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Context The components of metabolic syndrome (MetS) are interrelated and associated with renal complications in patients with type 2 diabetes (T2D). Objective We aimed to reveal prevalent metabolic profiles in patients with T2D and identify which metabolic profiles were risk markers for renal progression. Methods A total of 3556 participants with T2D from a hospital (derivation cohort) and 931 participants with T2D from a community survey (external validation cohort) were included. The primary outcome was the onset of diabetic kidney disease (DKD), and secondary outcomes included estimated glomerular filtration rate (eGFR) decline, macroalbuminuria, and end-stage renal disease (ESRD). In the derivation cohort, clusters were identified using the 5 components of MetS, and their relationships with the outcomes were assessed. To validate the findings, participants in the validation cohort were assigned to clusters. Multivariate odds ratios (ORs) of the primary outcome were evaluated in both cohorts, adjusted for multiple covariates at baseline. Results In the derivation cohort, 6 clusters were identified as metabolic profiles. Compared with cluster 1, cluster 3 (severe hyperglycemia) had increased risks of DKD (hazard ratio [HR] [95% CI]: 1.72 [1.39-2.12]), macroalbuminuria (2.74 [1.84-4.08]), ESRD (4.31 [1.16-15.99]), and eGFR decline [ P <.001]; cluster 4 (moderate dyslipidemia) had increased risks of DKD (1.97 [1.53-2.54]) and macroalbuminuria (2.62 [1.61-4.25]). In the validation cohort, clusters 3 and 4 were replicated to have significantly increased risks of DKD (adjusted ORs: 1.24 [1.07-1.44] and 1.39 [1.03-1.87]). Conclusion We identified 6 prevalent metabolic profiles in patients with T2D. Severe hyperglycemia and moderate dyslipidemia were validated as significant risk markers for DKD. [ABSTRACT FROM AUTHOR]

Polyurethane rigid foam is a widely used insulation material, and the behavior characteristics and heat absorption performance of the blowing agent used in the foaming process are key factors that affect the molding performance of this material. In this work, the behavior characteristics and heat absorption of the polyurethane physical blowing agent in the foaming process were studied; this is something which has not been comprehensively studied before. This study investigated the behavior characteristics of polyurethane physical blowing agents in the same formulation system, including the efficiency, dissolution, and loss rates of the physical blowing agents during the polyurethane foaming process. The research findings indicate that both the physical blowing agent mass efficiency rate and mass dissolution rate are influenced by the vaporization and condensation process of physical blowing agent. For the same type of physical blowing agent, the amount of heat absorbed per unit mass decreases gradually as the quantity of physical blowing agent increases. The relationship between the two shows a pattern of initial rapid decrease followed by a slower decrease. Under the same physical blowing agent content, the higher the heat absorbed per unit mass of physical blowing agent, the lower the internal temperature of the foam when the foam stops expanding. The heat absorbed per unit mass of the physical blowing agents is a key factor affecting the internal temperature of the foam when it stops expanding. From the perspective of heat control of the polyurethane reaction system, the effects of physical blowing agents on the foam quality were ranked in order from good to poor as follows: HFC-245fa, HFC-365mfc, HFCO-1233zd(E), HFO-1336mzzZ, and HCFC-141b. [ABSTRACT FROM AUTHOR]

