Management of resilient urban integrated energy system: State-of-the-art and future directions.

The urban integrated energy system (UIES) is the fundamental infrastructure supporting the operation of resilient cities. The resilience of UIES plays a critical role in effectively responding to extreme events. We provide a comprehensive review on the management of resilient UIES. Firstly, we examine the existing studies on the resilience of UIES through quantitative and qualitative methodologies. Secondly, it points out that the coupling characteristics of UIES have a dual impact on resilience. The definition of UIES resilience can be understood from three perspectives, namely partial resilience versus total resilience, physical resilience versus digital resilience, and current resilience versus future resilience. Thirdly, this review summarizes the strategies for improving the resilience of UIES across three distinct stages, namely before, during, and after extreme events. The resilience of UIES can be enhanced by effective measures to prediction, adaptation, and assessment. Finally, the challenges faced by management of resilient UIES are presented and discussed, in terms of mitigating compound risks, modeling complex systems, addressing data collection and quality issue, and collaborating within multi stakeholders.

Multi-scenario reduction pathways and decoupling analysis of China's sectoral carbon emissions.

To achieve its goal of carbon emissions peak and neutrality, China requires synergistic efforts across all sectors. In this study, three scenarios-baseline, policy, and green low-carbon-were developed to explore the pathways for China's emissions reduction across sectors from 2020 to 2060, and the timing of decoupling economic growth from CO2. The results showed that, under these scenarios, China's carbon emissions peak in 2030, 2026, and 2025, with strong decoupling time, lagged one year behind peak attainment. The agriculture, forestry, livestock, and fishing (AFH) and mining and quarrying (MQ) sectors would be the first to achieve a carbon peak. Under all three scenarios, all of the other sectors-with the exception of electricity, gas, and water production and supply (EGW)-will achieve a carbon peak by 2030. Therefore, policymakers should set carbon peak goals based on sector characteristics and ensure energy security in the process of achieving carbon neutrality.

Effects of choline deficiency and supplementation on lipid droplet accumulation in bovine primary liver cells in vitro.

Rumen-protected choline (RPC) supplementation in the periparturient period has in some instances prevented and alleviated fatty liver disease in dairy cows. Mechanistically, however, it is unclear how choline prevents the accumulation of lipid droplets (LD) in liver cells. In this study, primary liver cells isolated from liver tissue obtained via puncture biopsy from 3 nonpregnant mid-lactation multiparous Holstein cows (∼160 d postpartum) were used. Analyses of LD via oil red O staining, protein abundance via Western blotting, and phospholipid content and composition measured by thin-layer chromatography and HPLC/mass spectrometry were performed in liver cells cultured in choline-deficient medium containing 150 µmol/L linoleic acid for 24 h. In a subsequent experiment, lipophagy was assessed in liver cells cultured with 30, 60, or 90 µmol/L choline-chloride. All data were analyzed statistically using SPSS 20.0 via t-tests or one-way ANOVA. Compared with liver cells cultured in Dulbecco's Modified Eagle Medium alone, choline deficiency increased the average diameter of LD (1.59 vs. 2.10 µm), decreased the proportion of small LD (<2 µm) from 75.3% to 56.6%, and increased the proportion of large LD (>4 µm) from 5.6% to 15.0%. In addition, the speed of LD fusion was enhanced by the absence of choline. Among phospholipid species, the phosphatidylcholine (PC) content of liver cells decreased by 34.5%. Seventeen species of PC (PC [18:2_22:6], PC [15:0_16:1], PC [14:0_20:4], and so on) and 6 species of lysophosphatidylcholine (LPC; LPC [15:0/0:0]), PC (22:2/0:0), LPC (20:2/0:0), and so on] were decreased, while PC (14:1_16:1) and LPC (0:0/20:1) were increased. Choline deficiency increased the triglyceride (TAG) content (0.57 vs. 0.39 µmol/mg) in liver cells and increased the protein abundance of sterol regulatory element binding protein 1, sterol regulatory element binding protein cleavage activation protein, and fatty acid synthase by 23.5%, 17%, and 36.1%, respectively. Upon re-supplementation with choline, the phenotype of LD (TAG content, size, proportion, and phospholipid profile) was reversed, and the ratio of autophagy marker LC3II/LC3I protein was significantly upregulated in a dose-dependent manner. Overall, at least in vitro in mid-lactation cows, these data demonstrated that PC synthesis is necessary for normal LD formation, and both rely on choline availability. According to the limitation of the source of liver cells used, further work should be conducted to ascertain that these effects are applicable to liver cells from postpartum cows, the physiological stage where the use of RPC has been implemented for the prevention and treatment of fatty liver.

Evaluation of Lipid Droplet Size and Fusion in Bovine Hepatic Cells.

