| 1. |
- Barghouth, Mohammad, et al.
(author)
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The structure of insulin granule core determines secretory capacity being reduced in type-2 diabetes
- 2022
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Other publication (other academic/artistic)abstract
- Exocytosis in excitable cells is essential for their physiological functions. Although the exocytotic machinery controlling cellular secretion has been well investigated, the function of the vesicular cargo, i.e. secretory granular content remains obscure. Here we combine dSTORM imaging and single-domain insulin antibody, to dissect the in situ structure of insulin granule cores (IGCs) at nano level. We demonstrate that the size and shape of the IGCs can be regulated by the juxta-granular molecules Nucleobindin-2 and Enolase-1, that further contribute to the stimulated insulin secretion. IGCs located at the plasma membrane are larger than those in the cytosol. The IGCs size is decreased by ∼20% after glucose stimulation due to the release of the peripheral part of IGCs through incomplete granule fusion. Importantly, the reduction of the IGCs size is also observed in non-stimulatory pancreatic β-cells from diabetic db/db mice, Akita (Ins2+/-) mice and human Type-2 diabetic donors, in accordance with impaired secretion. These findings overall highlight the structure of exocytotic insulin cores as a novel modality amenable to targeting in the stimulated exocytosis in β-cells with impaired insulin secretion.Competing Interest StatementThe authors have declared no competing interest.
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| 2. |
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| 3. |
- Chen, Xiaoping, et al.
(author)
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Risk factors for the delayed viral clearance in COVID‐19 patients
- 2021
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In: The Journal of Clinical Hypertension. - : John Wiley & Sons. - 1524-6175 .- 1751-7176. ; 23:8, s. 1483-1489
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Journal article (peer-reviewed)abstract
- Comorbidities are important for the disease outcome of COVID-19, however, which underlying diseases that contribute the most to aggravate the conditions of COVID-19 patients are still unclear. Viral clearance is the most important laboratory test for defining the recovery of COVID-19 infections. To better understand which underlying diseases that are risk factors for delaying the viral clearance, we retrospectively analyzed 161 COVID-19 clinical cases in the Zhongnan Hospital of Wuhan University, Wuhan, China between January 5 and March 13, 2020. The demographic, clinical and laboratory data, as well as patient treatment records were collected. Univariable and multivariable analysis were performed to explore the association between delayed viral clearance and other factors by using logistic regression. Survival analyses by Kaplan-Meier and Cox regression modeling were employed to identify factors negatively influencing the viral clearance negatively. We found that hypertension and intravenous immunoglobulin adversely affected the time of viral RNA shedding. Hypertension was the most important risk factor to delay the SARS-CoV-2 virus clearance, however, the use of Angiotensin-Converting Enzyme Inhibitors(ACEI)/Angiotensin Receptor Blockers(ARB) did not shorten the time for virus clearance in these hypertensive patients’ virus clearance. We conclude that patients having hypertension and intravenous immunoglobulin may delay the viral clearance in COVID-19 patients.
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| 4. |
- Ji, Xinyu, et al.
(author)
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Jet array impingement boiling in compact space for high heat flux cooling
- 2023
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In: Applied Thermal Engineering. - : Elsevier BV. - 1359-4311. ; 219
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Journal article (peer-reviewed)abstract
- To achieve high heat flux cooling, a distributed confined jet array impingement boiling device was designed and tested by using HFE-7100 as working fluid. The experimental study on the heat transfer characteristics was conducted on smooth silicon surface and micro-pin-finned surfaces with mass flux ranging from 760 ∼ 3040 kg/m2·s under atmospheric pressure and an inlet subcooling of 40 K. The results indicated that with the increase of the jet velocity, nucleate boiling was suppressed, and the forced convection heat transfer was enhanced. The heat transfer was greatly intensified on micro-pin-finned surfaces with a maximum increase of the heat transfer coefficient of 220 % due to the increase in specific surface area and the number of nucleation sites. Moreover, the critical heat flux (CHF) can reach 280 W/cm2. The mechanism of CHF improvement was analyzed. The two-phase flow structure within the confinement space and capillary wicking effect of the micro-pin-finned surface are superimposed, resulting in two distinct CHF mechanisms. A new correlation with a mean absolute error of 3.5 % for predicting the heat transfer coefficient of the jet impingement boiling was proposed by considering the effect of micro-pin–fin structure on heat transfer.
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| 5. |
- Ji, Xinyu, et al.
