20 research outputs found

    Geology, U-Pb geochronology and stable isotope geochemistry of the Heihaibei gold deposit in the southern part of the Eastern Kunlun Orogenic Belt, China : A granitic intrusion-related gold deposit?

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    The Heihaibei gold deposit is a newly discovered gold deposit in the southern part of the Eastern Kunlun Orogenic Belt. Its most distinctive features are that the gold mineralization is hosted in monzogranite, and that the presence of pre-ore (possibly syn-ore) monzogranite and post-ore gabbro allows to constrain the minerali-zation's formation age. Zircons from the monzogranites yield U-Pb ages of 454 +/- 3 Ma, while zircons separated from the gabbro dikes cutting the monzogranites and gold mineralized body yield U-Pb ages of 439 +/- 3 Ma, which is interpreted to be the minimum age of the Au mineralizing event. Combined with the regional geological background, we proposed that the Heihaibei Au mineralization occurred during the subduction stage of the Early Paleozoic Proto-Tethys ocean. The ore assemblage is dominated by pyrite, arsenopyrite and native gold. The hydrothermal alteration that has led to the peculiar enrichment of Au is not systematically distributed and displays no clear concentric zoning pattern. The main mineralization formed during three stages: the K-feldspar-quartz-pyrite (Py1)-arsenopyrite-sericite-epidote stage (I), the quartz-pyrite (Py2)-native gold-chlorite stage (II), and the quartz-carbonate stage (III). The main gold mineralization occurred during stage II. Fluid inclusion homogenization temperature and salinities decrease from stage I (Th., 268-412 C; W., 6.87-16.63 wt% NaCl equiv.) to stage II (Th., 183-288 C; W., 3.69-14.84 wt% NaCl equiv.). The 818O and 8D values (818OH2O = 4.9 to 9.7%o; 8DV-SMOW =-84.1%o to -81.1%o) of quartz samples from stage I and stage II are comparable to a magmatic-hydrothermal ore-forming fluid that possibly underwent fluid-rock interaction with the Nachitai Group metamorphic rocks during the early ore-forming stage. The relatively uniform 834S values (834SV-CDT = 7.7 to 8.5%o) are slightly elevated compared to magmatic 834S values, but could be derived from a magma if a significant crustal melt component is present. Moreover, the 834S values are within the S isotopic composition range of a granitic reservoir, suggesting that they are probably inherited from the Heihaibei monzogranites. The Pb and Hf isotope compositions imply a close genetic association between the gold mineralization and granitic magmatism, which are both the products of the mixing of crustal and mantle sources. The trace element compositions of pyrite provide additional evidence that the gold mineralization in the Heihaibei deposit was related to the magmatism. Compared with the typical characteristics of orogenic gold and intrusion-related gold systems (IRGS) deposits, the Heihaibei gold deposit may instead be classified as a granitic intrusion-related gold deposit.Peer reviewe

    Animal venoms: a novel source of anti-Toxoplasma gondii drug candidates

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    Toxoplasma gondii (T. gondii) is a nucleated intracellular parasitic protozoan with a broad host selectivity. It causes toxoplasmosis in immunocompromised or immunodeficient patients. The currently available treatments for toxoplasmosis have significant side effects as well as certain limitations, and the development of vaccines remains to be explored. Animal venoms are considered to be an important source of novel antimicrobial agents. Some peptides from animal venoms have amphipathic alpha-helix structures. They inhibit the growth of pathogens by targeting membranes to produce lethal pores and cause membrane rupture. Venom molecules generally possess immunomodulatory properties and play key roles in the suppression of pathogenic organisms. Here, we summarized literatures of the last 15 years on the interaction of animal venom peptides with T. gondii and attempt to explore the mechanisms of their interaction with parasites that involve membrane and organelle damage, immune response regulation and ion homeostasis. Finally, we analyzed some limitations of venom peptides for drug therapy and some insights into their development in future studies. It is hoped that more research will be stimulated to turn attention to the medical value of animal venoms in toxoplasmosis

    Development of Inflammatory Immune Response-Related Drugs Based on G Protein-Coupled Receptor Kinase 2

