708 research outputs found

    Ferromagnetism in polynuclear systems based on non- linear [(Mn2MnIII)-Mn-II] building blocks

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    The design of new polynuclear transition metal complexes showing large total spin values through parallel alignment of the spins is an important challenge due to the scarcity of bridging ligands that provide ferromagnetic coupling. Herein, we report two new complexes, a [(Mn4Mn2III)-Mn-II] system containing two non-linear [(Mn2MnIII)-Mn-II] units and a 1D chain system with [(Mn2MnIII)-Mn-II] units that are assembled through dicyanamide bridging ligands coordinated to one of the terminal Mn-II centers. In both cases, the main exchange interaction is between Mn-II center dot center dot center dot Mn-III, showing a relatively strong ferromagnetic coupling. Density functional theory calculations corroborate such ferromagnetic interactions and also provide one magnetostructural correlation, showing that larger Mn-II-O-Mn-III angles enhance the strength of the ferromagnetic coupling. Thus, the non-linear [(Mn2MnIII)-Mn-II] units present in these two complexes are specially suited because of their larger Mn-II-O-Mn-III angles compared to similar previously reported systems containing a linear [(Mn2MnIII)-Mn-II] unit

    Increased plasma apoM levels in the patients suffered from hepatocellular carcinoma and other chronic liver diseases

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    <p>Abstract</p> <p>Objective</p> <p>To determine plasma apolipoprotein M (apoM) levels and other lipid profiles in hepatocellular carcinoma (HCC) patients compared to other chronic liver diseases and normal subjects.</p> <p>Materials and methods</p> <p>36 HCC, 68 chronic hepatitis, 29 liver cirrhosis patients and 64 normal controls were subjected in the present study. Serum lipids, lipoproteins, apolipoprotein AI (apoAI) and apoB were determined by the conventional methods. Plasma apoM levels were semi-quantitatively determined by both dot-blotting and western blotting analysis.</p> <p>Results</p> <p>Serum levels of triglycerides (TG), HDL-cholesterol, apoAI and lipoprotein (a) (Lp(a)) were significantly lower in the HCC patients than in the normal subjects, whereas there were no obvious differences on serum total cholesterol, LDL-cholesterol and apoB between HCC patients and normal subjects. However, plasma apoM levels in HCC patients were significantly increased than those in the normal subjects, but lower than those in the chronic hepatitis and cirrhosis patients.</p> <p>Conclusion</p> <p>It is concluded that serum TG, apoAI, HDL-C and Lp(a) were significantly decreased in HCC patients than in controls, whereas plasma apoM levels were significantly increased in the HCC patients. Decreased serum TG, apoAI, HDL-C and Lp(a) may reflect the liver damage in HCC patients, whereas the clinical significance of increased plasma apoM levels in relation to HCC is not clear.</p

    Palmitic acid suppresses apolipoprotein M gene expression via the pathway of PPARβ/δ in HepG2 cells.

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    It has been demonstrated that apolipoprotein M (APOM) is a vasculoprotective constituent of high density lipoprotein (HDL), which could be related to the anti-atherosclerotic property of HDL. Investigation of regulation of APOM expression is of important for further exploring its pathophysiological function in vivo. Our previous studies indicated that expression of APOM could be regulated by platelet activating factor (PAF), transforming growth factors (TGF), insulin-like growth factor (IGF), leptin, hyperglycemia and etc., in vivo and/or in vitro. In the present study, we demonstrated that palmitic acid could significantly inhibit APOM gene expression in HepG2 cells. Further study indicated neither PI-3 kinase (PI3K) inhibitor LY294002 nor protein kinase C (PKC) inhibitor GFX could abolish palmitic acid induced down-regulation of APOM expression. In contrast, the peroxisome proliferator-activated receptor beta/delta (PPARβ/δ) antagonist GSK3787 could totally reverse the palmitic acid-induced down-regulation of APOM expression, which clearly demonstrates that down-regulation of APOM expression induced by palmitic acid is mediated via the PPARβ/δ pathway

    Rosiglitazone Enhances Apolipoprotein M (Apom) Expression in Rat's Liver.

