Numerical simulations have been performed to analyze the characteristics of heat transfer and air flow in the solar chimney power plant system with an energy storage layer. Different mathematical ...models for the collector, the chimney and the energy storage layer have been established, and the effect of solar radiation on the heat storage characteristic of the energy storage layer has been analyzed. The numerical simulation results show that: (1) the heat storage ratio of the energy storage layer decreases firstly and then increases with the solar radiation increasing from 200
W/m
2 to 800
W/m
2; (2) the relative static pressure decreases while the velocity increases significantly inside the system with the increase of solar radiation; (3) the average temperature of the chimney outlet and the energy storage layer may increase significantly with the increase of solar radiation. In addition, the temperature gradient of the storage medium may increase, which results in an increase of energy loss from the bottom of the energy storage layer.
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GEOZS, IJS, IMTLJ, KISLJ, NUK, OILJ, SAZU, SBCE, UL, UM, UPCLJ, UPUK
Bone resorption relies on the extracellular acidification function of vacuolar (V‐) ATPase proton pump(s) present in the plasma membrane of osteoclasts. The exact configuration of osteoclast‐specific ...V‐ATPases remains largely unknown. In this study, we found that Atp6v0d2 (d2), an isoform of the d subunit in the V‐ATPase, showed 5‐fold higher expression than that of Atp6v0d1 (d1) in mature osteoclasts, indicating a potential function in osteoclastic bone resorption. When d2 was depleted at an early stage of RANKL‐induced osteoclast differentiation in vitro, formation of multinucleated cells was severely impaired. However, depletion of d2 at a late differentiation stage did not affect osteoclast fusion but did abolish the activity of extracellular acidification and bone resorption of mature osteoclasts. We also showed the association of the two tagged‐proteins d2 and a3 when co‐expressed in mammalian cells with a co‐immunoprecipitation assay. Moreover, glutathione‐S‐transferase (GST) pull‐down assay showed the direct interaction of d2 with the N terminus of Atp6v0a3 (a3), which is the functionally identified osteoclast‐specific component of V‐ATPase. Therefore, our results show the dual function of d2 as a regulator of cell fusion in osteoclast differentiation and as an essential component of the osteoclast‐specific proton pump that mediates extracellular acidification in bone resorption.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Surface pockets of MCM-49 are the main place for the liquid alkylation of benzene with ethylene. The generation of heavy aromatics within the supercage system is the main reason for the deactivation ...of MCM-49 catalyst at the early reaction stage.
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► Liquid alkylation of benzene with ethylene over MCM-49 zeolite was studied. ► Ethylbenzene was mainly produced in the surface pockets. ► Distributions of acidic sites within different pore system were determined. ► Possible reactions within different pores were proposed. ► Effects of alkali-treatment on catalytic performances of MCM-49 were studied.
The properties of three types of pore systems in MCM-49 zeolite have been investigated by precoking to block the supercages and poisoning the surface pockets. Most Lewis acid sites (ca. 73%) are located within the supercages, while 38% of Brönsted acid sites are located in the surface pockets, 28% in the sinusoidal pores and only 34% in the supercages, respectively. Alkylation of benzene with ethylene mainly occurs in the surface pockets, and the contribution from the sinusoidal pores is limited. The generation of heavy aromatics in supercages results in the deactivation of MCM-49 at the early reaction stage. A moderate alkali-treatment process has been demonstrated to enlarge the opening of supercages without affecting the sinusoidal pores, resulting in improved diffusion of big molecules and hence better catalytic performance for liquid alkylation of benzene with ethylene.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Puerarin (PUR) and gastrodin (GAS) are often used in combined way for treating diseases caused by microcirculation disorders. The current study aimed to investigate the absorption and transportation ...mechanism of PUR and GAS and their interaction via Caco-2 monolayer cell model. In this work, the concentration in Caco-2 cell of PUR and GAS was determined by HPLC method. The bidirectional transport of PUR and GAS and the inhibition of drug efflux including verapamil and cyclosporine on the transport of these two components were studied. The mutual influence between PUR and GAS, especially the effect of the latter on the former of the bidirectional transport were also investigated. The transport of 50 μg·mL