Lipid droplets (LDs) are organelles that play an important role in lipid metabolism and neutral lipid storage in cells. They are associated with a variety of metabolic diseases, such as obesity, fatty liver disease, and diabetes. In hepatic cells, the sizes and numbers of LDs are signs of fatty liver disease. Moreover, the oxidative stress reaction, cell autophagy, and apoptosis are often accompanied by changes in the sizes and numbers of LDs. As a result, the dimensions and quantity of LDs are the basis of the current research regarding the mechanism of LD biogenesis. Here, in fatty acid-induced bovine hepatic cells, we describe how to use oil red O to stain LDs and to investigate the sizes and numbers of LDs. The size distribution of LDs is statistically analyzed. The process of small LDs fusing into large LDs is also observed by a live cell imaging system. The current work provides a way to directly observe the size change trend of LDs under different physiological conditions.

Proteomic analysis of milk fat globule membranes from small-sized milk fat globules and their function in promoting lipid droplet fusion in bovine mammary epithelial cells.

In mammary epithelial cells, milk fat is synthesized as lipid droplets and secreted in the form of globules. Milk fat globules (MFGs) are covered by a lipid-protein membrane known as the milk fat globule membrane (MFGM). We randomly divided 12 Holstein cows into control and conjugated linoleic acid (CLA) groups. The control group was fed a basal diet, while the CLA group was fed the basal diet + CLA (15 g per kg DM) for 10 days. Cow performance, milk composition, and MFG size were measured daily. On day 10, we extracted MFGM proteins (n = 3) and identified them via quantitative proteomic analysis. We investigated the effects of the MFGM proteins from control and CLA-treated milk on the lipid droplet formation in MAC-T cells. Compared with the control group, the CLA group had reduced milk fat content (3.39 g/100 mL vs. 2.45 g/100 mL) and MFG size parameters (D[4,3] of 3.85 µm vs. 3.37 µm; D[3,2] of 3.24 µm vs. 2.83 µm). The specific surface area (SSA) increased in the CLA group. A total of 361 differentially expressed proteins were identified in the CLA group by iTRAQ quantitative proteomic analysis. Among these proteins, 100 were upregulated and 251 were downregulated (p < 0.05). In MAC-T cells, CLA-MFGM proteins increased the diameter of the lipid droplets to 1.32 µm. CLA-MFGM proteins decreased the proportion of the small lipid droplets (15.33% vs. 47.78%) and increased the proportion of the large lipid droplets (25.04% vs. 11.65%). CLA-MFGM proteins promoted lipid droplet fusion. Therefore, MFGM proteins play an important role in the regulation of the lipid droplet size.

Spatial and temporal evolution characteristics and spillover effects of China's regional carbon emissions.

China's carbon emissions account for approximately a quarter of the world's total greenhouse gas emissions. In 2020, China's fossil fuels accounted for approximately 85% of the primary energy demand, with coal alone accounting for 60%. Considering the severe global warming situation, it is necessary to reveal the spatial and temporal differences and analyze the spillover effects of carbon emissions between regions. In this study, a positive and significant spatial correlation between regional carbon emissions in China was found using an exploratory spatial data analysis. The spatial Durbin model was then utilized to explore the direct and spillover effects of factors that included economic growth, the energy intensity, and the level of technological innovation on regional carbon emissions. Whether a direct effect or a spillover effect, economic growth and improvements in the regional levels of technological innovation had significant inhibitory effects on carbon emissions both in the long term and in the short term. Specifically, an increase of 1% in the level of technological innovation led to a reduction of approximately 0.17% in the region's carbon emissions. However, a growth in the energy intensity will increase carbon emissions. In addition, an increase in the technological input intensity will lead to an increase in carbon emissions in local regions. However, an increase in neighboring regions will restrain carbon emissions in a local region. Based on these findings, it is recommended that the government accelerate regional innovation synergies and increase investment in clean energy technologies.

Size, number and phospholipid composition of milk fat globules are affected by dietary conjugated linoleic acid.

