Objective To investigate the results of ambulatory electrocardiographic(ECG)monitoring in a community-based homebound elderly population and to explore the applicability of wearable long-range ambulatory ECG monitor for them.Methods Elderly volunteers were recruited in Shuangbei Community,Shapingba District,Chongqing,from November 2021 to June 2023.A single-lead wearable ambulatory ECG recorder was applied to them to obtain ECG for 7 consecutive days.The adverse reactions,acceptability,monitoring duration,and arrhythmia detection rate during the wearing were described and recorded.Serious arrhythmic events included frequent atrial premature,atrial flutter,atrial fibrillation(AF),frequent ventricular premature,and RR intervals ≥5 s.Results There were 416 individuals enrolled,with a mean age of 71.2±6.6 years,and a male percentage of 36.1％(150 men).Finally,384(92.3％)participants completed the wearing of the ECG monitor for 7 d,with an average time of 159.2±29.4 h.There were 179 participants(48.5％)reporting no discomfort during wearing,and 175 ones(47.4％)feeling itchy at the wearing site.The monitoring results showed that the common arrhythmias were atrial premature contractions(97.1％),premature ventricular contractions(93.3％),atrial tachycardia(84.6％),bradycardia(46.6％),frequent atrial premature contractions(15.1％),ventricular tachycardia(13.2％),and long RR interval(11.8％).Among them,29.1％of the participants experienced serious arrhythmic events,and the detection rate of certain serious arrhythmic events was comparatively higher in the individuals≥70 years of age and those with history of previous cardiac disease.Conclusion The detection rate of common arrhythmias is quite high in the community-based homebound elderly population.A 7-day long-range ambulatory ECG monitoring may be appropriate.

Objective To analyze and construct systolic blood pressure(SBP)fluctuation trajectory in a community population with hypertension and to analyze the factors influencing different trajectories.Methods This is a community-based retrospective cohort study.A latent class trajectory model was used to identify and construct longitudinal trajectories of blood pressure change.Multinomial logistic regression analysis was performed to identify the associated factors of blood pressure trajectories by adjusting for different confounders.Potential confounding factors were identified using a directed acyclic graph based on a priori knowledge.Results A total of 793 patients with hypertension were enrolled in the analysis.They were divided into 3 groups by LCTM-fitted systolic blood pressure trajectories,namely stable low-level group(n=561,70.74％),declining group(n=170,21.44％)and rising group(n=62,7.82％).Significant differences were observed among the 3 trajectories groups in terms of age,frequency of exercise,ways of follow-up,salt intake,compliance behavior,and referral(P＜0.05).Compared to the stable low-level group and adjusting for corresponding confounding factors,the male patients and the patients with"outpatient follow-up"were more likely to be classified into"declining group",with OR and 95％CI of 1.436(1.016～2.030)and 1.702(1.202～2.410),respectively.The participants aged ≥ 65 years,who did not exercise or occasionally exercised,and had moderate and severe salt intake,were more likely to be classified into the"rising group"(OR=1.949,2.284,2.433,4.540,95％CI:1.145～3.317,1.305～3.998,1.272～4.654,1.291～15.963).Conclusion SBP trajectories in community-dwelling hypertensive population can be divided into stable low-level,declining and rising groups.Gender,age,salt intake,exercise frequency,and follow-up methods may be influencing factors for SBP blood pressure trajectory.

【Objective】 To research the genetic polymorphism of HPA 1-6/10/15/21 in platelet donors in Zhongshan area, and establish a gene bank of platelet donors with HPA locus. 【Methods】 The HPA 1-6/10/15/21 system genotyping was performed by Real time fluorescent PCR combined with TaqMan probe technology on 192 platelet donors in Zhongshan area, and the genotype frequency and gene frequency were calculated. 【Results】 Only HPA-aa genotype was found within HPA-4/10, and no allele HPA-b had been detected. The majority of HPA-1, 2, 5, 6 and 21 genotypes were aa. HPA-3 and HPA-15 showed high heterozygosity, with genotype frequency of 0.307 3, 0.494 8 and 0.197 9 for HPA- 3aa, HPA-3ab and HPA-3bb, while 0.270 8, 0.505 2 and, 0.224 0 for HPA -15aa, HPA-15ab and HPA-15bb, respectively. 【Conclusion】 The distribution characteristics of HPA 1-6 /10/15/21 of platelet donors in Zhongshan shows regional differences compared with similar researches from other regions. The establishment of HPA gene bank is helpful to avoid alloimmunization caused by incompatible platelet transfusion.