This work developed a novel method for measuring the effective rate of a PBA (physical blowing agent) and solved the problem that the effective rate of a PBA could not be directly measured or calculated in previous studies. The results show that the effectiveness of different PBAs under the same experimental conditions varied widely, from approximately 50% to almost 90%. In this study, the overall average effective rates of the PBAs HFC-245fa, HFO-1336mzzZ, HFC-365mfc, HFCO-1233zd(E), and HCFC-141b are in descending order. In all experimental groups, the relationship between the effective rate of the PBA, r e P B A , and the initial mass ratio of the PBA to other blending materials in the polyurethane rigid foam, w , demonstrated a trend of first decreasing and then gradually stabilizing or slightly increasing. This trend is caused by the interaction of PBA molecules among themselves and with other component molecules in the foamed material and the temperature of the foaming system. In general, the influence of system temperature dominated when w was less than 9.05 wt%, and the interaction of PBA molecules among themselves and with other component molecules in the foamed material dominated when w was greater than 9.05 wt%. The effective rate of the PBA is also related to the states of gasification and condensation when they reach equilibrium. The properties of the PBA itself determine the overall efficiency, while the balance between the gasification and condensation processes of the PBA further leads to a regular change in efficiency with respect to w around the overall average level. [ABSTRACT FROM AUTHOR]

Adsorption is a potential technology that is expected to meet NOx ultra-low emission standards and achieve the recovery of NO2. In this study, the adsorption/desorption behavior of NOx with competitive gases (e.g., H2O(g) and CO2) was studied on MFI zeolites with different Si/Al ratios and under different relative humidity (0~90% RH). Sample characterization of self-synthesizing zeolites was conducted by means of X-ray diffraction, Ar adsorption-desorption, and field emission scanning electron microscopy. The results showed that low-silica HZSM-5(35) showed the highest NOx adsorption capacity of 297.8 μmol/g (RH = 0) and 35.4 μmol/g (RH = 90%) compared to that of other adsorbents, and the efficiency loss factor of NOx adsorption capacity at 90%RH ranged from 85.3% to 88.1%. A water-resistance strategy was proposed for NOx multicomponent competitive adsorption combined with dynamic breakthrough tests and static water vapor adsorption. The presence of 14% O2 and lower adsorption temperature (25 °C) favored NOx adsorption, while higher CO2 concentrations (~10.5%) had less effect. The roll-up factor (η) was positively correlated with lower Si/Al ratios and higher H2O(g) concentrations. Unlike Silicalite-1, HZSM-5(35) exhibited an acceptable industrial desorption temperature window of NO2 (255~265 °C). This paper aims to provide a theoretical guideline for the rational selection of NOx adsorbents for practical applications. [ABSTRACT FROM AUTHOR]

A small scale (~270 Nm3·h−1) vacuum pressure swing adsorption (VPSA) air separation system was established in Qinghai Province (in China) with an altitude of 3800 m, which was used to supply oxygen for relieving the hypoxia. The effects of adsorption and desorption time, purge and pressure equalization step and feed temperature on the performance of the process were investigated by performing experiments under plateau special conditions. Results showed that pressure equalization and intermittent purge steps could effectively improve the performance of the VPSA process. The system could produce 270 Nm3·h−1 of 90% O2 with 62.6% oxygen recovery from compressed air. The maximum productivity and minimum energy consumption with pressure ratio of 160:42 for ~90% O2 were 121.7 L·h−1·kg−1 and 0.55 kWh·Nm−3, respectively. [ABSTRACT FROM AUTHOR]

Computational fluid dynamics (CFD) was adopted to investigate the influence of the three-section opening strategy in the Z type centripetal radial flow reactor on the uniformity of the gas flow, which aimed to optimize the opening rate of the reactor. The simulation results showed that as the pore-opening ratio of are 10%, 16% and 29% for three sections from top to bottom of the central channel, the opening rate of the circular channel perforated plate is 10–12%, 21–25% and 30–40% from top to bottom, respectively; the uniformity of the reactor was then achieved. Through the simulation results, it was also found that the change in the opening rate at the center pipe perforated plate had a greater contribution to the gas flow mal-distribution inside the reactor. The contribution of the change in the opening rate of the annular channel perforated plate to the uniformity of the gas flow inside the reactor was smaller than that of the center pipe. Annular channel width should not be smaller, such that gas flow malfunction inside the reactor could be avoided, although high-speed velocity cases were encountered. [ABSTRACT FROM AUTHOR]