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    Apolipoprotein M (APOM) has been suggested as a vasculoprotective constituent of high density lipoprotein (HDL), which plays a crucial role behind the mechanism of HDL-mediated anti-atherosclerosis. Previous studies demonstrated that insulin resistance could associate with decreased APOM expressions. In agreement with our previous reports, here, we further confirmed that the insulin sensitivity was also reduced in rats treated with high concentrations of glucose; such effect could be reversed by administration of rosiglitazone, a peroxisome proliferator-activated receptor-γ (PPARγ). The present study shows that Apom expression is significantly affected by either rosiglitazone or hyperglycemia alone without cross interaction with each other, which indicates that the pathway of Apom expression regulating by hyperglycemia might be differed from that by rosiglitazone. Further study indicated that hyperglycemia could significantly inhibit mRNA levels of Lxrb (P=0.0002), small heterodimer partner 1 (Shp1) (P<0.0001), liver receptor homologue-1 (Lrh1) (P=0.0012), ATP-binding cassette transporter 1 (Abca1) (P=0.0012) and Pparb/d (P=0.0043). Two-way ANOVA analysis demonstrated that the interactions between rosiglitazone and infusion of 25% glucose solution on Shp1 (P=0.0054) and Abca1 (4E, P=0.0004) mRNA expression was statistically significant. It is concluded that rosiglitazone could increase Apom expression, of which the detailed mechanism needs to be further investigated. The downregulation of Apom by hyperglycemia might be mainly through decreasing expression of Pparg and followed by inhibiting Lxrb in rats

    Impact of HIV-1 genetic diversity on disease progression: a prospective cohort study in Guangxi

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    The high proportion of AIDS cases and mortality rates in Guangxi underscores the urgency to investigate the influence of HIV-1 genetic diversity on disease progression in this region. Newly diagnosed HIV-1 patients were enrolled from January 2016 to December 2021, and the follow-up work and detection of CD4+T lymphocytes were carried out every six months until December 2022. Multivariate logistic regression was used to analyze the factors affecting pre-treatment CD4+T lymphocyte counts, while local weighted regression models (LOESS) and generalized estimating equation models (GEE) were conducted to assess factors influencing CD4+T Lymphocyte Recovery. Cox regression analysis was utilized to examine the impact of subtypes on survival risk. Additionally, HIV-1 env sequences were utilized for predicting CXCR4 and CCR5 receptors. The study encompassed 1867 individuals with pol sequences and 281 with env sequences. Our findings indicate that age over 30, divorced/widowed, peasant, heterosexual infection, CRF01_AE, long-term infection, and Pre-treatment Viral load &gt;10000 copies/ml were factors associated with higher risk for pre-treatment CD4+T lymphocyte decline. Specifically, male gender, age over 30, heterosexual infection (HETs), long-term infection, CRF01_AE, and Pre-treatment CD4 T cell counts below 350/µL were identified as risk factors impeding CD4+T lymphocyte recovery. Pre-treatment CD4+T lymphocyte counts and recovery in individuals infected with CRF01_AE were lower compared to CRF07_BC and CRF55_01B. Additionally, CRF01_AE and CRF08_BC subtypes exhibited higher mortality rates than CRF07_BC, CRF55_01B, and other subtypes. Notably, CRF01_AE demonstrated the highest percentage of CXCR4 affinity ratios. This research unveils the intricate influence of HIV-1 gene diversity on CD4+T lymphocyte dynamics and clinical outcomes. It highlights the multifaceted nature of HIV infection in Guangxi, providing novel insights into subtype-specific disease progression among HIV-infected individuals in this region

    Biogeographic Distribution Patterns of the Archaeal Communities Across the Black Soil Zone of Northeast China

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    Although archaea are ubiquitous in various environments, the knowledge gaps still exist regarding the biogeographical distribution of archaeal communities at regional scales in agricultural soils compared with bacteria and fungi. To provide a broader biogeographical context of archaeal diversity, this study quantified the abundance and community composition of archaea across the black soil zone in northeast China using real-time PCR and high-throughput sequencing (HTS) methods. Archaeal abundances across all soil samples ranged from 4.04 × 107 to 26.18 × 107 16S rRNA gene copies per gram of dry soil. Several soil factors were positively correlated with the abundances including soil pH, concentrations of total C, N, and P, and available K in soil, and soil water content. Approximately 94.2, 5.7, and 0.3% of archaeal sequences, and 31, 151, and 3 OTUs aligned within the phyla Thaumarchaeota, Euryarchaeota, and Crenarchaeota, respectively. Within the phylum of Thaumarchaeota, group 1.1b was a dominating genus accounting for an average of 87% archaeal sequences and phylogenetically classified as Nitrososphaera, a genus of ammonia oxidizing archaea. The response of dominating OTUs to environmental factors differed greatly, suggesting the physiological characteristics of different archaeal members is diversified in the black soils. Although the number of OTUs was not related with any particular soil parameters, the number of OTUs within Thaumarchaeota and Euryarchaeota was marginally related with soil pH. Archaeal community compositions differed between samples, and a Canonical correspondence analysis (CCA) analysis indicated that soil pH and the latitude of sampling locations were two dominating factors in shifting community structures. A variance partitioning analysis (VPA) analysis showed that the selected soil parameters (32%) were the largest drivers of community variation, in particular soil pH (21%), followed by geographic distances (19%). These findings suggest that archaeal communities have distinct biogeographic distribution pattern in the black soil zone and soil pH was the key edaphic factor in structuring the community compositions

