ABSTRACT
BACKGROUND: Infection with Neisseria gonorrhoeae in adults usually leads to vaginitis and acute urethritis, and infection through the birth canal in newborns can lead to acute neonatal conjunctivitis. In view of certain factors such as a high missed detection rate of N.gonorrhoeae from staining microscopy method, the time-consuming nature and limited sensitivity of bacterial culture method, complicated and inability of absolute quantification from the ordinary PCR method. METHODS: This study aims to establish a ddPCR system to detect N.gonorrhoeae in a absolute quantification, high specificity, high stability and accurate way. We selected the pgi1 gene as the target gene for the detection of N.gonorrhoeae. RESULTS: The amplification efficiency was good in the ddPCR reaction, and the whole detection process could be completed in 94 min. It has a high sensitivity of up to 5.8 pg/µL. With a high specificity, no positive microdroplets were detected in 9 negative control pathogens in this experiment. In addition, ddPCR detection of N.gonorrhoeae has good repeatability, and the calculated CV is 4.2 %. CONCLUSIONS: DdPCR detection technology has the characteristics of absolute quantification, high stability, high specificity and high accuracy of N.gonorrhoeae. It can promote the accuracy of the detecting of N.gonorrhoeae, providing a more scientific basis for clinical diagnosis and treatment.
ABSTRACT
Background: Body mass index (BMI) has been associated with a risk of esophageal cancer. However, the influence of BMI and BMI loss on people with esophageal cancer that were treated with different therapies has not been described in China. Methods: In total, 615 consecutive patients that underwent esophagectomy and/or chemotherapy/radiotherapy were classified according to the Asian-specific BMI (kg/m2) cutoff values. The impact of BMI and BMI loss on long-term overall survival (OS) was estimated using the Kaplan-Meier method and Cox proportional hazard models. Results: Multivariate analysis showed that overweight and obese patients had a more favorable survival than normal weight and underweight patients (p=0.017). Patients with a low BMI and high BMI loss before therapy had worse OS than others (p=0.001). Subgroup analysis showed that patients with a high BMI were more likely to suffer hypertension (p<0.001) and receive only surgery (p<0.001), and they were less likely to be smokers (p=0.007) and anemic (p<0.001). Conversely, patients with high BMI loss were more likely to be anemic (p=0.001), to have advanced pathological stage (p=0.012), and to receive chemotherapy and radiotherapy (p=0.001). Moreover, the mortality rate was higher when patients had a high BMI loss. There is no survival benefit of higher BMI in the non-esophageal squamous cell carcinoma (ESCC) group. Conclusion: Pretreatment BMI was an independent prognostic factor for long-term survival in esophageal cancer patients treated with different treatments. The overall survival was increased in esophageal cancer patients with a high pretreatment BMI and no BMI loss. There is no survival benefit of higher BMI in the non-ESCC group.
ABSTRACT
How to effectively improve the tracking and erosion resistance of silicone rubber (SR) was an urgent topic in the field of high-voltage insulation. In this work, the tracking and erosion resistance of SR was significantly improved by incorporating platinum (Pt) catalyst and nitrogen-containing silane (NS). The suppression effect and mechanism of Pt/NS on tracking and erosion were studied by inclined plane (IP) test, thermogravimetry (TG), thermogravimetry-Fourier transform infrared spectrometry, laser Raman spectroscopy, and scanning electron microscopy. It revealed that when 1.4 phr of NS and 6.7 ppm of Pt were added, the tracking resistance of SR was improved from 2.5 to 4.5 kV level in the IP test, and the eroded mass was significantly reduced. This might be attributed to the synergistic effect of Pt/NS on silicone chains. At a high temperature produced by arc discharge, Pt/NS would catalyze radical cross-linking, meanwhile suppressing oxidation and depolymerization of silicone chains. Hence, a tightly cross-linked network was formed and protected inner materials from arc ablation. Moreover, carbon deposit during pyrolysis was suppressed by Pt/NS, which served as the secondary mechanism of tracking suppression.
