Off-grid direction-of-arrival estimation for wideband noncircular sources

Xiaoyu Zhang1,Haihong Tao,Ziye Fang,Jian Xie 한국전자통신연구원 2023 ETRI Journal Vol.45 No.3

Researchers have recently shown an increased interest in estimating the direction-of-arrival (DOA) of wideband noncircular sources, but existing studies have been restricted to subspace-based methods. An off-grid sparse recovery-based algorithm is proposed in this paper to improve the accuracy of existing algorithms in low signal-to-noise ratio situations. The covariance and pseudo covariance matrices can be jointly represented subject to block sparsity constraints by taking advantage of the joint sparsity between signal components and bias. Furthermore, the estimation problem is transformed into a single measurement vector problem utilizing the focused operation, resulting in a significant reduction in computational complexity. The proposed algorithm's error threshold and the Cramer–Rao bound for wideband noncircular DOA estimation are deduced in detail. The proposed algorithm's effectiveness and feasibility are demonstrated by simulation results.

Effect of Paecilomyces cateniannulatus on the adsorption of nickel onto graphene oxide

Xiaoyu Li,Fengbo Li,Lejin Fang 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.12

Graphene oxide (GO) was synthesized by chemical oxidation method and used to remove nickel (Ni(II)) from aqueous solutions in the presence of Paecilomyces cateniannulatus (P. cateniannulatus). Based on characteristic results, it was demonstrated that P. cateniannulatus was easily combined with carboxyl groups of GO by covalent bond. The adsorption results showed that P. cateniannulatus facilitated the adsorption of Ni(II) on GO over a wide range of pH. The maximum adsorption capacities of GO+P. cateniannulatus and GO calculated from Langmuir model at pH 4.0 and T=303 K were 104.2 and 81.3mg·g−1, respectively. According to the analysis of thermodynamic parameters, the adsorption of Ni(II) on GO+P. cateniannulatus was endothermic and spontaneous. The highlight of this study quantitatively assessed the effect of bacteria on the fate and transports of heavy metals in near-surface geologic systems.

Comparative transcriptome analysis to identify genes involved in terpenoid biosynthesis in Agriophyllum squarrosum, a folk medicinal herb native to Asian temperature deserts

Yin Xiaoyue,Yan-Xia Liu,Qian Chaoju,Zhou Shanshan,Fang Tingzhou,Fan Xingke,Gao yuan,Chang Yuxiao,Yang Jian,Ma Xiao-Fei 한국식물생명공학회 2021 Plant biotechnology reports Vol.15 No.3

Agriophyllum squarrosum is a folk Mongolian medicine with pleiotropic pharmacological and ecological economic importance endemic to Asian temperature deserts. Terpenoids play critical roles in biotic and abiotic stresses due to their antioxidative activities. Based on non-targeted metabolomic analysis, we detected eight terpenoids enriched in the above-ground tissues of A. squarrosum, however, the molecular mechanism underlying terpenoids biosynthesis in this desert medicinal plant is rarely understood. Here, a comparative transcriptome analysis of diferent tissues in A. squarrosum was conducted to identify 84 unigenes encoding key enzymes in the upstream backbone biosynthesis and 53 unigenes encoding the downstream enzymes for terpenoid diversifcation. Most of the upstream genes exhibited signifcant high expression levels in leaf, and some of which were validated by qRT-PCR. Phylogenetic analysis showed that two downstream gene families OSCs (oxidosqualene cyclases) and TPSs (mainly in terpene synthases -g subfamily) had undergone notable gene expansions in A. squarrosum comparing with the other Amaranthaceae plant species and Arabidopsis. Nevertheless, most members from these two gene families showed the tissue-specifc expression in A. squarrosum, which supported the diversifcation and tissue-specifc enrichment of terpenoids across above-ground tissues. Considering to the habitat characteristics of A. squarrosum, we proposed that the enrichment of terpenoids and the functional diversifcation of terpenoids biosynthesis enzymes were more or less involved into its adaptation to stressful environments of deserts. These results expand the available genetic information underlying terpenoid biosynthesis in A. squarrosum, and contribute to deeper researches on pharmaceutical and eco-agricultural applications in this desert medicinal plant.