    Enhanced identification and biological validation of differential gene expression via Illumina whole-genome expression arrays through the use of the model-based background correction methodology

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    Despite the tremendous growth of microarray usage in scientific studies, there is a lack of standards for background correction methodologies, especially in single-color microarray platforms. Traditional background subtraction methods often generate negative signals and thus cause large amounts of data loss. Hence, some researchers prefer to avoid background corrections, which typically result in the underestimation of differential expression. Here, by utilizing nonspecific negative control features integrated into Illumina whole genome expression arrays, we have developed a method of model-based background correction for BeadArrays (MBCB). We compared the MBCB with a method adapted from the Affymetrix robust multi-array analysis algorithm and with no background subtraction, using a mouse acute myeloid leukemia (AML) dataset. We demonstrated that differential expression ratios obtained by using the MBCB had the best correlation with quantitative RT–PCR. MBCB also achieved better sensitivity in detecting differentially expressed genes with biological significance. For example, we demonstrated that the differential regulation of Tnfr2, Ikk and NF-kappaB, the death receptor pathway, in the AML samples, could only be detected by using data after MBCB implementation. We conclude that MBCB is a robust background correction method that will lead to more precise determination of gene expression and better biological interpretation of Illumina BeadArray data

    Coprinus leucostictus rediscovered after a century, epitypified, and its generic position in Hausknechtia resolved by multigene phylogenetic analysis of Psathyrellaceae

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    About a century after the first finding in northern Vietnam (1908), Coprinus leucostictus is rediscovered on 12 localities in southern India and southern to southeastern China, growing in evergreen subtropical or tropical forests. It is morphologically a rather unique species with coprinoid basidiomata, strongly branched and diverticulate veil hyphae, and a hymeniderm pileipellis. The BLAST search of ITS and tef-1a sequences showed its close relationship to Hausknechtia floriformis, which is not clear based on morphological characters. Multigene phylogenetic analysis of a concatenated dataset of ITS, LSU, tef-1a, and -tubulin sequences, revealed C. leucostictus and H. floriformis as separate, but sister species. Molecular phylogenetic relationships within the family Psathyrellaceae (including 17 genera) are presented in the phylogram. The genera Hausknechtia and Candolleomyces formed two well-supported lineages and were recovered as a monophyletic group. A total of 27 sequences from the genus Hausknechtia were newly generated in this study. Coprinus leucostictus is combined as Hausknechtia leucosticta, its epitype is designated, and the hitherto monotypic genus Hausknechtia is emended. A detailed morphological description of H. leucosticta supplemented with colour photographs and line drawings is provided

    Check on the features of potted 20-inch PMTs with 1F3 electronics prototype at Pan-Asia

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    The Jiangmen underground neutrino observatory (JUNO) is a neutrino project with a 20-kton liquid scintillator detector located at 700-m underground. The large 20-inch PMTs are one of the crucial components of the JUNO experiment aiming to precision neutrino measurements with better than 3% energy resolution at 1 MeV. The excellent energy resolution and a large fiducial volume provide many exciting opportunities for addressing important topics in neutrino and astro-particle physics. With the container #D at JUNO Pan-Asia PMT testing and potting station, the features of waterproof potted 20-inch PMTs were measured with JUNO 1F3 electronics prototype in waveform and charge, which are valuable for better understanding on the performance of the waterproof potted PMTs and the JUNO 1F3 electronics. In this paper, basic features of JUNO 1F3 electronics prototype run at Pan-Asia will be introduced, followed by an analysis of the waterproof potted 20-inch PMTs and a comparison with the results from commercial electronics used by the container #A and #B
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