99 research outputs found

    Investigation of the Mathematical Relationship between the Aortic Valve and Aortic Root: Implications for Precise Guidance in Aortic Valve Repair

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    Background: The study was aimed at investigating the mathematical relationship between the aortic valve and aortic root through CTA imaging-based reconstruction. Methods: We selected 121 healthy participants and analyzed the measurements of aortic root dimensions, including the sinotubular junction (SJT), ventriculo-arterial junction (VAJ), maximum sinus diameter (SD), sinus height (SH), effective height (eH) and coaptation height (cH). We also reconstructed 3-D aortic valve cusps using CTA imaging to calculate the aortic cusp surface areas. Data were collected to analyze the ratios and the correlation between aortic valve and aortic root dimensions. Results: Among healthy participants, the STJ was approximately 10% larger than the VAJ, and the SD was 1.375 times larger than the VAJ. The average eH and cH were 8.94 mm and 3.62 mm, respectively. The aortic cusp surface areas were larger in men than women. Regardless of sex, the non-coronary cusp was found to be largest, and was followed by the right coronary cusp and the left coronary cusp. Although the aortic root dimensions were also significantly larger in in men than women, the STJ to VAJ, SD to VAJ, and SH to VAJ ratios did not significantly differ by sex. The mathematical relationship between the aortic cusp surface areas and VAJ orifice area was calculated as aortic cusp surface areas Conclusions: The aortic root has specific geometric ratios. The mathematical relationship between the aortic valve and aortic root might be used to guide aortic valve repair

    Effects of microwave-enhanced pretreatment on oil shale milling performance

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    Oil shale, as an unconventional fossil fuel, exhibits unique properties compared with coal and other petroleum. Due to the nature of sedimentary rock, large amounts of inorganic mineral impurities in rock matrix reduce the grade of oil shale, whilst increase the grinding resistance. This investigation presents the effects of microwave-enhanced pretreatment on the nature of oil shale and compared with conventional preheating process. Two Chinese oil shale from Fushun and Xingsheng Deposits were grounded and sieved into a size fraction (1-1.18mm) and were cut into eighteen cube-shaped specimens respectively. The prepared samples were processed accordingly to investigate how the grindability changed, in comparison to that of raw samples, and how the fundamental chemical properties of oil shale were altered after pretreatment. Quantitive data were used to assess the effects of different pretreatment methods on oil shale milling performance in a lab-scale pulverizer along with the impacts on moisture content, chemical properties. The uniaxial compressive strength (σmax) of Fushun oil shale was reduced 63.1% and the breakage rate increased 44.9% by short exposure to microwave irradiation. In conclusion, microwave-enhanced pretreatment presents significant improvement in oil shale milling performance compared to conventional preheating process in terms of breakage rate (Si) and uniaxial compressive strength (σmax) which showed negligible alterations. © 2019 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of ICAE2018 - The 10th International Conference on Applied Energy

    CO2 gasification and pyrolysis reactivity evaluation of oil shale

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    This research focuses on the non-isothermal CO2 gasification and pyrolysis reactivity via thermogravimetric analysis. It was found that CO2 decreased activation energy of all four types of oil shale (Fushun, Jinzhou, Wulin, Xingsheng). Activation energy of XS oil shale was highly reduced from 59.86 kJ/mol to 9.48 kJ/mol. Reactivity index results showed that WL and XS oil shales were observed to be more dependent on CO2 atmosphere. Alkali metal oxide also contributed to thermal decomposition according to thermogravimetric (TG) and differential thermal analysis (DTG) curves during CO2 gasification process. Overall, CO2 atmosphere can be used to improve oil shale decomposition, especially for alkali- rich shales, while providing an efficient and effective means to convert greenhouse gases into useful fuels. © 2019 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of ICAE2018 - The 10th International Conference on Applied Energy

    The kinetics studies and thermal characterisation of biomass

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    This work aims to investigate and develop a method to evaluate and predict the combustion behaviour and combustion efficiency of different biomass commonly used in power plants via simple characterisation methods. 11 types of agricultural and industrial wastes were characterised using thermogravimetric analyser to obtain the derivative thermogravimetric (DTG) data and kinetic parameters. For the samples tested, the initiation temperatures were found to be in the range between 224.39 0 C and 260.33 0 C, whilst the local minimum temperatures between 2 peaks were within the range of 360.36 to 382.74 0 C. It was established that there is a clear, direct relationship between the pre-exponential factor and the temperature interval for the first step of combustion. This trend was apparent and recorded for the 2 heating rates tested. © 2019 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of ICAE2018 - The 10th International Conference on Applied Energy