Milk fat globules (MFGs) surround the triacylglycerol core that composes milk fat. The aim of this study is to induce milk fat depression via dietary conjugated linoleic acid (CLA) supplementation to study MFG size parameters, number and glycerophospholipid composition. Eighteen Holstein dairy cows (136 ± 28 days in milk, 571 ± 37.9 kg body weight, 27.6 ± 2.1 kg milk/day) were selected and randomly assigned to a control or CLA group for a 14-day period. Cows were fed a basal diet (control, n = 8) or the control plus 400 g/day CLA (C18:2 cis-9, trans-11 38.1% and C18:2 trans-10, cis-12 36.8%) (n = 10) for 7 days after which the CLA group was switched to the basal diet for another 7 days along with the control group. Cow performance, milk composition, MFG size and numbers were measured daily. On the seventh day after the start of the experiment, milk samples were identified and the quantification of glycerophospholipid compounds, and RNA were isolated from milk fat samples for a real-time polymerase chain reaction. Compared with control, at Day 7 from the start of feeding, supplemental CLA did not affect milk production (28.09 vs. 28.50 kg/day), dry matter intake (14.9 vs. 15.4 kg/day), or milk protein (3.55/100 vs. 3.70 g/100 ml) and lactose contents (5.11/100 vs. 5.17 g/100 ml). However, although the specific surface area of MFG (2138 vs. 1815 m²/kg) was greater, CLA reduced milk fat content (1.95/100 vs 3.64 g/100 ml on Day 7) and particle size parameters of MFG. The number of MFG gradually decreased until Day 7 of feeding, and then increased by Day 14 (2.96 × 109 on Day 1, 1.63 × 109 on Day 7 and 2.28 × 109 on Day 14) in the CLA group. Compared with control, glycerophospholipid analysis revealed that concentrations of phosphatidylcholine (PC) (e.g., PC [16:0/18:1] 20322 vs. 29793 nmol/L), lysophosphatidylethanolamine (LPE) (e.g., LPE [18:1] 956 vs. 4610 nmol/L) and phosphatidylethanolamine (PE) (e.g., PE [16:0/18:1] 7000 vs. 9769 nmol/L) in milk lipids decreased during CLA feeding. In contrast, concentrations of phosphatidylinositol (PI) (e.g., PI [18:0/18:1] 4052 vs. 1799 nmol/L) and phosphatidylserine (PS) (e.g., PS [18:1/18:2] 9500 vs. 6843 nmol/L) increased. The messenger RNA abundance of fatty acid synthase, diacylglycerol O-acyltransferase 1, glycerol-3-phosphate acyltransferase 4 and phosphate cytidylyltransferase 1, choline, alpha (PCYT1A) were downregulated in the CLA group, confirming published data demonstrating a negative effect of CLA on lipogenesis in the mammary gland. Overall, these results provided evidence for the important role of lipogenic gene expression in the regulation of MFG size, number and glycerophospholipid composition.

Milk fat globule membrane proteins are involved in controlling the size of milk fat globules during conjugated linoleic acid-induced milk fat depression.

Milk fat globule membrane (MFGM) proteins surround the triacylglycerol core comprising milk fat globules (MFG). We previously detected a decrease in the size of fat globules during conjugated linoleic acid (CLA)-induced milk fat depression (MFD), and other studies have reported that some MFGM proteins play a central role in regulating mammary cellular lipid droplet size. However, little is known about the relationship between MFD, MFG size, and MFGM proteins in bovine milk. The aim of this study was to investigate the profile of MFGM proteins during MFD induced by CLA. Sixteen mid-lactating Holstein cows (145 ± 24 d in milk) with similar body condition and parity were divided into control and CLA groups over a 10-d period. Cows were fed a basal diet (control, n = 8) or control plus 15 g/kg of dry matter (DM) CLA (n = 8) to induce MFD. Cow performance, milk composition, and MFG size were measured daily. On d 10, MFGM proteins were extracted and identified by quantitative proteomic analysis, and western blotting was used to verify a subset of the identified MFGM proteins. Compared with controls, supplemental CLA did not affect milk production, DM intake, or milk protein and lactose contents. However, CLA reduced milk fat content (3.73 g/100 mL vs. 2.47 g/100 mL) and the size parameters volume-related diameter D[4,3] (3.72 µm vs. 3.35 µm) and surface area-related diameter D[3,2] (3.13 µm vs. 2.80 µm), but increased specific surface area of MFG (1,905 m2/kg vs. 2,188 m2/kg). In total, 177 differentially expressed proteins were detected in milk from cows with CLA-induced MFD, 60 of which were upregulated and 117 downregulated. Correlation analysis showed that MFG size was negatively correlated with various proteins, including XDH and FABP3, and positively correlated with MFG-E8, RAB19, and APOA1. The results provide evidence for an important role of MFGM proteins in regulating MFG diameter, and they facilitate a mechanistic understanding of diet-induced MFD.

Novel Slide-Ring Material/Natural Rubber Composites with High Damping Property.

A novel class of polymers called "slide-ring" (SR) materials with slideable junctions were used for high damping composites for the first time. The SR acts as the high damping phase dispersed in the natural rubber (NR) matrix, and epoxidized natural rubber (ENR) acts as the compatibilizer. The morphological, structural, and mechanical properties of the composites were investigated by atomic force microscope (AFM), transmission electron microscope (TEM), dynamic mechanical thermal analyzer (DMTA), rubber processing analyzer (RPA), and tensile tester. AFM and TEM results showed that the SR phase was uniformly dispersed in the composites, in a small size that is a function of ENR. DMTA and RPA results showed that the damping factor of the composites is much higher than that of NR, especially at room temperatures. Stretch hysteresis was used to study the energy dissipation of the composites at large strains. The results showed that SR and ENR can significantly improve the dissipation efficiency at strains lower than 200% strain. Wide-angle X-ray diffraction was used to study the strain-induced crystallization of the composites. The results indicated that the impact of the SR on the crystallization of NR is mitigated by the insulating effect of ENR.