway was predominant and further characterized. The levels of PKA, phosphorylated CREB (pCREB) and BDNF were significantly lowered in the hippocampus of CRS mice, suggesting disruption of the PKA-CREB-BDNF signaling pathway signaling pathway; p-CA treatment restored the signaling pathway. Furthermore, CRS upregulated expression of proinflammatory cytokines in hippocampus, while p-CA reversed the CRS-induced effects. Our findings suggest that p-CA will offer therapeutic benefit to patients with stress-associated mental disorders

    Chinese medicine, Qijudihuang pill, mediates cholesterol metabolism and regulates gut microbiota in high-fat diet-fed mice, implications for age related macular degeneration

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    Background: Traditional Chinese Medicines have been used for thousands of years but without any sound empirical basis. One such preparation is the Qijudihuang pill (QP), a mixture of eight herbs, that has been used in China for the treatment of various conditions including age-related macular degeneration (AMD), the most common cause of blindness in the aged population. In order to explain the mechanism behind the effect of QP, we used an AMD model of high-fat diet (HFD) fed mice to investigate cholesterol homeostasis, oxidative stress, inflammation and gut microbiota.Methods: Mice were randomly divided into three groups, one group was fed withcontrol diet (CD), the other two groups were fed with high-fat-diet (HFD). OneHFD group was treated with QP, both CD and the other HFD groups were treatedwith vehicles. Tissue samples were collected after the treatment. Cholesterollevels in retina, retinal pigment epithelium (RPE), liver and serum weredetermined using a commercial kit. The expression of enzymes involved incholesterol metabolism, inflammation and oxidative stress was measured withqRT-PCR. Gut microbiota was analyzed using 16S rRNA sequencing.Results: In the majority of the lipid determinations, analytes were elevated by HFD but thiswas reversed by QP. Cholesterol metabolism including the enzymes of bile acid (BA) formationwas suppressed by HFD but again thiswas reversed by QP. BAs play amajor role in signaling between host andmicrobiome and this is disrupted by HFD resulting in major changes in the composition of colonic bacterial communities. Associated with these changes are predictions of the metabolic pathway complexity and abundance of individual pathways. These concerned substrate breakdowns, energy production and the biosynthesis of proinflammatory factors but were changed back to control characteristics by QP.Conclusion: We propose that the ability of QP to reverse these HFD-inducedeffects is related to mechanisms acting to lower cholesterol level, oxidative stress and inflammation, and to modulate gut microbiota

    HPtaa database-potential target genes for clinical diagnosis and immunotherapy of human carcinoma

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    Tumor-associated antigens (TAAs) have been the most actively employed targets in the clinical diagnosis and treatment of human carcinoma, such as PSA in the diagnosis of prostate cancer and NY-ESO-1 in the immunotherapy of melanoma and other cancers. However, identification of TAAs has often been hampered by the complicated and laborsome laboratory procedures. In order to accelerate the process of tumor antigen discovery, and thereby improve diagnosis and treatment of human carcinoma, we have made an effort to establish a publicly available Human Potential Tumor Associated Antigen database (HPtaa) with potential TAAs identified by in silico computing (). Tumor specificity was chosen as the core of tumor antigen evaluation, together with other relevant clues. Various platforms of gene expression, including microarray, expressed sequence tag and SAGE data, were processed and integrated by several penalty algorithms. A total of 3518 potential TAAs have been included in the database, which is freely available to academic users. As far as we know, this database is the first one addressing human potential TAAs, and the first one integrating various kinds of expression platforms for one purpose

    Integrated metabolomics and metagenomics analysis of plasma and urine identified microbial metabolites associated with coronary heart disease

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    Coronary heart disease (CHD) is top risk factor for health in modern society, causing high mortality rate each year. However, there is no reliable way for early diagnosis and prevention of CHD so far. So study the mechanism of CHD and development of novel biomarkers is urgently needed. In this study, metabolomics and metagenomics technology are applied to discover new biomarkers from plasma and urine of 59 CHD patients and 43 healthy controls and trace their origin. We identify GlcNAc-6-P which has good diagnostic capability and can be used as potential biomarkers for CHD, together with mannitol and 15 plasma cholines. These identified metabolites show significant correlations with clinical biochemical indexes. Meanwhile, GlcNAc-6-P and mannitol are potential metabolites originated from intestinal microbiota. Association analysis on species and function levels between intestinal microbes and metabolites suggest a close correlation between Clostridium sp. HGF2 and GlcNAc-6-P, Clostridium sp. HGF2, Streptococcus sp. M143, Streptococcus sp. M334 and mannitol. These suggest the metabolic abnormality is significant and gut microbiota dysbiosis happens in CHD patients

    A comparative analysis of morphology, microstructure, and volatile metabolomics of leaves at varied developmental stages in Ainaxiang (Blumea balsamifera (Linn.) DC.)

