Leaching and freeze-thaw events contribute to litter decomposition - a review

Litter decomposition is vital for carbon and nutrient turnover in terrestrial ecosystems, and this process has now been thoroughly demonstrated to be regulated by various mechanisms. The total environment has been continuously changing in recent decades, especially in high-latitude regions; these alterations, however, profoundly contribute to the decomposition process, but a comprehensive recognition has not available. Here we reviewed the empirical observations and current knowledge regarding how hydrological leaching and freeze-thaw events modulate early decomposition of plant litter. Leaching contributes a considerable percentage of mass loss and carbon and nutrient release in early stage of decomposition, but the magnitudes are different between species levels depending on the chemical traits. Frequent freezing and thawing events could positively influence decomposition rate in cold biomes but also hamper soil decomposer and there is no general and predictable pattern has been emerged. Further experiments should be manipulated to estimate how the altered freezing and thawing effect on carbon and nutrient release from plant litter to better understanding the changing environment on litter decomposition

NF-κB mediates the transcription of mouse calsarcin-1 gene, but not calsarcin-2, in C2C12 cells

BACKGROUND: The calsarcins comprise a novel family of muscle-specific calcineurin-interaction proteins that play an important role in modulating both the function and substrate specificity of calcineurin in muscle cells. The expression of calsarcin-1 (CS-1) is restricted to slow-twitch skeletal muscle fibres, whereas that of both calsarcin-2 (CS-2) and calsarcin-3 (CS-3) is enriched in fast-twitch fibres. However, the transcriptional control of this selective expression has not been previously elucidated. RESULTS: Our real-time RT-PCR analyses suggest that the expression of CS-1 and CS-2 is increased during the myogenic differentiation of mouse C2C12 cells. Promoter deletion analysis further suggests that an NF-κB binding site within the CS-1 promoter is responsible for the up-regulation of CS-1 transcription, but no similar mechanism was evident for CS-2. These findings are further supported by the results of EMSA analysis, as well as by overexpression and inhibition experiments in which NF-κB function was blocked by treatment with its inhibitor, PDTC. In addition, the overexpression of NFATc4 induces both the CS-1 and CS-2 promoters, whereas MEF2C only activates CS-1. CONCLUSION: Our present data suggest that NF-κB is required for the transcription of mouse CS-1 but not CS-2, and that the regulation of the calsarcins is mediated also by the NFAT and MEF2 transcription factors. These results provide new insights into the molecular mechanisms governing transcription in specific muscle fibre cells. The calsarcins may also serve as a valuable mechanistic tool to better understand the regulation of calcineurin signalling during muscle differentiation

Kinetic, Fluorescence Spectroscopy and Molecular Docking Studies of Tyrosinase Inhibition by Ellagic Acid

In this study, inhibition kinetics, fluorescence spectroscopy and molecular docking simulation were used to systematically investigate the inhibitory effect and mechanism of EA on mushroom tyrosinase. The in vitro study and kinetic results showed that EA significantly inhibited tyrosinase activity with a half maximal inhibitory concentration (IC50) of 0.05 mg/mL in a reversible mixed-type manner; the binding constant KI was smaller than KIS, indicating that EA bound more tightly to the free enzyme than to the enzyme-substrate complex. The fluorescence of tyrosinase was quenched statically by EA, and they combined to generate a complex through a spontaneous endothermal process, with hydrophobic interaction being the main force; there was only one binding site or class of binding sites. Simultaneous and three-dimensional fluorescence spectroscopy analysis showed that EA increased the polarity of the microenvironment of tyrosinase, decreased the hydrophobicity, and brought the Trp residues of tyrosinase closer to the binding site. Molecular docking simulation analysis further complemented and validated the above results by showing visually that EA was a mixed-type tyrosinase inhibitor, binding to the free enzyme or enzyme-substrate complex mainly through hydrophobic interactions and hydrogen bonding, ultimately leading to reduced enzyme activity. This study is of reference significance for the application of EA as a preservative in the food industry

Influence of acrylamide on ROS, Hsp27 and NF-kB in bone marrow mesenchymal stem cells

