86 research outputs found

    The genetic mineralogical characteristics of fish otoliths and their environmental typomorphism

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    Otolith is a typical biomineral carrier growing on insides of fish skull with prominent zoning structure formed by alternating layers of protein and calcium carbonate around the nucleus. The zoning number and the thickness of the rhythmic zone can reflect the age and the growing velocity. The δ18O values of the calcium carbonate are indicators of the temperature of the water where the fish lives. The geometry, color, common and trace elements, oxygen and carbon isotopes of the zones can be employed effectively to classify the species, trace the source, migration habits, nutrition level of the fish and the variation of the ocean environment, in order to predict the environmental variation trend of related waters and make strategic plan for fishery production. Thermoluminescence technique can be taken as a new tool in the investigation of fish otolith to describe the heavy metal pollution of related waters, and the thermoluminescence parameters can be used to deduce the source and manage fishery resources.Key words: Fish otoliths, age, temperature, species, migration, water environment

    Thermoluminescence (TL) analysis for otoliths of the wild carps (cyprinoid) from Baiyangdian Lake and Miyun Reservoir: Some implications for monitoring water environment

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    Otolith is a typical biomineral carrier growing on insides of fish skull with prominent zoning structure formed by alternating layers of protein and calcium carbonate growing around the nucleus. Even though thermoluminescence (TL) analysis on biomineral has been widely used to measure the radiation exposure in the recent twenty years, the TL characteristics of the fish otolith have not yet been reported in literature. TL characteristics of otoliths from the wild carps (cyprinoid) living in the Baiyangdian Lake, Hebei Province and Miyun Reservoir, Beijing City was first studied, and the differences of energy gap (E) between the fish otoliths in the two waters have also been discussed in this paper. The experimental results indicated that TL curve parameters: peak temperature (Tp), luminous intensity (I), integrated intensity (S) and middle width (Wm) for the glow curves of the cyprinoid otoliths from Baiyangdian Lake are greater than those from Miyun reservoir, and the stability of the formers’ TL curve parameters value and energy gap (E) was weaker than the latter. In comparison to the Miyun Reservoir, the analysis manifested that the electrons and vacancies trapped in the otoliths from Baiyangdian Lake are more likely to escape. According to the investigation, the contaminative degree and eutrophication in the water of Baiyangdian Lake was heavier than that of Miyun Reservoir. Therefore, the characteristics of TL growth curves of the cyprinoid otoliths is quite sensitive to heavier contaminated and less contaminated water, and this could be regarded as an important typomorphic biomineral for monitoring the contaminative degree and environment change of the water.Keywords: Cyprinoid otoliths, thermoluminescence, water environment, typomorphic minera

    Altering the Alkaline Metal Ions in Lepidocrocite-Type Layered Titanate for Sodium-Ion Batteries

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    The relatively large ionic radius of the Na ion is one of the primary reasons for the slow diffusion of Na ions compared to that of Li ions in de/intercalation processes in sodium-ion batteries (SIBs). Interlayer expansion of intercalation hosts is one of the effective techniques for facilitating Na-ion diffusion. For most ionic layered compounds, interlayer expansion relies on intercalation of guest ions. It is important to investigate the role of these ions for material development of SIBs. In this study, alkali-metal ions (Li+, Na+, K+, and Cs+) with different sizes were intercalated into lepidocrocite-type layered titanate by a simple ion-exchange technique to achieve interlayer modulation and those were then evaluated as anode materials for SIBs. By controlling the intercalated alkaline ion species, basal spacings of layered titanates (LTs) in the range of 0.68 to 0.85 nm were obtained. Interestingly, the largest interlayer spacing induced by the large size of Cs did not yield the best performance, while the Na intercalated layered titanate (Na-ILT) demonstrated a superior performance with a specific capacity of 153 mAh g–1 at a current density of 0.1 A g–1. We found that the phenomena can be explained by the high alkaline metal ion concentration and the efficient utilization of the active sites in Na-ILT. The detailed analysis indicates that large intercalating ions like Cs can hamper sodium-ion diffusion although the interlayer spacing is large. Our work suggests that adopting an appropriate interlayer ion species is key to developing highly efficient layered electrode materials for SIBs

    Efficacy and safety of polymyxin E sulfate in the treatment of critically ill patients with carbapenem-resistant organism infections

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    ObjectivePolymyxins are currently the last line of defense in the treatment of carbapenem-resistant organisms (CRO). As a kind of polymyxin available for clinical use in China, we aim to explore the efficacy and safety of colistin sulfate (Polymyxin E sulfate, PES) in this study.MethodsThis real-world retrospective study included 119 patients diagnosed with CRO infection and treated with PES for more than 72 h, from May 2020 to July 2022 at West China Hospital. The primary outcome was clinical efficacy at the end of treatment, and secondary outcomes included microbial response, in-hospital mortality and incidence of nephrotoxicity.ResultsThe effective clinical and microbiological responses were 53.8% and 49.1%, respectively. And the in-hospital mortality was 27.7%. Only 9.2% of patients occurred with PES-related nephrotoxicity. Multivariate analysis revealed that duration of PES was an independent predictor of effective therapy, while age-adjusted Charlson comorbidity index (aCCI) and post-treatment PCT(p-PCT) were independent risk factors for poor outcome.ConclusionsPES can be a salvage treatment for CRO-induced infections with favorable efficacy and low nephrotoxicity. The treatment duration of PES, aCCI and p-PCT were factors related to the clinical effectiveness of PES