    Risk Assessment of Etanercept in Mice Chronically Infected With Toxoplasma gondii

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    Toxoplasma gondii (T. gondii) is a zoonotic parasite that severely harms the health of the host. The cysts of T. gondii can reactivate from bradyzoites to tachyzoites, if the individual develops low or defective immunity, causing lethal toxoplasmosis. The host resists T. gondii infection by mediating Th1-type cellular immunity to generate pro-inflammatory cytokines. Tumor necrosis factor (TNF) is an important pro-inflammatory cytokine, which can induce lysosomal fusion of parasitophorous vacuole (PV) to kill parasites. Etanercept is a soluble TNF receptor fusion protein, which is widely used clinically to cure autoimmune diseases. The effects and specific molecular mechanisms of etanercept treatment on patients co-infected with autoimmune diseases and chronic toxoplasmosis are rarely reported. In our study, a mouse model of chronic infection with T. gondii and murine macrophages RAW264.7 cells infected with T. gondii were employed to investigate the impact of etanercept on the status of chronic infection. The cytokines levels and a series of phenotypic experiments in vivo and in vitro were measured. In the present study, the expression levels of TNF, IL-1β, and IL-6 were decreased and the brain cysts number was increased in mice chronically infected with T. gondii after being treated with etanercept. In vivo experiments confirmed that etanercept caused a decrease in the immune levels of the mice and activated the brain cysts, which would lead to conversion from chronic infection to acute infection, causing severe clinical and pathological symptoms. Murine macrophages RAW264.7 cells were pretreated with etanercept, and then infected with T. gondii. In vitro experiments, the expression levels of cytokines were decreased, indicating that etanercept could also reduce the cells’ immunity and promote the transformation of bradyzoites to tachyzoites, but did not affect the intracellular replication of tachyzoites. In summary, etanercept treatment could activate the conversion of bradyzoites to tachyzoites through reducing host immunity in vivo and in vitro. The results obtained from this study suggest that the use of etanercept in patients co-infected with autoimmune diseases and chronic toxoplasmosis may lead to the risk of activation of chronic infection, resulting in severe acute toxoplasmosis

    Managing Excess Lead Iodide with Functionalized Oxo‐Graphene Nanosheets for Stable Perovskite Solar Cells

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    Stability issues could prevent lead halide perovskite solar cells (PSCs) from commercialization despite it having a comparable power conversion efficiency (PCE) to silicon solar cells. Overcoming drawbacks affecting their long-term stability is gaining incremental importance. Excess lead iodide (PbI2) causes perovskite degradation, although it aids in crystal growth and defect passivation. Herein, we synthesized functionalized oxo-graphene nanosheets (Dec-oxoG NSs) to effectively manage the excess PbI2. Dec-oxoG NSs provide anchoring sites to bind the excess PbI2 and passivate perovskite grain boundaries, thereby reducing charge recombination loss and significantly boosting the extraction of free electrons. The inclusion of Dec-oxoG NSs leads to a PCE of 23.7 % in inverted (p-i-n) PSCs. The devices retain 93.8 % of their initial efficiency after 1,000 hours of tracking at maximum power points under continuous one-sun illumination and exhibit high stability under thermal and ambient conditions

    Genome-Wide Histone H3K27 Acetylation Profiling Identified Genes Correlated With Prognosis in Papillary Thyroid Carcinoma

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    Thyroid carcinoma (TC) is the most common endocrine malignancy, and papillary TC (PTC) is the most frequent subtype of TC, accounting for 85–90% of all the cases. Aberrant histone acetylation contributes to carcinogenesis by inducing the dysregulation of certain cancer-related genes. However, the histone acetylation landscape in PTC remains elusive. Here, we interrogated the epigenomes of PTC and benign thyroid nodule (BTN) tissues by applying H3K27ac chromatin immunoprecipitation followed by deep sequencing (ChIP-seq) along with RNA-sequencing. By comparing the epigenomic features between PTC and BTN, we detected changes in H3K27ac levels at active regulatory regions, identified PTC-specific super-enhancer-associated genes involving immune-response and cancer-related pathways, and uncovered several genes that associated with disease-free survival of PTC. In summary, our data provided a genome-wide landscape of histone modification in PTC and demonstrated the role of enhancers in transcriptional regulations associated with prognosis of PTC

    Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR

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    Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials (mu_B > 500 MeV), effects of chiral symmetry, and the equation-of-state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2022, in the context of the worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal
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