Objective To investigate the relationship between biological aging and the rate of cognitive decline in middle-aged and elderly populations.Methods Longitudinal tracking data of cognitive function were obtained from the China Health and Retirement Longitudinal Study(CHARLS).We employed the Klemera and Doubal method(KDM)to estimate biological age(BA),and calculate the biological aging index(BAI)and biological aging type(BAT).A multivariate linear regression model was employed to analyze the relationships between baseline BAI,BAT,and cognitive function scores.Based on the baseline analysis,a mixed-effects model was used to examine the longitudinal associations between baseline BAI,BAT,and cognitive function during follow-up.Results A total of 5 897 participants were included in the study.BAI was found to be negatively associated with baseline cognitive function scores,with the partial regression coefficient(β)(95％CI)being-0.185(—0.231,—0.139)(P＜0.001).Compared with the lagged aging group,the premature aging group had lower cognitive function scores(β[95％CI]:—0.741[—0.966,—0.516]).For age and sex,for each additional year of baseline BAI,cognitive function scores declined by an average of 0.012(95％CI:—0.019,—0.005)points per year after adjusting for age and sex,and declined by 0.011(95％CI:—0.018,—0.004)points per year after adjusting for other covariates.Compared with participants with lagged aging,those with premature aging experienced,on average,an additional decline of 0.042(95％CI:—0.075,0.009)points per year in cognitive function scores after adjusting for age and sex alone,and by 0.039(95％CI:—0.072,—0.007)points per year after adjusting for other covariates.Conclusion Biological aging affects the rate of cognitive decline in middle-aged and elderly populations.A higher BAI is associated with a faster decline in cognitive function.Compared with those with lagged aging,individuals with premature aging exhibit a more rapid rate of cognitive decline.

Objective:To study the trinucleotide repeats of GCN (GCA, GCT, GCC, GCG) encoding Alanine in exon 3 of the PHOX2B gene among healthy individuals from southwest China and two patients with Congenital central hypoventilation syndrome (CCHS). Methods:The number and sequence of the GCN repeats of the PHOX2B gene were analyzed by capillary electrophoresis, Sanger sequencing and cloning sequencing of 518 healthy individuals and two newborns with CCHS, respectively. Results:Among the 1036 alleles of the 518 healthy individuals, five alleles were identified, including (GCN) 7, (GCN) 13, (GCN) 14, (GCN) 15 and (GCN) 20. The frequency of the (GCN) 20 allele was the highest (94.79%). And five genotypes were identified, which included (GCN) 7/(GCN) 20, (GCN) 13/(GCN) 20, (GCN) 14/(GCN) 20, (GCN) 15/(GCN) 20, (GCN) 20/(GCN) 20. The homozygous genotypes were all (GCN) 20/(GCN) 20, and the carrier rate was 89.58%. Four GCN sequences of the (GCN) 20 homozygous genotypes were identified among the 464 healthy individuals. The GCN repeat numbers in the exon 3 of the PHOX2B gene showed no significant difference between the expected and observed values, and had fulfilled the, Hardy-Weinberg equilibrium. The genotypes of the two CCHS patients were (GCN) 20/(GCN) 25 and (GCN) 20/(GCN) 30, respectively. Conclusion:It is important to determine the GCN repeats and genotypic data of the exon 3 of the PHOX2B gene among the healthy individuals. The number of GCN repeats in 518 healthy individuals was all below 20. The selection of appropriate methods can accurately detect the polyalanine repeat mutations (PARMs) of the PHOX2B gene, which is conducive to the early diagnosis, intervention and treatment of CCHS.

