ABSTRACT
Objective To establish a Real-time quantitative PCR method (qPCR) for the detection of diatom UPA barcoding genes and evaluate its application in the drowning diagnosis. Methods The homologous sequences of diatoms UPA gene was obtained by Blast from GeneBank, based on which the universal primers for diatoms were designed. DNA were extracted from 2 common human symbiotic bacteria (Escherichia coli, Bifidobacterium longum), 3 species of planktonic bacteria, 15 species of planktonic algae, tissue samples (lung, liver and kidney) from human cadavers (28 drowning victims, 1 victims by non-drowning in the water, 3 victims deaths on land) in 32 cases. The specificity, sensitivity and repeatability of the designed primers were tested. The positive rates of diatoms detection in the drowning cases were calculated. The results of the real-time quantitative method were evaluated comparatively by Microwave Digestion-Vacuum Filtration-Automated Scanning Electron Microscopy (MD-VF-Auto SEM) and PCR-Capillary Electrophoresis (PCR-CE). Results The results showed that the primers UPA99 had strong specificity for the diatomaceae (Synedra radians, Navicula sp., Melosira varians, Cyclotella sp. and Nitzschia sp.) DNA. The melting curve of the amplified product was smooth; the peak was narrow; the melting temperature was (87±1)℃. The sensitivity of qPCR method was 1.56×10-5ng/μL with the detection range of 1.56×102ng/mL~1.56×10-5ng/μL, in contrast with the PCR-CE method (1.56×10-3ng/μL). This real-time PCR method showed high repeatability and stability with the coefficient of variation less than 2%. The detection rate of lung, liver and kidney was 89.3%, 71.4% and 64.3% respectively. Conclusion The established qPCR method, based on the universal primers designed for diatom UPA gene, has high specificity, high sensitivity and good repeatability. With a promising prospect for application, qPCR is suitable for drowning diagnosis.
ABSTRACT
A novel method based on cross sensitivity of cataluminescence (CTL) on nano-Ti3CeY2O11 was proposed for simultaneous determination of formaldehyde, benzene and sulfur dioxide in air.The relations between the concentrations of formaldehyde, benzene and sulfur dioxide and their CTL intensities were respectively ascertained at three wavelengths.The accurate concentrations of formaldehyde, benzene and sulfur dioxide can be calculated by superimposed total CTL intensities.The three analysis wavelengths are 420 nm, 535 nm and 680 nm.The surface temperature of the sensitive materials is 280℃.The carrier gas flow rate is 130 mL/min.The detection limits (3σ) are 0.04 mg/m3 for formaldehyde, 0.05 mg/m3 for benzene and 0.10 mg/m3 for sulfur dioxide, respectively.The linear ranges of CTL intensity versus analyte concentration are 0.08-75.60 mg/m3 for formaldehyde, 0.1-101.40 mg/m3 for benzene and 0.3 to 115.00 mg/m3 for sulfur dioxide.The recoveries of 12 testing standard samples by this method are 96.4%-103.7% for formaldehyde, 97.8%-102.5% for benzene and 97.2%-103.3% for sulfur dioxide.Common coexisting substances, such as acetaldehyde, toluene, hydrogen sulfide, ammonia, methanol, ethanol and carbon dioxide, do not disturb the determination.The relative deviation of CTL signals of continuous 200 h detection for gaseous mixture containing formaldehyde, benzene and sulfur dioxide is less than 2%, which shows the longevity of the nanometer composite oxide to formaldehyde, benzene and sulfur dioxide.This method makes full use of the cross sensitive phenomenon, and can realize the on-line analysis of formaldehyde, benzene and sulfur dioxide in air.
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Objective · To investigate association between serum 25-hydroxyvitamin D3 [25(OH)D3] level and diabetic peripheral neuropathy (DPN) in elderly patients with type 2 diabetes mellitus and explore its value in clinical practice for early screening and prevention of DPN. Methods · A total of 188 elderly patients with type 2 diabetes mellitus were enrolled in this cross-sectional study, including 100cases with DPN and 88 cases without. Clinical data was collected and serum levels of 25(OH)D3, glycosylated hemoglobin (HbA1c), blood lipids and hepatic and renal functions were determined in all patients. Spearman correlation analysis was used to evaluate relationship between each index and 25(OH)D3, and Logistic regression was used for statistical analysis of risk factors for DPN. Results · The median of serum 25(OH)D3 level was significantly lower in the patients with DPN (34.95 nmol/L) than that of the patients without DPN (52.6 nmol/L)(P<0.01). Spearmancorrelation analysis showed that there existed a negative correlation between the level of 25(OH)D3 and age, HbA1c and fasting blood glucose (r=-0.37, -0.53, and -0.29, respectively, P<0.01). The multiple Logistical regression analysis revealed that the 25(OH)D3 level was an independent risk factor for DPN. The odds ratio of serum 25(OH)D3 was 15.5 (OR=15.50, 95% CI=2.00 ~ 119.62) for the lowest quartile versus the highest quartile. Conclusion · The decreased level of 25(OH)D3 may increase risks for the occurrence of DPN in the elders with type 2 diabetes mellitus and monitoring the level of 25(OH)D3 contributes to early detection of DPN.
ABSTRACT
Frailty is an important geriatric syndrome and has gradually become one of the major focuses in geriatric research.Frailty is the result of interaction between multiple factors working on multiple systems,and is closely related to adverse health consequences.Therefore,early identification and assessment of frailty is very important for effective management of high risk individuals.This article reviews the current frailty assessment tools and examines their advantages and disadvantages.