Melatonin stimulates aromatase expression and estradiol production in human granulosa-lutein cells: relevance for the high serum estradiol levels in ovarian hyperstimulation syndrome

Jung-Chien Cheng,Lanlan Fang,Yiran Li,Sijia Wang,Yuxi Li,Yang Yan,Qiongqiong Jia,Ze Wu,Zhen Wang,Xiaoyu Han,Ying-Pu Sun 생화학분자생물학회 2020 Experimental and molecular medicine Vol.52 No.-

Ovarian hyperstimulation syndrome (OHSS) is one of the most life-threatening and potentially fatal complications associated with controlled ovarian hyperstimulation (COH) during in vitro fertilization (IVF) treatment. Although the pathogenesis of OHSS remains unclear, elevated serum estradiol (E2) levels before human chorionic gonadotropin (hCG) administration are associated with the risk of OHSS. The pineal hormone melatonin and its receptors are expressed in human granulosa cells and have been shown to stimulate E2 production. However, the effect of melatonin on the expression of aromatase, an enzyme responsible for a key step in the biosynthesis of E2, in human granulosa cells remains to be determined. Here, we demonstrate that melatonin upregulates aromatase expression in primary cultured human granulosa-lutein (hGL) cells through the melatonin receptor-mediated PKA-CREB pathway. Using a mouse model of OHSS, we demonstrate that administration of the melatonin receptor inhibitor luzindole inhibits the development of OHSS. In addition, the expression of ovarian aromatase and serum E2 levels are upregulated in OHSS mice compared to control mice, but this upregulation is attenuated by inhibition of the function of melatonin. Moreover, clinical results reveal that aromatase expression levels are upregulated in hGL cells from OHSS patients. Melatonin and E2 levels in the follicular fluid are significantly higher in OHSS patients than in non-OHSS patients. Furthermore, melatonin levels are positively correlated with E2 levels in follicular fluid. This study helps to elucidate the mechanisms mediating the expression of aromatase in hGL cells and provides a potential mechanism explaining the high E2 levels in patients with OHSS.

Discovery of Chitin Deacetylase Inhibitors through Structure-Based Virtual Screening and Biological Assays

( Yaodong Liu ),( Sibtain Ahmed ),( Yaowei Fang ),( Meng Chen ),( Jia An ),( Guang Yang ),( Xiaoyue Hou ),( Jing Lu ),( Qinwen Ye ),( Rongjun Zhu ),( Qitong Liu ),( Shu Liu ) 한국미생물생명공학회 2022 Journal of microbiology and biotechnology Vol.32 No.4

Chitin deacetylase (CDA) inhibitors were developed as novel antifungal agents because CDA participates in critical fungal physiological and metabolic processes and increases virulence in soil-borne fungal pathogens. However, few CDA inhibitors have been reported. In this study, 150 candidate CDA inhibitors were selected from the commercial Chemdiv compound library through structure-based virtual screening. The top-ranked 25 compounds were further evaluated for biological activity. The compound J075-4187 had an IC50 of 4.24 ± 0.16 μM for AnCDA. Molecular docking calculations predicted that compound J075-4187 binds to the amino acid residues, including active sites (H101, D48). Furthermore, compound J075-4187 inhibited food spoilage fungi and plant pathogenic fungi, with minimum inhibitory concentration (MIC) at 260 μg/ml and minimum fungicidal concentration (MFC) at 520 μg/ml. Therefore, compound J075-4187 is a good candidate for use in developing antifungal agents for fungi control.

Estrogen Receptor-α Exacerbates EGF-Inducing Airway Remodeling and Mucus Production in Bronchial Epithelium of Asthmatics

Qin Lu,Yue Junqing,Guo Mingzhou,Zhang Cong,Fang Xiaoyu,Zhang Shengding,Bai Wenxue,Liu Xiansheng,Xie Min 대한천식알레르기학회 2023 Allergy, Asthma & Immunology Research Vol.15 No.5