(author)
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Two-phase flow characteristics and visualization of distributed confined array jet boiling
- 2024
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In: Case Studies in Thermal Engineering. - 2214-157X. ; 57
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Journal article (peer-reviewed)abstract
- Confined array jet boiling can achieve high heat flux in a compact space and its flow resistance characteristics are critical to the design of cooling systems. The boiling images of distributed confined jet of HFE-7100 is recorded by a high-speed camera in this study. The effects of jet mass flux, jet height and surface structure of two-phase jet flow characteristics on micro-pin-finned surfaces are studied. A benefit from the distributed configuration of the jet array, in contrast to previous studies, is that the jet boiling pressure drop is independent of the heat flux, but only related to the jet mass flux. The effect of the surface structure on the pressure drop is negligible. Jet flow instability will be triggered by intermittently blockage of the jet inlet and outlet by large vapor masses in certain heated surfaces. Reducing the jet height can suppress two-phase flow instabilities while keeping the pressure drop almost constant and the CHF to slightly increase. The COP of distributed jet impingement boiling cooler proposed in this work can be up to 6 times higher than that of the conventional jet boiling cooler, and more than 2 times higher that of the microchannel heat sink.
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| 6. |
- Ma, Xiaoping, et al.
(author)
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Application of Ti Microalloying in a Thin-Slab-Cast Medium-Carbon Steel
- 2021
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In: Iron & Steel Technology. - : Association for Iron and Steel Technology. - 1547-0423. ; 18:7, s. 178-188
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Journal article (peer-reviewed)abstract
- Addition of 0.035 wt.% Ti into a steel with 0.23 wt.% C and 1.3 wt.% Mn was designed to produce steels for axle housing application. The production of 11-mm-thick coils was carried out in a Direction Strip Production Complex strip mill. The present studies focus on structureproperties correlation of the steels as-rolled and after normalizing at 750°C. The precipitation, partial dissolution and re-precipitation behavior of TiC along with microstructure refinement in as-rolled steel and after normalizing are analyzed using electron microscopes. The results lay the foundation for application of Ti microalloying in heat-treated medium-carbon steels.
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| 7. |
- Ma, Xiang, et al.
(author)
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Flow boiling frictional pressure drop inside micro/mini-channels : A new general model and experimental investigation
- 2024
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In: Applied Thermal Engineering. - 1359-4311. ; 247
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Journal article (peer-reviewed)abstract
- In this study, a novel general model for flow boiling frictional pressure drop inside micro/mini-channels was proposed based on theoretical analysis and experimental evaluation. Experiments were conducted to obtained flow boiling pressure drop of deionized water, HFE7100 and R134a in micro-channels under various experimental conditions. Then, a wide database from 33 previous literatures consists 3854 experimental data points covering 11 different working fluids, e.g., carbon dioxide, new electronic fluorinated solutions, refrigerants and deionized water, among others, and the operation conditions were as following: system temperature of −40–90 ℃, saturated pressure of 101–3970 kPa, hydraulic diameter of 0.1–2.6 mm, liquid subcooling of 5–75 K, mass flux of 50–3000 kg/(m2·s), heat flux of 0–4000 kW/m2, liquid-only Reynolds number of 40–12,000, vapor quality of 0–1, and reduced pressure of 0.0045–0.5380 in the database. Both the Reynolds numbers of vapor and liquid were calculated using the hydraulic diameter and vapor quality. The present data points were evaluated by 20 existing classical models (including the homogeneous and separated flow ones) for the flow boiling frictional pressure drop. However, the predictions of these models for the present data points had low accuracy, especially for the subcooled points at low vapor quality. Therefore, a more accurate prediction model was developed based on the present database by distinguishing the subcooled and saturated boiling. This novel prediction model can predict 75.4 % and 89.7 % of data points within ±30 % and ±50 % error bands, its mean absolute percent error (MAPE) is 19.23 %, which shows good predictive ability. Besides, the reliability of the new model was also further verified with our experimental results.
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| 8. |
- Qiu, Yizhi, et al.