The bone marrow mesenchymal stem cells (BM-MSCs) treated with acrylamide (ACR) were used to make out the immune response to ROS, interleukin-8 and phosphorylated Hsp27 of ACR. ACR was reported as a probable human carcinogen, neurotoxic and mutagenic. BMMSCs have the capability of immunoregulation, and participate in the process of multiple immune response. It has attracted the attention of researchers that these cells have priority to move to the damaged tissue, as a kind of potential therapeutic tool for tissue repair. ACR and BMMSCs are related to immune reactions, especially those involving in tumours and cancers. However, the interaction between ACR and BMMSCs is still poorly understood. In present study, we report the influence of ACR on BMMSCs. At first, BMMSCs were disposed with 0.5mM ACR for 72 h, and then the secretion of ROS, interleukin-8, phospho- Hsp27 and NF-kB activities, apoptosis and cell cycle, respectively, were determined. The results showed that the secretion of ROS, interleukin-8 and phosph-Hsp27 increased and NF-kB was activated, while the apoptosis and cell cycle have no obvious alteration. In conclusion, ACR probably activated the NF-kB pathway in BMMSCs via oxidative stress, which may provide new insights to study the immune response and the influence mechanism of ACR

Vertical distribution of Fe, P and correlation with organic carbon in coastal sediments of Yellow Sea, Eastern China

The coastal zone is considered as a major carbon pool. Iron minerals and phosphates are vital factors affecting the amounts and occurrence of total organic carbon (TOC) in sediments. However, coupling mechanisms of iron (Fe) and phosphorous (P) in the source-sink transition of TOC in coastal sediments is poorly understood. This study characterized the distribution of Fe, P and TOC contents of three independent 170 cm sediment cores sampled from a coastal aquaculture area in the eastern Jiangsu Province, and quantified the correlations among Fe, P, median grain diameter (Dx(50)), and TOC. The results showed total phosphorus (TP) content ranges in a scope of 337.4-578.0 mg/kg, and many depths recorded moderate P eutrophication. Inorganic phosphorus (DA + IP) and biogenic apatite were the primary components of TP, accounting for 25.19–55.00 and 26.71–49.62%, respectively. The Fe contents varied from 987.9 mg/kg to 2900.7 mg/kg, in which oxidized iron (Feox) accounted for about 62.2–79.4%. In the vertical profile, the TOC was positively correlated with the contents of low-crystallinity Fe-bearing carbonates (Fecarb), high crystallinity pyrite (FePy), iron-bound phosphorus (PCDB), manganeses (Mn), and nitrogen (N), while it was negatively correlated with DA + IP, organic phosphorus (OP), and Dx(50). Based on the the partial least squares (PLS) model, we proposed that the higher FePy, Mn, magnetite (FeMag), Fecarb, PCDB, amorphous exchangeable Fe (Ex-Fe), and authigenic apatite phosphorus (Bio-P) in sediments represent the high capacity for TOC sink, whereas, higher DA + IP, and OP indicate a TOC conversion to the source. The non-siginificat indication of Feox on TOC source-sink is due to its surplus and strong reactivity relative to TOC content. These revealed correlations provide a theoretical reference for understanding and regulating the burial rate and storage of TOC by changing the input of Fe minerals and P components into coastal sediments

Wip1-dependent modulation of macrophage migration and phagocytosis

Macrophage accumulation within the vascular wall is a hallmark of atherosclerosis. Controlling macrophage conversion into foam cells remains a major challenge for treatment of atherosclerotic diseases. Here, we show that Wip1, a member of the PP2C family of Ser/Thr protein phosphatases, modulates macrophage migration and phagocytosis associated with atherosclerotic plaque formation. Wip1 deficiency increases migratory and phagocytic activities of the macrophage under stress conditions. Enhanced migration of Wip1-/- macrophages is mediated by Rac1-GTPase and PI3K/AKT signalling pathways. Elevated phagocytic ability of Wip1-/- macrophages is linked to CD36 plasma membrane recruitment that is regulated by AMPK activity. Our study identifies Wip1 as an intrinsic negative regulator of macrophage chemotaxis. We propose that Wip1-dependent control of macrophage function may provide avenues for preventing or eliminating plaque formation in atherosclerosis

One-Pot Synthesis of Biocompatible CdSe/CdS Quantum Dots and Their Applications as Fluorescent Biological Labels

We developed a novel one-pot polyol approach for the synthesis of biocompatible CdSe quantum dots (QDs) using poly(acrylic acid) (PAA) as a capping ligand at 240°C. The morphological and structural characterization confirmed the formation of biocompatible and monodisperse CdSe QDs with several nanometers in size. The encapsulation of CdS thin layers on the surface of CdSe QDs (CdSe/CdS core–shell QDs) was used for passivating the defect emission (650 nm) and enhancing the fluorescent quantum yields up to 30% of band-to-band emission (530–600 nm). Moreover, the PL emission peak of CdSe/CdS core–shell QDs could be tuned from 530 to 600 nm by the size of CdSe core. The as-prepared CdSe/CdS core–shell QDs with small size, well water solubility, good monodispersity, and bright PL emission showed high performance as fluorescent cell labels in vitro. The viability of QDs-labeled 293T cells was evaluated using a 3-(4,5-dimethylthiazol)-2-diphenyltertrazolium bromide (MTT) assay. The results showed the satisfactory (>80%) biocompatibility of as-synthesized PAA-capped QDs at the Cd concentration of 15 μg/ml