Purpose: Although estrogen receptors (ERs) signal pathways are involved in the pathogenesis and development of asthma, their expressions and effects remain controversial. This study aimed to investigate the expressions of ERα and ERβ as well as their mechanisms in airway remodeling and mucus production in asthma. Methods: The expressions of ERα and ERβ in the airway epithelial cells of bronchial biopsies and induced sputum cells were examined by immunohistochemistry. The associations of ERs expressions with airway inflammation and remodeling were evaluated in asthmatic patients. In vitro, the regulations of ERs expressions in human bronchial epithelial cell lines were examined using western blot analysis. The epidermal growth factor (EGF)-mediated ligand-independent activation of ERα and its effect on epithelial-mesenchymal transitions (EMTs) were investigated in asthmatic epithelial cells by western blot, immunofluorescent staining, and quantitative real-time polymerase chain reaction. Results: ERα and ERβ were expressed on both bronchial epithelial cells and induced sputum cells, and the expressions showed no sex difference. Compared to controls, male asthmatic patients had higher levels of ERα on the bronchial epithelium, and there were cell-specific expressions of ERα and ERβ in induced sputum. The expression of ERα in the airway epithelium was inversely correlated to forced expiratory volume in 1 second (FEV1) % and FEV1/forced vital capacity. Severe asthmatic patients had significantly greater levels of ERα in the airway epithelium than mild-moderate patients. ERα level was positively correlated with the thickness of the subepithelial basement membrane and airway epithelium. In vitro, co-stimulation of interleukin (IL)-4 and EGF increased the expression of ERα and promoted its nuclear translocation. EGF activated the phosphorylation of ERα via extracellular signal-regulated kinase and c-Jun N-terminal kinase pathways. ERα knockdown alleviated EGF-mediated EMTs and mucus production in airway epithelial cells of asthma. Conclusions: ERα contributes to asthmatic airway remodeling and mucus production through the EGF-mediated ligand-independent pathway.

Left Ventricular Remodeling in Patients with Primary Aldosteronism: A Prospective Cardiac Magnetic Resonance Imaging Study

Wu Tao,Ren Yan,Wang Wei,Cheng Wei,Zhou Fangli,He Shuai,Liu Xiumin,Li Lei,Tang Lu,Deng Qiao,Zhou Xiaoyue,Chen Yucheng,Sun Jiayu 대한영상의학회 2021 Korean Journal of Radiology Vol.22 No.10

Objective: This study used cardiac magnetic resonance imaging (MRI) to compare the characteristics of left ventricular remodeling in patients with primary aldosteronism (PA) with those of patients with essential hypertension (EH) and healthy controls (HCs). Materials and Methods: This prospective study enrolled 35 patients with PA, in addition to 35 age- and sex-matched patients with EH, and 35 age- and sex-matched HCs, all of whom underwent comprehensive clinical and cardiac MRI examinations. The analysis of variance was used to detect the differences in the characteristics of left ventricular remodeling among the three groups. Univariable and multivariable linear regression analyses were used to determine the relationships between left ventricular remodeling and the physiological variables. Results: The left ventricular end-diastolic volume index (EDVi) (mean ± standard deviation [SD]: 85.1 ± 13.0 mL/m2 for PA, 75.9 ± 14.3 mL/m2 for EH, and 77.3 ± 12.8 mL/m2 for HC; p = 0.010), left ventricular end-systolic volume index (ESVi) (mean ± SD: 35.2 ± 9.8 mL/m2 for PA, 30.7 ± 8.1 mL/m2 for EH, and 29.5 ± 7.0 mL/m2 for HC; p = 0.013), left ventricular mass index (mean ± SD: 65.8 ± 16.5 g/m2 for PA, 56.9 ± 12.1 g/m2 for EH, and 44.1 ± 8.9 g/m2 for HC; p < 0.001), and native T1 (mean ± SD: 1224 ± 39 ms for PA, 1201 ± 47 ms for EH, and 1200 ± 44 ms for HC; p = 0.041) values were higher in the PA group compared to the EH and HC groups. Multivariable linear regression demonstrated that log (plasma aldosteroneto- renin ratio) was independently correlated with EDVi and ESVi. Plasma aldosterone was independently correlated with native T1. Conclusion: Patients with PA showed a greater degree of ventricular hypertrophy and enlargement, as well as myocardial fibrosis, compared to those with EH. Cardiac MRI T1 mapping can detect left ventricular myocardial fibrosis in patients with PA.