PUR in Caco-2 cells has no obvious directionality. While the transport of 100 and 200 μg·mL
PUR presents a strong directionality, and this directionality can be inhibited by verapamil and cyclosporine. When PUR and GAS were used in combination, GAS could increase the absorption of PUR while PUR had no obvious influence on GAS. Therefore, the compatibility of PUR and GAS is reasonable, and GAS can promote the transmembrane transport of PUR, the effect of which is similar to that of verapamil.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
In this work, a model for predicting the leakage rate was developed to investigate the effect of irradiation on the sealing performance of ethylene propylene diene monomer (EPDM) O-rings. The model ...is based on a mesoscopic interfacial gap flow simulation and accurately predicts the sealing performance of irradiated and non-irradiated materials by utilizing the gap height as an indicator in a mechanical simulation of the O-ring under operating conditions. A comparison with vacuum test results indicates that the model is a good predictor of leak initiation. The positive pressure leakage of the O-rings was investigated numerically. The results show the following. The sealing performance of the non-irradiated O-ring is much better than that of the irradiated one. The sealing performance is the worst at 0. 713 MGy and the best at 1.43 MGy, and the seal is maintained at an absorbed dose of 3.55 MGy. A theoretical analysis of the non-monotonic variation using the proposed model shows that the leakage behavior of the O-rings depends not only on the material properties but also on the roughness and prestressing properties. Finally, a method was proposed to classify the sealing performance, using the maximum allowable leakage rate as an indicator.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Propionylation has been identified recently as a new type of protein post-translational modification. Bacterial propionyl-CoA synthetase and human histone H4 are propionylated at specific lysine ...residues that have been known previously to be acetylated. However, other proteins subject to this modification remain to be identified, and the modifying enzymes involved need to be characterized. In this work, we report the discovery of histone H3 propionylation in mammalian cells. Propionylation at H3 lysine Lys23 was detected in the leukemia cell line U937 by mass spectrometry and Western analysis using a specific antibody. In this cell line, the propionylated form of Lys23 accounted for 7%, a level at least 6-fold higher than in other leukemia cell lines (HL-60 and THP-1) or non-leukemia cell lines (HeLa and IMR-90). The propionylation level in U937 cells decreased remarkably during monocytic differentiation, indicating that this modification is dynamically regulated. Moreover, in vitro assays demonstrated that histone acetyltransferase p300 can catalyze H3 Lys23 propionylation, whereas histone deacetylase Sir2 can remove this modification in the presence of NAD+. These results suggest that histone propionylation might be generated by the same set of enzymes as for histone acetylation and that selection of donor molecules (propionyl-CoA versus acetyl-CoA) may determine the difference of modifications. Because like acetyl-CoA, propionyl-CoA is an important intermediate in biosynthesis and energy production, histone H3 Lys23 propionylation may provide a novel epigenetic regulatory mark for cell metabolism.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
TLR7/9 signals are capable of mounting massive interferon (IFN) response in plasmacytoid dendritic cells (pDCs) immediately after viral infection, yet the involvement of epigenetic regulation in this ...process has not been documented. Here, we report that zinc finger CXXC family epigenetic regulator CXXC5 is highly expressed in pDCs, where it plays a crucial role in TLR7/9- and virus-induced IFN response. Notably, genetic ablation of CXXC5 resulted in aberrant methylation of the CpG-containing island (CGI) within the
gene and impaired IRF7 expression in steady-state pDCs. Mechanistically, CXXC5 is responsible for the recruitment of DNA demethylase Tet2 to maintain the hypomethylation of a subset of CGIs, a process coincident with active histone modifications and constitutive transcription of these CGI-containing genes. Consequently, CXXC5-deficient mice had compromised early IFN response and became highly vulnerable to infection by herpes simplex virus and vesicular stomatitis virus. Together, our results identify CXXC5 as a novel epigenetic regulator for pDC-mediated antiviral response.
