We report an in-situ neutron diffraction study of a large format pouch battery cell. The succession of Li-Graphite intercalation phases was fully captured under an 1C charge-discharge condition ...(i.e., charge to full capacity in 1 hour). However, the lithiation and dilithiation pathways are distinctively different and, unlike in slowing charging experiments with which the Li-Graphite phase diagram was established, no LiC₂₄ phase was found during charge at 1C rate. Approximately 75 mol. % of the graphite converts to LiC₆ at full charge, and a lattice dilation as large as 4% was observed during a charge-discharge cycle. Our work demonstrates the potential of in-situ, time and spatially resolved neutron diffraction study of the dynamic chemical and structural changes in "real-world" batteries under realistic cycling conditions, which should provide microscopic insights on degradation and the important role of diffusion kinetics in energy storage materials.
A universal elastic-plastic model (UEM) to describe the nonlinear relation among energy, load, displacement and Hollomon constitutive parameters is proposed for various structural components (SCs) by ...equivalent energy principle (EEP). The model contains only four parameters related to the effective volume of deformed region and the equivalent strain at energy center. A simple approach to determine these parameters is introduced by five times FEA (finite element analysis) calculations. Then, a systematical verification is conducted with both FEA and some experiments. For pure torsion SC, three bending SCs, two indentation SCs, ring compression SC, compact tension SC and small punch test SC, the universal model predicted elastic-plastic load-displacement curves are excellently consistent with the FEA results. Reversely, it can be applied in predicting the Hollomon parameters of materials when the load-displacement curves are known from FEA or experiments.
In traditional indentation test methods for obtaining Norton's law of creep materials, an empirical correlation formula represents the relationship between the indentation strain rate and the ...uniaxial reference strain rate or indentation displacement rate. This study proposes an equivalent method for representative volume elements (RVE) of creep materials from a complex stress state to a simple stress state. Considering Norton's law as a constitutive relationship based on the equivalent method of stress state, a semi-analytical model describing the creep displacement vs. time relationship of flat cylindrical indentation (flat indentation) and a method for determining the parameters of the model were established under constant load conditions in this investigation. The finite element analysis (FEA), creep test results of zinc alloy ZA27, and results in the current literature were used to verify the semi-analytical creep model. The results showed that Norton's law and the displacement rate predicted by different indentation creep models are relatively close, and the partial results predicted by the new model are slightly better than those obtained by methods reported in the literature.
Beryllium and its compounds are systemic toxicants that mainly accumulate in the lungs. As a regulator of gene expression, microRNAs (miRNAs) were involved in some lung diseases. This study aimed to ...analyze the levels of some inflammatory cytokine and the differential expressions of miRNAs in human bronchial epithelial cells (16HBE) induced by beryllium sulfate (BeSO4) and to further explore the biological functions of differentially expressed miRNAs. The profile of miRNAs in 16HBE cells was detected using the high‐throughput sequencing between the control groups (n = 3) and the 150 μmol/L of BeSO4‐treated groups (n = 3). Bioinformatics analysis of differentially expressed miRNAs was performed, including the prediction of target genes, Gene Ontology (GO) analysis, and the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. Quantitative real‐time polymerase chain reaction (qRT‐PCR) was applied to verify some damage‐related miRNAs. We found that BeSO4 can increase the levels of some inflammatory cytokine such as interleukin‐10 (IL‐10), tumor necrosis factor‐alpha (TNF‐α), interferon‐γ (IFN‐γ), inducible nitric oxide synthase (iNOS), and cyclooxygenase‐2 (COX‐2). And BeSO4 altered miRNAs expression of 16HBE cells and a total of 179 differentially expressed miRNAs were identified, including 88 upregulated miRNAs and 91 downregulated miRNAs. The target genes predicted by 28 dysregulated miRNAs were mainly involved in the transcription regulation, signal transduction, MAPK, and VEGF signaling pathway. The qRT‐PCR verification results were consistent with the sequencing results. miRNA expression profiling in 16HBE cells exposed to BeSO4 provides new insights into the toxicity mechanism of beryllium exposure.