OBJECTIVE: To study the influence of maternal sex chromosomal abnormalities on the prediction of fetal sex chromosome abnormalities (SCAs) by non-invasive prenatal testing (NIPT). METHODS: Thirty-six pregnant women with a prediction for fetal SCAs by NIPT were verified as false positive after prenatal diagnosis using amniotic fluid samples. With informed consent, these women were subjected to chromosomal karyotyping or copy number variations (CNVs) analysis through high-throughput sequencing. RESULTS: Sex chromosomal abnormalities were found in 8 women, which yielded an abnormal rate of 22.22% (8/36). Among these, 3 had sex chromosome aneuploidies (47, XXX), 4 had sex chromosome mosaicisms, and 1 carried structural chromosomal abnormalities. Reanalysis of the results of NIPT were consistent with the maternal CNVs by large. With the ratio of cffDNA (ChrX)/cffDNA was more than 2, 6 of the eight women were found to harbor sex chromosome abnormalities, and the fetal karyotype was normal. However, with a ratio of less than 2, only 2 of the 38 pregnant women had sex chromosome abnormalities, and 10 of the fetuses were confirmed as positive. CONCLUSION The presence of maternal sex chromosomal abnormalities can greatly influence the result of NIPT, which may also be an important reason for false prediction for fetal SCAs by NIPT. When NIPT indicates abnormal SCAs, it is necessary to analyze maternal sex chromosomes. The ratio of cffDNA(ChrX)/cffDNA may help to determine the source of abnormal signals.

Objective To investigate the influences of maternal gestational diabetes mellitus (GDM) on amino acid levels in neonates.Methods From June 2016 to May 2017,393 pregnancies diagnosed with GDM in Changzhou Maternity and Child Health Care Hospital Affiliated to Nanjing Medical University and 3 924 normal pregnancies were enrolled in this study.Clinical data of the gravidas and their newborns were collected.Heel blood samples were collected at 72 to 96 hours after birth.Tandem mass spectrometry was performed to detect the levels of 11 amino acids including alanine,arginine,citrulline,glycine,leucine/ isoleucine/hydroxyproline,methionine,ornithine,phenylalanine,proline,tyrosine and valine in neonatal heel blood.Differences in amino acid levels between the two groups were compared by t test.Influences of GDM on neonatal amino acid levels were analyzed by multivariate linear regression.Results Compared with the healthy pregnancy group,neonates in the GDM group had higher levels of methionine [(21.01 ±6.30) vs (19.93±6.47) μmol/L,t=3.159,P=0.002] and phenylalanine [(47.19±9.19) vs (45.78±8.58) μ mol/L,t=3.076,P=0.002],but lower levels of alanine [(280.51 ±64.54) vs (290.15±68.40) μ mol/L,t=2.678,P=0.007],proline [(147.64±30.64) vs (152.36±33.57) μ mol/L,t=2.680,P=0.007],tyrosine [(85.21 ±29.50) vs (90.60± 33.32) μ mol/L,t=3.089,P=0.002] and ornithine [(101.22±28.79) vs (105.83±30.10) μmol/L,t=2.906,P=0.004].Multivariate linear regression analysis showed that GDM was responsible for the increase of methionine (β=0.69,95％CI:0.02 to 1.37,P=0.044) and phenylalanine (β=1.60,95％CI:0.69 to 2.51,P=0.001),and the decrease of tyrosine (β=-4.98,95％CI:-8.42 to-1.54,P=0.005) and ornithine (β=-3.16,95％CI:-6.30 to-0.02,P=0.048) in neonates.Conclusions GDM neonates has increased of methionine and phenylalanine levels and decreased tyrosine and omithine levels.

Objective:To express the glycoprotein D of herpes simplex virus type 2 (gD2) in the insect cells,and to determine its immunogenicity.Methods:HSV-2 genome was used as the template for amplification of gD2 extracellular domain fragment gene by PCR.The PCR product was inserted into the vector Bacmind,and the constructed recombinant plasmid gD2-Bacmind was transfected into the sf9 cells to package the recombinant baculovirus.The Sf9 cells were infected by recombinant baculovirus seed derived from the forth passage(P4),the titer of P4 recombinant baculovirus was detected by a plaque assay and the expression of recombinant protein gD2 was determined by Western blotting method.The supernatant of infected cells was collected and purified by Ni-NTA affinity chromatography to obtain the target protein gD2,the purified gD2 protein was used to immunize the BALB/c mice in 0, 2, 4 weeks (gD2 group),and PBS was used as negative control(PBS group);the titers of gD2 specific IgG in serum were detected by ELISA assay.Results: The PCR analysis and sequencing results proved that gD2-Bacmind was constructed correctly.The titer of recombinant baculovirus was 2.0×109 pfu·mL-1,the purified gD2 was about 37 000 with expectation,the percentage of gD2 in total protein was 90%.The average value of Log10 of titer of gD2 specific IgG in serum detected by ELISA assay in gD2 group at the sixth week was 4.34,and there was significant difference compared with PBS group(P<0.01).Conclusion: The gD2 expressed by insect-baculovirus expression vector system has the immunogenicity and can be selected as candidate protein for HSV-2 vaccine.