    High Frequency of CD4+CXCR5+ TFH Cells in Patients with Immune-Active Chronic Hepatitis B

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    BACKGROUND: T follicular helper (TFH) cells are a special subpopulation of T helper cells and can regulate humoral immune responses. This study examined whether the frequency of CD4(+)CXCR5(+) TFH cells could be associated with active immunity in chronic hepatitis B (CHB) patients. METHODOLOGY AND FINDINGS: The frequencies of peripheral blood CD4(+)CXCR5(+) TFH cells, inducible T cell costimulator (ICOS), and/or programmed death 1 (PD-1) positive CD4(+)CXCR5(+) TFH cells in immune-active (IA), immune-tolerant (IT) CHB, and healthy controls (HC) were characterized by flow cytometry analysis. The effect of adevofir dipivoxil treatment on the frequency of CD4(+)CXCR5(+) TFH cells, the concentrations of serum IL-2, IFN-γ, TNF-α, IL-4, IL-6, IL-10, IL-21, ALT, AST, HBsAg, HBsAb, HBeAg, HBeAb and HBV loads in IA patients were determined. The potential association of the frequency of CD4(+)CXCR5(+) TFH cells with clinical measures was analyzed. In addition, the frequency of splenic and liver CD4(+)CXCR5(+) TFH cells in HBV-transgenic mice was examined. We found that the frequency of CD4(+)CXCR5(+) TFH cells in IA patients was significantly higher than that of IT patients and HC, and the percentages of CD4(+)CXCR5(+) TFH in IA patients were positively correlated with AST. Furthermore, the percentages of ICOS(+), PD-1(+), and ICOS(+)PD-1(+) in CD4(+)CXCR5(+) TFH cells in CHB patients were significantly higher than that of HC. Treatment with adefovir dipivoxil reduced the frequency of CD4(+)CXCR5(+) TFH, PD-1(+)CD4(+)CXCR5(+) TFH cells and the concentrations of HBsAg and HBeAg, but increased the concentrations of HBsAb, HBeAb, IL-2 and IFN-γ in IA patients. Moreover, the frequency of splenic and liver CD4(+)CXCR5(+) TFH cells in HBV-transgenic mice was higher than that of wild-type controls. CONCLUSIONS: These data indicate that CD4(+)CXCR5(+) TFH cells may participate in the HBV-related immune responses and that high frequency of CD4(+)CXCR5(+) TFH cells may be a biomarker for the evaluation of active immune stage of CHB patients

    Cracks, microcracks and fracture in polymer structures: Formation, detection, autonomic repair

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    The first author would like to acknowledge the financial support from the European Union under the FP7 COFUND Marie Curie Action. N.M.P. is supported by the European Research Council (ERC StG Ideas 2011 n. 279985 BIHSNAM, ERC PoC 2015 n. 693670 SILKENE), and by the EU under the FET Graphene Flagship (WP 14 “Polymer nano-composites” n. 696656)

    A Novel RLWE-Based Anonymous Mutual Authentication Protocol for Space Information Network

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    Currently, space information network (SIN) has become an increasingly important role in real life. As a large heterogeneous wireless network, SIN can better provide global mobile services to users anytime and anywhere, even in extreme geographic environments. In addition, there is no need to build the communication base-stations every few kilometers on the ground to ensure high service quality, which greatly reduces the construction costs and can be used as an economical communication method in sparsely populated areas. So there is a trend that more and more end users are more likely to get SIN services than traditional terrestrial cellular networks. However, due to the openness and publicity of the satellite wireless channel and the limited resources of the satellite nodes, the privacy and security cannot be perfectly guaranteed and may even be vulnerable to attacks initiated by the adversary such as replay attacks, impersonation attacks, and eavesdropping attacks. To improve the access security of SIN, researchers have proposed a series of authentication protocols based on different cryptographic assumptions. Nevertheless, existing research shows that these protocols cannot meet the requirements of higher and higher security and short authentication delay. In addition, these protocols are mainly based on public key cryptography mechanisms such as DLP and ECDLP, which can be solved by postquantum computers in polynomial time, so these protocols will no longer be secure. To solve the vulnerability of these protocols, in this paper, we propose a new RLWE-based anonymous mutual authentication and key agreement protocol, which guarantees higher security with low computational overhead even in the postquantum era. Detailed security analysis shows that our protocol meets security requirements and is resistant to a variety of known attacks. Besides, combining security comparison and performance analysis, our proposed protocol is more practical than other protocols in SIN
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