Beryllium and its compounds are systemic toxicants that mainly accumulate in the lungs. As a regulator of gene expression, microRNAs (miRNAs) were involved in some lung diseases. This study aimed to analyze the levels of some inflammatory cytokine and the differential expressions of miRNAs in human bronchial epithelial cells (16HBE) induced by beryllium sulfate (BeSO4) and further explore the biological functions of differentially expressed miRNAs. We found that BeSO4 can increase the levels of some inflammatory cytokine such as interleukin‐10 (IL‐10), tumor necrosis factor‐alpha (TNF‐α), interferon‐γ (IFN‐γ), inducible nitric oxide synthase (iNOS), and cyclooxygenase‐2 (COX‐2). And BeSO4 altered miRNAs expression of 16HBE cells and a total of 179 differentially expressed miRNAs were identified, including 88 up‐regulated miRNAs and 91 down‐regulated miRNAs. The target genes predicted by 28 dysregulated miRNAs were mainly involved in the transcription regulation, signal transduction, MAPK, and VEGF signaling pathway. miRNA expression profiling in 16HBE cells exposed to BeSO4 provides new insights into the toxicity mechanism of beryllium exposure.
Based on the equivalent energy principle (EEP), an explicit theoretical model between conical indentation response and uniaxial mechanical parameters is derived. In order to avoid the defect that ...sharp indentation technique always requires at least two indenters to penetrate different positions successively and the compatibility between the indentation points, an energy-based combined dual-conical indentation (CDI) model is created by using a novel combined indenter with dual conical surfaces. A typical piecewise load-depth curve is observed during the combined dual-conical indentation and two characteristic loading curvatures are respectively acquired from the single penetration response. Numerical verifications for the novel method are conducted by finite element analysis (FEA) within a large range of elastic–plastic materials. For six kinds of metallic materials, based on the stable load-depth curves obtained by the combined indentation tests, the uniaxial stress–strain curves as well as the yield stress, strain hardening exponent and tensile strength are predicted by CDI model. The results show that the predictions of CDI method are consistent with those from uniaxial tension. The novel method is expected to be more convenient for mechanical testing and evaluation of materials or structures.
Abstract
Aims
The mechanisms underlying ageing-induced vascular remodelling remain unclear. This study investigates the role and underlying mechanisms of the cytoplasmic deacetylase sirtuin 2 (SIRT2) ...in ageing-induced vascular remodelling.
Methods and results
Transcriptome and quantitative real-time PCR data were used to analyse sirtuin expression. Young and old wild-type and Sirt2 knockout mice were used to explore vascular function and pathological remodelling. RNA-seq, histochemical staining, and biochemical assays were used to evaluate the effects of Sirt2 knockout on the vascular transcriptome and pathological remodelling and explore the underlying biochemical mechanisms. Among the sirtuins, SIRT2 had the highest levels in human and mouse aortas. Sirtuin 2 activity was reduced in aged aortas, and loss of SIRT2 accelerated vascular ageing. In old mice, SIRT2 deficiency aggravated ageing-induced arterial stiffness and constriction–relaxation dysfunction, accompanied by aortic remodelling (thickened vascular medial layers, breakage of elastin fibres, collagen deposition, and inflammation). Transcriptome and biochemical analyses revealed that the ageing-controlling protein p66Shc and metabolism of mitochondrial reactive oxygen species (mROS) contributed to SIRT2 function in vascular ageing. Sirtuin 2 repressed p66Shc activation and mROS production by deacetylating p66Shc at lysine 81. Elimination of reactive oxygen species by MnTBAP repressed the SIRT2 deficiency–mediated aggravation of vascular remodelling and dysfunction in angiotensin II–challenged and aged mice. The SIRT2 coexpression module in aortas was reduced with ageing across species and was a significant predictor of age-related aortic diseases in humans.
Conclusion
The deacetylase SIRT2 is a response to ageing that delays vascular ageing, and the cytoplasm–mitochondria axis (SIRT2–p66Shc–mROS) is important for vascular ageing. Therefore, SIRT2 may serve as a potential therapeutic target for vascular rejuvenation.
Structured Graphical Abstract
Structured Graphical Abstract
The epigenetic regulator sirtuin 2 (SIRT2) governs a cytoplasm–mitochondria signal to repress vascular ageing. Ageing reduces SIRT2 protein levels and activity, which results in the hyperacetylation and activation of the adaptor protein p66Shc and production of mitochondrial reactive oxygen species (mROS), which subsequently reprogrammes the vascular transcriptome to aggravate ageing-induced vascular remodelling and diseases. The circulating SIRT2 may serve as a prognostic biomarker for ageing-related vascular diseases, and the cytoplasm–mitochondria axis SIRT2–p66Shc–mROS could be targeted for treating ageing-related vascular diseases.