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    G protein-coupled receptor kinase 2 (GRK2), as a vital Ser/Thr kinase, is an important regulatory protein in the inflammatory immune response (IIR) by maintaining the balance between the function of inflammatory immune cells and non-conventional inflammatory immune cells and regulating inflammatory immune cell infiltration, inflammatory cytokine secretion, and the signaling associated with endothelial function. However, the imbalance of GRK2 expression and activity plays an important role in the development of IIR-related diseases, such as hypertension, heart failure, Alzheimer’s disease, type 2 diabetes mellitus, insulin resistance, rheumatoid arthritis, thyroid cancer, multiple sclerosis, and liver cancer. Small molecule GRK2 inhibitors, including balanol, Takeda inhibitors, paroxetine and derivatives, M119 and gallein, peptides, RNA aptamers, Raf kinase inhibitory protein, and microRNAs, that can directly inhibit GRK2 kinase activity have been identified by different strategies. This review discusses recent progress in one of the hallmark molecular abnormalities of GRK2 in IIR-related diseases and explores the soft regulation of IIR by innovative drugs reducing the excessive activity of GRK2 to basal levels, without damaging normal physiological function, to ameliorate inflammatory disorders

    Was the extended rainy winter of 2018/2019 over the Middle and Lower reaches of the Yangtze River driven by anthropogenic forcing?

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    Anthropogenic forcing reduced the probability of rainfall amount in the extended rainy winter of 2018/19 over the middle and lower reaches of the Yangtze River, China, by ~19%, but exerted no influence on the excessive rainy days, based on HadGEM3-GA6-N216 ensembles. Instead the natural variability played a large and important role in this event

    Mineralogical study on the magmatic rock in Cishan gold deposit, Tongling, China

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    1959-1967Present study consists the major and trace elements in minerals of clinopyroxene and zircon in the Baimangshan pluton using electron probe and in-situ LA-ICP-MS. The results reflect that the Baimangshan pluton is a transitional rock type from subalkaline series to alkaline series and may have developed at a transition setting, from active continental margin to intraplate tectonics. Parent magma is the underplating mantle-derived basaltic magma having similar composition to ocean island basalt(OIB). And the zircons were crystallized from the lower crust in which the basaltic magmas were less differentiated. Baimangshan pluton is an oxidation pluton. It is high in alkali, which is favorable for forming oxidation type skarn gold deposits. Magma may be the main source of the mineral matters

    Focused low-intensity pulsed ultrasound alleviates osteoarthritis via restoring impaired FUNDC1-mediated mitophagy

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    Summary: Mitophagy is critical for maintaining proper cellular functions, and it contributes to the onset and progression of osteoarthritis (OA). A recent study showed that focused low-intensity pulsed ultrasound (FLIPUS) could activate mitophagy, but the molecular mechanism remains unclear. This study aimed to elucidate the chondroprotective effects of FLIPUS in OA and the regulatory effects on FUN14-domain containing 1 (FUNDC1-mediated mitophagy. In vitro, FLIPUS improved inflammatory response, anabolism, and catabolism in interleukin (IL)-1β-induced OA chondrocytes. The chondroprotective effects of FLIPUS were attributed to promoting the expression of phosphoglycerate mutase 5 (PGAM5) and the dephosphorylation of FUNDC1 at serine 13 (Ser13), as well as promoting the mitophagy process. In vivo, FLIPUS reduced the cartilage degeneration and apoptosis and reversed the change of anabolic- and catabolic-related proteins in destabilized medial meniscus (DMM)-induced mouse model. Thus, the study indicates that FLIPUS exhibits a chondroprotective effect via activating impaired FUNDC1-mediated mitophagy

    Inter-Level Feature Balanced Fusion Network for Street Scene Segmentation

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    Semantic segmentation, as a pixel-level recognition task, has been widely used in a variety of practical scenes. Most of the existing methods try to improve the performance of the network by fusing the information of high and low layers. This kind of simple concatenation or element-wise addition will lead to the problem of unbalanced fusion and low utilization of inter-level features. To solve this problem, we propose the Inter-Level Feature Balanced Fusion Network (IFBFNet) to guide the inter-level feature fusion towards a more balanced and effective direction. Our overall network architecture is based on the encoder–decoder architecture. In the encoder, we use a relatively deep convolution network to extract rich semantic information. In the decoder, skip-connections are added to connect and fuse low-level spatial features to restore a clearer boundary expression gradually. We add an inter-level feature balanced fusion module to each skip connection. Additionally, to better capture the boundary information, we added a shallower spatial information stream to supplement more spatial information details. Experiments have proved the effectiveness of our module. Our IFBFNet achieved a competitive performance on the Cityscapes dataset with only finely annotated data used for training and has been greatly improved on the baseline network