Effect of the COVID-19 pandemic on surgery for indeterminate thyroid nodules (THYCOVID): a retrospective, international, multicentre, cross-sectional study

Background Since its outbreak in early 2020, the COVID-19 pandemic has diverted resources from non-urgent and elective procedures, leading to diagnosis and treatment delays, with an increased number of neoplasms at advanced stages worldwide. The aims of this study were to quantify the reduction in surgical activity for indeterminate thyroid nodules during the COVID-19 pandemic; and to evaluate whether delays in surgery led to an increased occurrence of aggressive tumours.Methods In this retrospective, international, cross-sectional study, centres were invited to participate in June 22, 2022; each centre joining the study was asked to provide data from medical records on all surgical thyroidectomies consecutively performed from Jan 1, 2019, to Dec 31, 2021. Patients with indeterminate thyroid nodules were divided into three groups according to when they underwent surgery: from Jan 1, 2019, to Feb 29, 2020 (global prepandemic phase), from March 1, 2020, to May 31, 2021 (pandemic escalation phase), and from June 1 to Dec 31, 2021 (pandemic decrease phase). The main outcomes were, for each phase, the number of surgeries for indeterminate thyroid nodules, and in patients with a postoperative diagnosis of thyroid cancers, the occurrence of tumours larger than 10 mm, extrathyroidal extension, lymph node metastases, vascular invasion, distant metastases, and tumours at high risk of structural disease recurrence. Univariate analysis was used to compare the probability of aggressive thyroid features between the first and third study phases. The study was registered on ClinicalTrials.gov, NCT05178186.Findings Data from 157 centres (n=49 countries) on 87 467 patients who underwent surgery for benign and malignant thyroid disease were collected, of whom 22 974 patients (18 052 [78 center dot 6%] female patients and 4922 [21 center dot 4%] male patients) received surgery for indeterminate thyroid nodules. We observed a significant reduction in surgery for indeterminate thyroid nodules during the pandemic escalation phase (median monthly surgeries per centre, 1 center dot 4 [IQR 0 center dot 6-3 center dot 4]) compared with the prepandemic phase (2 center dot 0 [0 center dot 9-3 center dot 7]; p<0 center dot 0001) and pandemic decrease phase (2 center dot 3 [1 center dot 0-5 center dot 0]; p<0 center dot 0001). Compared with the prepandemic phase, in the pandemic decrease phase we observed an increased occurrence of thyroid tumours larger than 10 mm (2554 [69 center dot 0%] of 3704 vs 1515 [71 center dot 5%] of 2119; OR 1 center dot 1 [95% CI 1 center dot 0-1 center dot 3]; p=0 center dot 042), lymph node metastases (343 [9 center dot 3%] vs 264 [12 center dot 5%]; OR 1 center dot 4 [1 center dot 2-1 center dot 7]; p=0 center dot 0001), and tumours at high risk of structural disease recurrence (203 [5 center dot 7%] of 3584 vs 155 [7 center dot 7%] of 2006; OR 1 center dot 4 [1 center dot 1-1 center dot 7]; p=0 center dot 0039).Interpretation Our study suggests that the reduction in surgical activity for indeterminate thyroid nodules during the COVID-19 pandemic period could have led to an increased occurrence of aggressive thyroid tumours. However, other compelling hypotheses, including increased selection of patients with aggressive malignancies during this period, should be considered. We suggest that surgery for indeterminate thyroid nodules should no longer be postponed even in future instances of pandemic escalation.Funding None.Copyright (c) 2023 Published by Elsevier Ltd. All rights reserved

Semantic Information Retrieval over P2P Network

National audienceP2P network attracts more and more attention as an alternative to publish or accessto information, because of its advantages in scalability, decentralization and self-organization.While a lot of research has been focused on semantic query routing in information system overP2P network, little work concerns if semantic query routing can satisfy the requirement ofsemantic information retrieval, and to what extent the query routing mechanism can providethe information semantically related to users’ query. In this paper, we study the applicationof semantics in traditional information retrieval and information system over P2P network;The gap between semantic information retrieval and semantic query routing is demonstrated;Finally, the challenge of semantic information retrieval over P2P network is presented