Objective To understand the infection situation of human T lymphocyte virus(HTLV) among blood donors in Zhongshan area.Methods Blood samples from 40 874 blood donors in Zhongshan from March to December 2016 were screened for HTLV antibody by using,enzyme linked immunosorbent assay(ELISA).The positive samples were reexamined two times,and specimens with positive results of reexamination were detected by using immunohistochemical method(CLIA).Then the positive samples were confirmed by Western blot(WB),and confirmed positive samples were judged as infection.Results Of all 40 874 cases of voluntary blood donors,21 cases were positive with HTLV antibody detected by ELISA,the positive rate of ELISA was 0.05%.Five cases were positive detected by CLIA method.One case was confirmed by WB,and the infection rate was 0.002 4%.Conclusion In order to ensure the safety of blood transfusion and reduce blood transfusion infection of HTLV,it might be necessary to perform HTLV screening in first-time blood donors in Zhongshan area.

Objective: To investigate the inhibitory effect of T-2 toxin on proliferation of the human hepatocellular carcinoma HepG2 cells and its promotion effect of apoptosis.Methods:The HepG2 cells in the logarithmic phase were selected and divided into control group (without T-2 toxin)and experimental groups (given 0.25,2.50,25.00,250.00 and 2500.00 μg·L-1 T-2 toxin).After 24 h treatment,the morphology of cells was observed under inverted microscope;the inhibitory rate of proliferation of cells was determined by MTT assay;the cell cycle and apoptotic rate of cells were analyzed by flow cytometry;Hochest 33258 staining was used to observe the apoptotic morphology of cells;the activity of caspase-3 in HepG2 cells was detected.Results:After treated for 24 h,the inverted microscope observation results showed that the number of the cells in experimental groups was decreased significantly and the cells shrank and deformed.The MTT results showed that compared with control group,the inhibitory rates of proliferation of the cells in experimental groups were increased (P <0.01).The flow cytometry results showed that compared with control group, the percentage of the cells in SubG1 phase in experimental group was significantly increased,and the apoptotic rates of the cells in experimental groups were significantly increased.The Hoechest 33258 staining results showed that the chromatin condensation was observed in the cells in experimental groups,and the nuclei were dense and stained.Compared with control group,the activities of intracellular caspase-3 of the cells in experimental groups were significantly increased (P < 0.01 ). Conclusion:T-2 can inhibit the proliferation of human hepatocellular carcinoma HepG2 cells,and induce the apoptosis.

OBJECTIVETo explore the relationship between temperature and non-accidental mortality in Guangzhou, Changsha and Kunming;to evaluate the temperature-related risk of mortality; and thereby to provide scientific evidence for enacting the policy to tackle climate changes.

METHODDaily meteorology data and mortality data were collected in 2006-2009 in Guangzhou, Changsha and Kunming. Distributed lag non-linear model (DLNM) was established and applied in a case-crossover design, which controlled the secular trend of time, to estimate the specified effects of temperature on non-accidental mortality at conditions of lag 0-2, lag 0-18 and lag 0-27 days, respectively.

RESULTAn obvious seasonal periodicity was found in non-accidental mortality in Guangzhou, Changsha and Kunming during 2006-2009. The mortality number was comparatively high in the winters, and some high temperature days in summer; but was comparatively low in springs and autumn. An L-shaped relationship was found between temperature and mortality in Guangzhou and Kunming and a U-shaped relationship was found in Changsha. When daily mean temperature exceeded 28.2 °C, 24.5°C and 23.2°C, as average temperature increase 1°C, non-accidental mortality increased 4.56% (95%CI:2.74%-6.63%), 5.66% (95%CI:0.22%-12.65%) , -3.94% (95%CI:-32.77%-39.01%) , respectively; when daily mean temperature below 24.8°C, 20.0°C and 17.3°C, as average temperature decrease 1°C, the corresponding increase in non-accidental mortality were 3.28% (95%CI:2.41%-4.10%) (lag 0-18 days), 1.35% (95%CI:0.31%-1.77%) (lag 0-2 days) and 2.42% (95%CI:1.08%-3.27%) (lag 0-27 days) , respectively. The effects of hot weather were acute and short term; while the effects of cold weather had a several days delay, but a longer persistence.

CONCLUSIONSExtreme cold and hot temperature could increase the risk of non-accidental mortality in Guangzhou, Changsha and Kunming. The effects of cold weather had a several days delay, but a longer persistence.

A novel method for the detection of moroxydine ( ABOB) residue in tomatoes was developed based on the enhancement of the fluorescence intensity of CdTe quantum dots( QDs) in the presence of ABOB. The factors influencing the performance of the QDs fluorescent probes were investigated, and the optimum conditions were determined:the concentration of mercaptoacidic acid ( TGA) capped-CdTe quantum dot was 1×10-4 mol/L, and the reaction time was 20 min at pH=5. 6. Under the optimum conditions, the relative fluorescence intensity increases linearly proportional to the ABOB concentration in the range of 1. 0×10-12-5. 0×10-10 mol/L with a limit of detection of 5. 2×10-13 mol/L, R=0. 9981, the recovery was 97%-106%, without obvious interference on the determinations of moroxydine from the common coexisting ions, antibiotics, and vitamins. The proposed method has been successfully applied in the detection of trace moroxydine hydrochloride residue in tomatoes.