•A semi-analytical model about load, displacement and materials properties of funnel sheet and ring sheet specimens is established.•Conversion equations are obtained for nominal stress/strain and ...true stress/strain.•The small specimens are designed to predict Manson-Coffin law of materials.
In this study, a novel method for low-cycle-fatigue (LCF) tests on small funnel and Ring specimens to obtain the Manson–Coffin law of materials is proposed based on the median energy equivalence principle. It includes a method for solving the cyclic stress-strain relationship of the material according to the cycling stability curve of load amplitude–displacement amplitude, and another method for acquiring the conversion relationship between the measuring displacement amplitudes and local strain amplitudes of the specimen. LCF experiments under constant displacement amplitude loading were performed on small funnel and Ring specimens, as well as standard straight-round bar specimens of the two materials, G115 and 16Mn. The results indicated that the uniaxial cyclic stress–strain relationship and Manson–Coffin law results of the G115 and 16Mn materials obtained by the new method were highly consistent with those obtained by the traditional standard method.
•Propose the load-displacement, J integral-load relations etc. of cracked components based on energy equivalent principle.•Examine the validity of semi-analytical equations by finite element ...analysis.•Obtain J resistance curves of ductile materials according to semi-analytical expressions.•Determine the J resistance curves of Cr2Ni2MoV for CT specimens and 26NiCrMoV11-5 for CIET specimens.
Four kinds of configurations represented by compact tension (CT) specimen, single edge-notched bending (SEB) specimen, single edge-notched tension (SET) specimen and C-shaped inside edge-notched tension (CIET) specimen were simulated by ANSYS 14.5 under plane strain conditions and three dimension (3D) conditions for determining the parameters of load-displacement, J integral-load etc. semi-analytical expressions. And a novel semi-analytical method is proposed to obtain J resistance curves of ductile materials on the basis of equivalent energy principle. In order to examine the validity of semi-analytical expressions, the fundamental curves (e.g., load-displacement, J integral-load curves etc.) predicted by the expressions were compared with the curves obtained from finite element analysis (FEA). It can be observed that they agree well with each other. Moreover, the real-time crack length and J integral of growing cracked specimen at arbitrary loading points can be determined through solving the explicit expressions. And a corrected formula of J integral was obtained in order to consider the influence of crack growth of sharp cracked specimen. Further, the J resistance curves of Cr2Ni2MoV for CT specimens and 26NiCrMoV11-5 for CIET specimens were successfully obtained via the new method, which show good agreement with the results determined by traditional normalization method. And the crack lengths predicted by the method match with those obtained by physical measurement on the fracture surface of specimens. Meanwhile, the critical JC which represents the sharp cracked specimen beginning to growth can also be easily determined.
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Abstract
Background
The present study aimed to compare the efficacy and safety profiles of microspheres versus (vs.) polyvinyl alcohol (PVA) for bronchial artery embolization (BAE) treatment in ...patients with hemoptysis.
Methods
Totally, 152 patients with hemoptysis who were about to receive BAE treatment were consecutively enrolled and divided into microspheres group (N = 62) and PVA group (N = 90). Technical success and clinical success were assessed after BAE procedure, and the hemoptysis-recurrence status, survival status and adverse events were recorded during follow-up.
Results
Technical success rates were both 100% in microspheres group and PVA group; clinical success rate (96.8% vs. 100.0%,
P
= 0.165), 6-month (9.7% vs. 7.8%,
P
= 0.681) and 1-year (9.7% vs. 8.9%,
P
= 0.869) hemoptysis recurrence rate, 6-month (4.8% vs. 2.2%,
P
= 0.374) and 1-year (4.8% vs. 3.3%,
P
= 0.639) mortality were similar between microspheres group and PVA group. Furthermore, hemoptysis-free survival (
P
= 0.488) and overall survival (
P
= 0.321) were of no difference between two groups. In addition, all adverse events were mild, and there was no difference of adverse events between two groups (all
P
> 0.05). These data were validated by further multivariate regression analysis.
Conclusions
Microspheres present comparable efficacy and safety profiles compared with PVA for the BAE treatment in patients with hemoptysis, providing evidence for embolic agent selection.
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