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Objective To investigate the relationship between serum bicarbonate and bone metabolism index in stage 5 chronic kidney disease (CKD5) patients not on dialysis treatment, and to explore the relationship between metabolic acidosis and the occurrence of mineral and bone metabolic abnormalities in chronic kidney disease (CKD-MBD) in patients with end stage renal disease (ESRD) and the possible mechanism. Methods Two hundred and fifty-two patients with CKD stage 5 were collected and were grouped according to serum standard bicarbonate (SB) level. SB<22 mmol/L was defined as acidosis group (217 cases), and SB>22 mmol/L was defined as no acid poisoning group (35 cases). The data including SB, serum creatinine (Scr), urea nitrogen (BUN), blood albumin (Alb), blood calcium (Ca), blood phosphorus (P), parathyroid hormone (PTH), blood β2-microglobulin (β2-MG), type I collagen carboxyl end peptide beta special sequence (beta-CTX) and total procollagen type I N-terminal propeptide (TPINP) were collected. The product of calcium and phosphorus (Ca×P) was calculated. The parameters of the two groups were compared, and the correlation analysis was made with SB respectively. Results The indexes of BUN, PTH, P, Ca×P, β2-MG, β-CTX and TPINP in the acidosis group were higher than those in the non-acidosis group, and the blood Ca in the acidosis group was lower than that in the non-acidosis group, but there were no statistical differences in the levels of Scr and Alb between the two groups. The correlation analysis showed that SB was positively correlated with blood Ca, the correlation coefficient was 0.255, and negatively correlated with PTH, Ca×P, β2-MG, β-CTX and TPINP, and the correlation coefficients were -0.869, -0.656, -0.775, -0.615 and -0.720, respectively. There was no significant correlation with blood P. Conclusion Metabolic acidosis is involved in the occurrence of CKD-MBD in undialysable CKD5 patients, and the possible mechanism is that metabolic acidosis induces the dysfunction of osteoblasts and osteoclasts. [ABSTRACT FROM AUTHOR]

Aiming at the application of energy-saving and energy storage materials for buildings, a series of octadecane/intumescent graphite forming phase change materials with different octadecane content were prepared by vacuum adsorption method, and the optimal content of octadecane adsorption and its properties were explored through microscopic morphological observation, leakage performance test, differential scanning calorimetry analysis and cold-thermal cycle stability analysis. Through the analysis, it is concluded that when the adsorption amount of octadecane is 90 wt%, the comprehensive performance of the octadecane/expanded graphite forming phase change material under the adsorption content is the best, and its enthalpy of molten enthalpy and solidification enthalpy are 188 J/g and 186.9 J/g, which has a higher enthalpy values compared with different composite phase change materials at home and abroad. After heating the oven at 50 ℃ for 2 h, there is no obvious phenomenon of octadecane exudation, and the quality loss rate is less than 1%, indicating that it has good anti-leakage performance and structural stability. [ABSTRACT FROM AUTHOR]