12 research outputs found

    Influence of External Surface Radiation Properties on Thermal Performance of Walls——Take a typical office building in Chengdu as an example

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    In this paper, taking a typical office building in Chengdu as an example, the coupling relationship between the radiation properties (short-wave absorption coefficient and long-wave emission coefficient) of the external surface materials of the wall and the insulation types and the insulation performance is studied by using software simulation method. The results show that the internal insulation wall is beneficial to reduce the heating load while the external insulation wall is beneficial to reduce the cooling load. And the external surface material's radiative properties hardly affect the wall insulation type choice. Still, in the case of Chengdu office buildings, interior insulated walls are more conducive to year-round building energy efficiency. In summer, the radiation characteristics of the outer surface material will affect the choice of the best heat transfer coefficient (U-value) of the wall. When the short-wave radiation absorption coefficient is small, the wall with good insulation performance will appear anti-energy-saving phenomenon. Therefore, it is recommended that the regions with high cooling loads fully consider the influence of the external surface material's radiation properties on the wall's thermal performance in the design of the thermal performance of the wall

    Effect of Window Openable Area and Shading on Indoor Thermal Comfort and Energy Efficiency in Residential Buildings with Various Operating Modes

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    Solar heat gain and natural ventilation cooling of the indoor environment in buildings are highly influenced by the shading and openable area of windows. In addition to the ambient condition, the Heating, ventilation and air conditioning (HVAC) system’s mode of use can affect the windows’ performance, especially when multiple modes are used in combination (mixed-mode). Although many studies have investigated the mixed-mode application, their conditions for starting/shutting down HVAC equipment and controlling window ventilation are inconsistent with the relevant codes. Here, we propose a mixed-mode operation that resolves the gap between the air conditioning operation temperature and the adaptive comfort upper temperature. It investigates residential buildings’ indoor thermal environment and energy efficiency by combining the effective ventilation opening area ratio (REV) and shading design. Simulation results show that our mixed-mode can reduce the indoor overheating hours by about 50% and the building’s energy consumption by about 50%. We thereby conclude that the openable area of exterior windows in residential buildings in Chongqing should not be less than 10% of the room’s floor axis area where the exterior windows are located. In general, our study expands the existing knowledge of passive energy-saving measures and provides a method for further research on building energy design in hot summer and cold winter regions

    Pancreatic Cancer Cell-Derived Exosomes Promote Lymphangiogenesis by Downregulating ABHD11-AS1 Expression

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    Research on pancreatic cancer microbiomes has attracted attention in recent years. The current view is that enriched microbial communities in pancreatic cancer tissues may affect pancreatic cancer metastasis, including lymph node (LN) metastasis. Similar to carriers of genetic information between cells, such as DNA, mRNA, protein, and non-coding RNA, exosomes are of great importance in early LN metastasis in tumors, including pancreatic cancer. Our previous study showed that the long non-coding RNA ABHD11-AS1 was highly expressed in tissues of patients with pancreatic cancer, and was correlated with patient survival time. However, the role of ABHD11-AS1 in pancreatic cancer LN metastasis has rarely been studied. Hence, in this paper we confirmed that exosomes derived from pancreatic cancer cells could promote lymphangiogenesis in vitro and in vivo, and that the mechanism was related to the downregulation of ABHD11-AS1 expression in lymphatic endothelial cells, and to the enhancement of their ability to proliferate, migrate, and form tubes. These findings preliminarily show a new mechanism by which pancreatic cancer cells regulate peripheral lymphangiogenesis, providing a new therapeutic strategy for inhibiting LN metastasis in pancreatic cancer

    The Deinococcus protease PprI senses DNA damage by directly interacting with single-stranded DNA

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    Abstract Bacteria have evolved various response systems to adapt to environmental stress. A protease-based derepression mechanism in response to DNA damage was characterized in Deinococcus, which is controlled by the specific cleavage of repressor DdrO by metallopeptidase PprI (also called IrrE). Despite the efforts to document the biochemical, physiological, and downstream regulation of PprI-DdrO, the upstream regulatory signal activating this system remains unclear. Here, we show that single-stranded DNA physically interacts with PprI protease, which enhances the PprI-DdrO interactions as well as the DdrO cleavage in a length-dependent manner both in vivo and in vitro. Structures of PprI, in its apo and complexed forms with single-stranded DNA, reveal two DNA-binding interfaces shaping the cleavage site. Moreover, we show that the dynamic monomer-dimer equilibrium of PprI is also important for its cleavage activity. Our data provide evidence that single-stranded DNA could serve as the signal for DNA damage sensing in the metalloprotease/repressor system in bacteria. These results also shed light on the survival and acquired drug resistance of certain bacteria under antimicrobial stress through a SOS-independent pathway

    Dissection of gut microbiota and metabolites reveals the hypolipidemic effect of green mulberry leaf tea / black mulberry leaf tea in mice

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    Mulberry leaf has potential in lipid-lowering. Here, we compared the chemical composition and lipid-lowering effects of different mulberry leaf-derived teas, and investigated their underlying gut microbiome-related mechanisms. The main components of mulberry leaf-derived tea were flavonoids, phenolic acids and alkaloids, with green tea (0.60% polyphenols, 3.35% polysaccharides, 0.20% DNJ) containing higher levels than black tea (0.40% polyphenols, 2.95% polysaccharides, 0.15% DNJ). Accordingly, the lipid-lowering efficacy of green tea was superior to that of black tea in high-fat (HFD)-induced hyperlipidemic mice. Black tea increased 2 genera and 130 metabolites, decreased 6 genera and 90 metabolites, while green tea increased 5 genera and 127 metabolites, decreased 15 genera and 64 metabolites. Correlation analysis showed that the alterations of gut microbiota and metabolic profiles caused by mulberry leaf tea were tightly associated with its lipid-lowering effect. Altogether, this study provided a promising functional food targeting gut microbiota for the management of lipid metabolism
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