(author)
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Proximity to oilseed rape fields affects plant pollination and pollinator-mediated selection on a co-flowering plant on the Tibetan Plateau
- 2023
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In: Evolutionary Applications. - : Wiley. - 1752-4571. ; 16:4, s. 814-823
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Journal article (peer-reviewed)abstract
- The ecological effects of mass-flowering crops on pollinator abundance and species richness of neighbouring habitats are well established, yet the potential evolutionary consequences remain unclear. We studied effects of proximity to a mass-flowering crop on the pollination of local co-flowering plants and on patterns of natural selection on a pollination-generalised plant on the Tibetan Plateau. We recorded pollinator visitation rates and community composition at different distances (near vs. far) to oilseed rape (Brassica napus) fields in two habitat types and quantified pollinator-mediated selection on attractive traits of Trollius ranunculoides. The proximity to oilseed rape increased pollinator visitation in neighbouring alpine meadows and changed pollinator composition in neighbouring shrub meadows. Trollius ranunculoides in the alpine meadow near oilseed rape received three times more pollinator visits (mainly bees) and consequently had a 16.5% increase in seed set but also received slightly more heterospecific pollen per stigma. In contrast, pollinator visitation to T. ranunculoides in the shrub meadow near oilseed rape was three times lower (mainly flies), leading to a 10.7% lower seed despite no effect on pollen deposition. The proximity to the oilseed rape field intensified pollinator-mediated selection on flower size and weakened selection on flower height of T. ranunculoides in the alpine meadow but did not affect phenotypic selection on either trait in the shrub meadow. Our study highlights context-dependent variation in plant–pollinator interactions close to mass-flowering oilseed rape, suggesting potential effects on the evolution of flower traits of native plants through altered pollinator-mediated selection. However, context dependence may make these effects difficult to predict.
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| 9. |
- Yu, Yang, et al.
(author)
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Effect of the heating rate on the thermal explosion behavior and oxidation resistance of 3D-structure porous NiAl intermetallic
- 2022
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In: Materials Characterization. - : Elsevier BV. - 1044-5803. ; 190
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Journal article (peer-reviewed)abstract
- Porous NiAl intermetallic compounds demonstrate great potential in various applications by their high porosity and excellent oxidation resistance. However, to obtain a controllable NiAl intermetallic structure by tuning different process parameters remains unclear. In this work, porous NiAl intermetallic compounds were fabricated by economic and energy-saving thermal explosion (TE) reaction. The relationship between microstructure and process parameters was revealed using three-dimensional X-ray microscopy (3D-XRM) with high resolution and non-destructive characteristics. The geometrical features and quantitative statistics of the porous NiAl obtained at different heating rates (2, 10, 20 °C min−1) were compared. The result of the closed porosity calculation showed that a lower heating rate (2 °C min−1) promoted the Kirkendall reaction between Ni and Al, resulting in a high closed porosity (5.25%). However, at a higher heating rate (20 °C min−1), a homogeneous NiAl phase was observed using the threshold segmentation method, indicating uniform and complete TE reaction can be achieved at a high heating rate. The result of the 3D fluid simulation showed that the sample heated at 10 °C min−1 had the highest permeability (2434.6 md). In this study, we systematically investigated the relationship between the heating rates and properties of the porous NiAl intermetallic, including the phase composition, porosity, exothermic mechanism, oxidation resistance, and compression resistance. Our work provides constructive directions for designing and tailoring the performance of porous NiAl intermetallic compounds.
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| 10. |
- Yu, Yang, et al.
(author)
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Research of TE behaviour and compression property of porous Ni–Al–Cr intermetallic compounds in the β phase region
- 2023
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In: Journal of Materials Research and Technology. - : Elsevier Editora Ltda. - 2238-7854 .- 2214-0697. ; 25, s. 3537-3550
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Journal article (peer-reviewed)abstract
- Ni–Al–Cr alloys in the β phase (B2–NiAl) region exhibit remarkable stability and mechanical property. Through thermal explosion (TE) reaction, Ni–Al–Cr intermetallic compounds with high porosity can be obtained. In this study, the focus lies on analyzing the macroscopic morphology, microstructure, phase distribution, TE behaviour, and the mechanical property of porous Ni–Al–Cr in the β phase region. Following the TE reaction, the Al-rich sintered product demonstrates a uniform phase composition and high porosity, reaching 44.39%. The vigorous TE reaction promotes the formation of interconnected pores, while the high porosity structure compromises the mechanical properties of the sample. Conversely, the Al-poor sintered product, due to a moderate TE reaction and low porosity structure, maintains its complete morphology and exhibits excellent compression resistance (yield stress reaching 538 MPa). This study offers valuable insights for the fabrication of porous Ni–Al–Cr materials with exceptional structure and performance.
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