Institutional Repository of Institute of Process Engineering, CAS (IPE-IR）
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Quantifying spatiotemporal dynamics of urban building and material metabolism by combining a random forest model and GIS-based material flow analysis
No full textUnderstanding building metabolism is critical for guiding urban resource management and addressing challenges in urban sustainable development. Key attributes of buildings, including geolocation, footprint, height, and vintage, are crucial to characterizing spatiotemporal patterns of building metabolism. However, these attributes are usually challenging to obtain broadly and automatically, which obscures a comprehensive understanding and accurate assessment of urban metabolism. Moreover, the lack of a finer spatial pattern of these attributes shadows a spatially explicit characterization of material stock and flow in cities. In this study, we took Shenzhen-whose urbanization over the past three decades has been unprecedented in China and even around the world- has been taken as an example to develop a city-level building dataset based on a random-forest model and quantify the spatiotemporal patterns of material metabolism at relatively high spatial resolution (in 500 m x 500 m grids) by combing material flow analysis (MFA) with geographic information system (GIS). The results show that Shenzhen grew from a small town with 281.02 x 10(6) m(3) of buildings in the 1990s to a mega-city with 3585.5 x 10(6) m(3) of buildings in 2018 and expanded both outward and upward from downtown to suburban areas. The urban "weight " (material stock) increased from 92.69 Mt in the 1990s to 1667.8 Mt in 2018 and tended to be saturated, with an average growth rate of 9.5% per year. Spatially, the south-central areas were the largest container of material stocks and generated the most demolition waste. The spatially explicit maps of building three-dimensional (3-D) form and vintage provide detailed information for architectural conservation and could support the decision-making for urban renewal planning. The spatiotemporal patterns of in-use material stocks and potential generation of construction and demolition waste (CDW) provide a benchmark of environmental risk assessment and potential secondary resources to reduce "original " material consumption, which could help alter urban renewal to an environmental-friendly and sustainable trajectory
A synergistic therapy strategy for hypoxic solid tumor therapy
No full textPhotodynamic therapy (PDT) has been considered an effective treatment for various types of cancers. However, hypoxic microenvironment within the solid tumor is averse to oxygen-involved PDT, resulting in low therapeutic efficacy. This Preview highlights a recent study regarding a synergistic therapy that combines PDT and chemotherapy, in which hypoxic solid tumor diagnosis imaging and therapy can be achieved
A synergistic therapy strategy for hypoxic solid tumor therapy
No full textPhotodynamic therapy (PDT) has been considered an effective treatment for various types of cancers. However, hypoxic microenvironment within the solid tumor is averse to oxygen-involved PDT, resulting in low therapeutic efficacy. This Preview highlights a recent study regarding a synergistic therapy that combines PDT and chemotherapy, in which hypoxic solid tumor diagnosis imaging and therapy can be achieved
A 3D bioprinted decellularized extracellular matrix/gelatin/quaternized chitosan scaffold assembling with poly(ionic liquid)s for skin tissue engineering
No full textCurrently, a suitable bioink for 3D bioprinting and capable of mimicking the microenvironment of native skin and preventing bacterial infection remains a major challenge in skin tissue engineering. In this study, we pre-pared a tissue-specific extracellular matrix-based bioink, and dECM/Gel/QCS (dGQ) 3D scaffold assembling with poly(ionic liquid)s (PILs) (dGQP) was obtained by an extrusion 3D bioprinting technology and dynamic hydrogen bonding method. The morphologies, mechanical properties, porosity, hydrophilicity, biodegradation, hemostatic effect, antibacterial ability, and biocompatibility of the hybrid scaffolds were characterized and evaluated. Re-sults showed that the rapid release (2 h) of PILs on the dGQP scaffold can quickly kill gram-negative (E. coli) and gram-positive (S. aureus) bacteria with almost 100 % antibacterial activity and maintained a stable sterile environment for a long time (7 d), which was superior to the dGQ scaffold. The hemostasis and hemolysis test showed that the dGQP scaffold had a good hemostatic effect and excellent hemocompatibility. In vitro cyto-compatibility studies showed that although the cell growth on dGQP scaffold was slow in the early stage, the cells proliferated rapidly since day 4 and had high ECM secretion at day 7. Overall, this advanced dGQP scaffold has a considerable potential to be applied in skin tissue engineering
Identification and Characterization of Fibronectin-Binding Peptides in Gelatin
No full textCollagen and fibronectin (FN) are important components in the extracellular matrix (ECM). Collagen-FN binding belongs to protein-protein interaction and plays a key role in regulating cell behaviors. In this study, FN-binding peptides were isolated from gelatin (degraded collagen) using affinity chromatography, and the amino acid sequences were determined using HPLC-MS. The results indicated that all FN-binding peptides contained GPAG or GPPG. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and dual-polarization interferometry (DPI) were used to analyze the effects of hydroxylation polypeptide on FN binding activity. DPI analysis indicated that peptides with molecular weight (MW) between 2 kDa and 30 kDa showed higher FN-binding activity, indicating MW range played an important role in the interaction between FN and peptides. Finally, two peptides with similar sequences except for hydroxylation of prolines were synthesized. The FN-binding properties of the synthesized peptides were determined by MALDI-TOF MS. For peptide, GAPGADGP*AGAPGTP*GPQGIAGQR, hydroxylation of P8 and P15 is necessary for FN-binding. For peptide, GPPGPMGPPGLAGPPGESGR, the FN-binding process is independent of proline hydroxylation. Thus, FN-binding properties are proline-hydroxylation dependent
Sulfuric acid leaching of ball-milling activated FePO4 residue after lithium extraction from spent lithium iron phosphate cathode powder
No full textA mechanical-chemical process is proposed to recover the iron phosphate residue(IPR)of spent lithium iron phosphate(LFP)after lithium extraction. In this process, the IPR was pretreated by ball-milling and leached with the sulfuric acid solution. The results showed that, under the optimized ball-milling conditions (a mass ratio of the stainless-steel-ball to material to water of 2:1:2.5, a milling time of 20 min), the maximum particle size of IPR decreased from 34.265 um to 13.102 um, the specific surface increased from 11.41 m2/g to 13.74 m2/g, and the cell volume distortion rate could reach 0.331 %. Under the optimized leaching conditions (a temperature of 333 K, a concentrated acid-to-material ratio of 0.46 mL/g, a liquid-to-solid ratio of 5:1 mL/g, and a stirring speed of 600 rpm), the leaching efficiency of iron phosphate could reach 98 %. The kinetic study indicated that the leaching was controlled by diffusion and chemical reaction with the apparent activation energy of 29 kJ/mol. The dissolution-precipitation phase transition of IPR was also found at high temperatures. This study illustrates that such a mechanical-chemical process is an effective way to improve the leaching efficiency of IPR with a lower sulfuric acid dosage, which has great potential in industrial applications