    Petrogenesis and Tectonic Implications of the Triassic Granitoids in the Ela Mountain Area of the East Kunlun Orogenic Belt

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    The East Kunlun Orogenic Belt is located in the western part of the Central Orogenic Belt of China, with a large number of Triassic igneous rocks parallel to the Paleo-Tethys ophiolite belt, which provides a large amount of geological information for the tectonic evolution of the Paleo-Tethys Ocean. The granitoids studied in this paper are located in the Ela Mountain area in the eastern part of the East Kunlun Orogenic Belt. Zircon U-Pb dating results show that these different types of granitoids were crystallized in the Triassic. The 247.5 Ma porphyritic granites from Zairiri (ZRR) displayed calc-alkaline I-type granite affinities, with the zircon εHf(t) values being mainly positive (−0.5 to + 3.8, TDM2 of 1309–1031 Ma), indicating that they are derived from the partial melting of the juvenile crust and mixed with ancient crustal components. The 236.8 Ma Henqionggou (HQG) granodiorites and 237.5 Ma Daheba (DHB) granodiorites are high-K calc-alkaline I-type granite, and both have mafic microgranular enclaves (MMEs), showing higher and more varied Mg# (39.73–62.73), combined with their negative Hf isotopes (εHf(t) = −2.6 to −1.6, TDM2 = 1430–1369 Ma), suggesting that their primary magmas were the products of partial melting of the Mesoproterozoic lower crust that mixed with mantle-derived rocks. The 236.4 Ma DHB porphyritic diorites showed characteristics of high-K calc-alkaline I-type granitoids, with moderate SiO2 contents, medium Mg# values (40.41–40.65), with the Hf isotopes (εHf(t) = −2.9 to −0.5; TDM2 = 1451–1298 Ma) indistinguishably relative to contemporaneous host granodiorites and MMEs. The petrographic and geochemical characteristics indicate that the porphyritic diorites are the product of well-mixed magma derived from the Mesoproterozoic lower crust and lithospheric mantle. Based on the results of this paper and previous data, the chronology framework of Late Permian–Triassic magmatic rocks in the eastern part of the East Kunlun Orogenic Belt was constructed, and the magmatic activities in this area were divided into three peak periods, with each peak representing an extensional event in a particular tectonic setting, for example, P1 (slab roll-back in subduction period; 254–246 Ma), P2 (slab break-off in transition period of subduction and collision; 244–232 Ma), P3 (delamination after collision; 230–218 Ma)

    Anti-<i>Toxoplasma gondii</i> Effects of Lipopeptide Derivatives of Lycosin-I

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    Toxoplasmosis, caused by Toxoplasma gondii (T. gondii), is a serious zoonotic parasitic disease. We previously found that Lycosin-I exhibited anti-T. gondii activity, but its serum stability was not good enough. In this study, we aimed to improve the stability and activity of Lycosin-I through fatty acid chain modification, so as to find a better anti-T. gondii drug candidate. The α/ε-amino residues of different lysine residues of Lycosin-I were covalently coupled with lauric acid to obtain eight lipopeptides, namely L-C12, L-C12-1, L-C12-2, L-C12-3, L-C12-4, L-C12-5, L-C12-6, and L-C12-7. Among these eight lipopeptides, L-C12 showed the best activity against T. gondii in vitro in a trypan blue assay. We then conjugated a shorter length fatty chain, aminocaproic acid, at the same modification site of L-C12, namely L-an. The anti-T. gondii effects of Lycosin-I, L-C12 and L-an were evaluated via an invasion assay, proliferation assay and plaque assay in vitro. A mouse model acutely infected with T. gondii tachyzoites was established to evaluate their efficacy in vivo. The serum stability of L-C12 and L-an was improved, and they showed comparable or even better activity than Lycosin-I did in inhibiting the invasion and proliferation of tachyzoites. L-an effectively prolonged the survival time of mice acutely infected with T. gondii. These results suggest that appropriate fatty acid chain modification can improve serum stability and enhance anti-T. gondii effect of Lycosin-I. The lipopeptide derivatives of Lycosin-I have potential as a novel anti-T. gondii drug candidate
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