Decoction is one of the oldest forms of traditional Chinese medicine and it is widely used in clinical practice. However, the quality evaluation and control of traditional decoction is a challenge ...due to the characteristics of complicated constituents, water as solvent, and temporary preparation. ShenFu Prescription Decoction (SFPD) is a classical prescription for preventing and treating many types of cardiovascular disease. In this article, a comprehensive and rapid method for quality evaluation and control of SFPD was developed, via qualitative and quantitative analysis of the major components by integrating ultra-high-performance liquid chromatography equipped with quadrupole time-of-flight mass spectrometry and ultra-fast-performance liquid chromatography equipped with triple quadrupole mass spectrometry. Consequently, a total of 39 constituents were tentatively identified in qualitative analysis, of which 21 compounds were unambiguously confirmed by comparing with reference substances. We determined 13 important constituents within 7 min by multiple reaction monitoring. The validated method was applied for determining five different proportion SFPDs. It was found that different proportions generated great influence on the dissolution of constituents. This may be one of the mechanisms for which different proportions play different synergistic effects. Therefore, the developed method is a fast and useful approach for quality evaluation of SFPD.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
In China, disputes regarding the benefits and drawbacks of land finance have been heated, but the role of land in urban economic growth has received insufficient attention, particularly on a macro ...scale. This research used the Cobb–Douglas production function model to investigate the role of land in urban economic growth. Then, we conducted an empirical test using panel data from 30 provinces from 2000 to 2019, with the goal of revealing the role of land in urban growth and spatio-temporal inequalities in China. Furthermore, to find the spatial steady-state level of land contributions, σ convergence, absolute β convergence, and condition β convergence tests were applied. The results show that: (1) China’s urban economic development was influenced by the combined element of land, capital, and labor; (2) the contribution of land to China’s urban economy experienced a turning point during the “12th Five-Year Plan”; (3) the spatio-temporal convergence of the contribution of land showed convergence in the east but nonconvergence in the central and western regions; and (4) β convergence demonstrated convergence in eastern, central, and western China. Given the complex and turbulent international political and economic context, the Chinese government should think about how to foster continuous energy by supporting land-supply policies that are adapted to local needs.
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•Understanding river contamination requires details of geomorphological functions.•A combined geomorphic and physicochemical survey provides this context.•Different trace elements ...followed distinct geomorphic patterns in a river.•Identifying specific hotspots can inform targeted remediation methods.
River morphology plays a vital role in the transport of substance within them. However, our understanding of how natural and artificial morphologies redistribute different potentially toxic elements in acid mine drainage (AMD)-contaminated rivers remains poor. In this study, we linked morphological river features and physicochemical sediment characteristics to trace the redistribution of various potentially toxic elements and elucidate their implications for remediating rivers prone to AMD pollution. A dense network of sediment/soil samples was collected from different river morphological units, such as channels, dam reservoirs, pools, floodplain sandbars and wetlands in an AMD-impacted river. The analyses showed that the contaminant levels in channel generally decreased downstream from the headwater mine site, however, local fluctuations in certain areas were observed due to the trapping effect of various dams along the river. The As and Pb concentrations were higher at floodplain sandbars, while river channels exhibited higher Cd and Zn contamination. The concentrations and geochemical fractions of As, Cd, Cu, Pb and Zn in sediment/soil cores from sandbar and river channel also varied. Additionally, structural equation modeling analysis indicated that spatial variations in contaminant distributions were directly affected by physicochemical properties (such as the soil/sediment Fe, Zn, and S concentrations, and pH), which are indirectly affected by river morphology. The diverse morphology of the river redistributed AMD-derived contaminants and could be used to identify contamination hotspots. Our analyses suggested that the feasibility and efficiency of previously proposed countermeasures varied for contaminants in different geomorphological units. In river channels, As uptake from sediments by aquatic plants may be less efficient than Cd, Cu, and Zn uptake due to its lower bioavailability. Moreover, vegetation prevented contaminant enriched soil particle erosion more than it aided in the phytoremediation of As- and Pb-contaminated sandbars. Thus the finding of this study provide a theoretical foundation for further studies on the transport and storage of AMD-derived contaminants in similar rivers, along with the development of targeted remediation methods.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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