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    IntroductionAinaxiang (Blumea balsamifera (Linn.) DC.) is cultivated for the extraction of (-)-borneol and other pharmaceutical raw materials due to its abundant volatile oil. However, there is limited knowledge regarding the structural basis and composition of volatile oil accumulation in fresh B. balsamifera leaves.MethodsTo address this problem, we compare the fresh leaves’ morphology, microstructure, and volatile metabonomic at different development stages, orderly defined from the recently unfolded young stage (S1) to the senescent stage (S4).Results and discussionDistinct differences were observed in the macro-appearance and microstructure at each stage, particularly in the B. balsamifera glandular trichomes (BbGTs) distribution. This specialized structure may be responsible for the accumulation of volatile matter. 213 metabolites were identified through metabolomic analysis, which exhibited spatiotemporal accumulation patterns among different stages. Notably, (-)-borneol was enriched at S1, while 10 key odor metabolites associated with the characteristic balsamic, borneol, fresh, and camphor aromas of B. balsamifera were enriched in S1 and S2. Ultra-microstructural examination revealed the involvement of chloroplasts, mitochondria, endoplasmic reticulum, and vacuoles in the synthesizing, transporting, and storing essential oils. These findings confirm that BbGTs serve as the secretory structures in B. balsamifera, with the population and morphology of BbGTs potentially serving as biomarkers for (-)-borneol accumulation. Overall, young B. balsamifera leaves with dense BbGTs represent a rich (-)-borneol source, while mesophyll cells contribute to volatile oil accumulation. These findings reveal the essential oil accumulation characteristics in B. balsamifera, providing a foundation for further understanding

    Safety evaluation of LD27-2 WHPB platform based on rod pumping

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    Abstract The development of heavy oil with high efficiency is a worldwide difficulty for offshore oil field. The technology of rod pumping provides a possible effective way for offshore heavy oil thermal recovery, but the safety of working platform is the prerequisite for the implementation of this new technology. In this paper, the mechanical model of LD27-2 WHPB platform is established, and the safety performance of the platform under hydraulic pumping unit (HPU) load is evaluated. The distribution of the combined HPU load accords with the classical probability model. When the HPUs are all synchronous, the combined load reaches its maximum. The finite element-based platform safety analysis under the extreme condition is carried out. Under the combined action of wave current, wind load and the extreme HPU load, the maximum stress of the jacket is 83.2 MPa, and the safety coefficient is 4.33, indicating the overall strength of LD27-2 WHPB platform meets the safety requirement

    Pedestrian crash risk assessment and intervention

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    This article is aimed at identifying the main risk behaviors of pedestrians, sorting them on the basis of risk levels, and, moreover, performing risk assessment and intervention for the pedestrian. In order to achieve this goal, this article analyzes a large amount of traffic accident data in Beijing and finds that the movable sight obstacle is an important cause for traffic accident between pedestrians and motor vehicle (hereinafter referred a vehicle–pedestrian accident). Some tables and figures display when and where the movable sight obstacle usually occurs and also shows their logical relationship with other causes. Based on the results of investigation and analysis, the vehicle–pedestrian mechanism diagram was established using the method of fault tree analysis. The diagram shows some key factors and their effect level leading to the accident. The key importance coefficient model was adopted to estimate the function of individual risk behavior quantitatively during the processing of accident. In order to take advantage of the key importance coefficient model, the following research was conducted: first, we analyzed traffic accident data from 2005 to 2014 to find common pedestrians risk behaviors. Second, since traffic accidents and movable sight obstacle are closely related to motor vehicle violations, we collected and analyzed the data of traffic enforcement from 2007 to 2014. Finally, taking into account the individual preferences of policemen, we interviewed 200 police officers and others to calibrate our estimates. Through these efforts, we sorted the pedestrians’ risk behaviors in table. Unlike past research, the object of this study is pedestrian risk behaviors and faults. Furthermore, we also gained understanding to the mechanism of vehicle–pedestrian accident, which was already applied to assessment and intervention for pedestrians in some primary schools in Beijing
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