Objective To explore the changes of residual lipoprotein-cholesterol (RLP-C) after three meals in coronary heart disease group and control group, to explore the best time point for detecting post-prandial RLP-C levels. Methods Thirty-one patients andcontrols were recruited and divided into coronary heart disease group and control group. Vein blood samples were collected at 4 hours of fasting and three meals, and serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides (TG) concentrations were measured. Serum RLP-C levels was calculated according to the equation. Results There were no significant differences in serum fasting TC, TG, LDL-C, non-HDL-C and RLP-C levels between CHD patients and controls (P＞ 0. 05). The CHD patients had lower HDL-C concentrations than controls (P ＜ 0. 05). Postprandial serum TG and RLP-C levels increased significantly in CHD patients after each meal (P ＜ 0. 01), and reached the peak at 4 hours after dinner. The CHD patients had higher postprandial serum RLP-C levels after lunch and dinner, and higher serum TG level after lunch than the controls (P ＜ 0. 05). Conclusion There was no significant difference in the concentration of fasting serum RLP-C between the two groups. However, its concentration changed more significantly at 4 hours after lunch and dinner compared to that of fasting. Therefore, the RLP-C level measured at 4 hours after lunch and dinner may be more practical in clinic.

Objective To explore the changes of residual lipoprotein-cholesterol (RLP-C) after three meals in coronary heart disease group and control group, to explore the best time point for detecting post-prandial RLP-C levels. Methods Thirty-one patients andcontrols were recruited and divided into coronary heart disease group and control group. Vein blood samples were collected at 4 hours of fasting and three meals, and serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides (TG) concentrations were measured. Serum RLP-C levels was calculated according to the equation. Results There were no significant differences in serum fasting TC, TG, LDL-C, non-HDL-C and RLP-C levels between CHD patients and controls (P＞ 0. 05). The CHD patients had lower HDL-C concentrations than controls (P ＜ 0. 05). Postprandial serum TG and RLP-C levels increased significantly in CHD patients after each meal (P ＜ 0. 01), and reached the peak at 4 hours after dinner. The CHD patients had higher postprandial serum RLP-C levels after lunch and dinner, and higher serum TG level after lunch than the controls (P ＜ 0. 05). Conclusion There was no significant difference in the concentration of fasting serum RLP-C between the two groups. However, its concentration changed more significantly at 4 hours after lunch and dinner compared to that of fasting. Therefore, the RLP-C level measured at 4 hours after lunch and dinner may be more practical in clinic.

Objective To explore the best multiplicities of infection (MOI),the expression of the target gene and in vitro MR imaging of adenovirus vector-mediated transferrin receptor (TFRC) reporter gene transfection of human colorectal cancer Lovo cells.Methods Lovo cells were transfected with recombinant adenovirus (Ad-TFRC) at 5,10,50,100 MOI to determine the best MOI,and quantitative real-time PCR was performed to detect the eDNA of TFRC.The transfected cells were incubated in the culture medium including Tf-USPIO of various concentrations,and were observed by Prussian blue staining,then the cell viability was evaluated via Trypan blue staining.The labeled cells were scanned with 7.0T MR T2W,T2 map,T2* map sequences,and the signal intensities were analyzed.Results Ad-TFRC were successfully transfected into Lovo cells.The best MOI was 50,and the efficiency of infection was more than 90％.The relative expression amount of TFRC in transfected cells was higher than that in control Lovo cells by real-time quantitive PCR (P＜ 0.01).Prussian blue staining showed numerous blue iron particles in transfected cells when the best labeling concentration was 1.5 μg/ml.Trypan blue staining results of transfected Lovo cells and control Lovo cells was (93.80± 1.60)％ and (95.10±2.30) ％,respectively (P＞0.05).MR imaging in vitro showed that compared with control Lovo cells,the signal intensity decreased on T2WI,T2 map and T2* map sequences in transfected Lovo cells (P＜0.05).Conclusion TFRC reporter gene can be efficiently mediated by adenovirus for expression in Lovo cells.After magnetization labeling,7.0T MR imaging of Lovo cells can be successfully achieved in vitro.

Objective To study the biosynthesis of the second metabolites in Aquilaria sinensis.Methods Chromones of agarwood were elicited by tissue culture and the inducer contents were determined by HPLC.Results 2-(2-Phenylethyl) chromones could be elicited in excised lateral roots suspension culture of A.sinensis.Conclusion Fungal extracts of Menanotus flavolives could induce the production of characteristic components of agarwood in A.sinensis.