[Expression and clinical significance of plasma methylated SEPT 9 gene in patients with primary liver cancer].

Objective: To investigate the expression and clinical significance of plasma methylated SEPT9 (mSEPT9) gene in patients with primary liver cancer. Methods: 393 cases who visited our hospital from May 2016 to October 2018 were selected. Among them, 75 cases were in the primary liver cancer (PLC) group, 50 cases were in the liver cirrhosis (LC) group, and 268 cases were in the healthy control group (HC). The three groups' positive rates of mSEPT9 expression in the peripheral plasma were detected by the polymerase chain reaction (PCR) fluorescent probe method. The correlational clinical features of liver cancer were analyzed. At the same time, the electrochemiluminescence detection method was used to compare the AFP positive rate. Statistical analysis was conducted using chi-square tests or continuity-corrected chi-square tests. Results: 367 cases actually had valid samples. There were 64, 42, and 64 cases in the liver cancer group, cirrhosis group, and healthy control group, respectively. Among them, 34 cases of liver cancer were verified from pathological tissues. The positive rate of plasma mSEPT9 was significantly higher in the liver cancer group than that in the liver cirrhosis and healthy control groups [76.6% (49/64), 35.7% (15/42), and 3.8% (10/261), respectively], and the differences were statistically significant (χ (2) = 176.017, P < 0.001). The sensitivity of plasma mSEPT9 detection (76.6%) was significantly better in liver cancer (76.6%) than that of AFP patients (54.7%), and the difference was statistically significant (χ (2) = 6.788, P < 0.01). Compared with the single detection, the sensitivity and specificity of plasma mSEPT9 combined with AFP were significantly improved (89.7% vs. 96.3%, respectively). Patients with liver cancer aged≥50 years, with clinical stage II or above, and those with pathological signs of moderate to low differentiation had higher levels of plasma mSEPT9 positive expression, and the differences were statistically significant (χ (2) = 6.41, 9.279, 6.332, P < 0.05). During the follow-up period, the survival time of liver cancer patients with positive plasma mSEPT9 expression was significantly shorter than that of those with negative expression (310 ± 26 days vs. 487 ± 59 days, respectively), with statistically significant differences (Log Rank P = 0.039). Conclusion: In China, the positive rate of plasma mSEPT9 detection in liver cancer patients is higher than that of AFP in relation to age, clinical stage, and degree of tissue differentiation; additionally, it has certain survival predictive values. As a result, detecting this gene has important clinical significance and potential clinical application value in the non-invasive diagnosis and prognosis assessment of patients with primary liver cancer.

A novel approach to correct the coded aperture misalignment for fast neutron imaging.

Aperture alignment is crucial for the diagnosis of neutron imaging because it has significant impact on the coding imaging and the understanding of the neutron source. In our previous studies on the neutron imaging system with coded aperture for large field of view, "residual watermark," certain extra information that overlies reconstructed image and has nothing to do with the source is discovered if the peak normalization is employed in genetic algorithms (GA) to reconstruct the source image. Some studies on basic properties of residual watermark indicate that the residual watermark can characterize coded aperture and can thus be used to determine the location of coded aperture relative to the system axis. In this paper, we have further analyzed the essential conditions for the existence of residual watermark and the requirements of the reconstruction algorithm for the emergence of residual watermark. A gamma coded imaging experiment has been performed to verify the existence of residual watermark. Based on the residual watermark, a correction method for the aperture misalignment has been studied. A multiple linear regression model of the position of coded aperture axis, the position of residual watermark center, and the gray barycenter of neutron source with twenty training samples has been set up. Using the regression model and verification samples, we have found the position of the coded aperture axis relative to the system axis with an accuracy of approximately 20 µm. Conclusively, a novel approach has been established to correct the coded aperture misalignment for fast neutron coded imaging.

[Epidemiological trend in late stage of control in Malayan filariasis endemic areas with Anopheles anthropophagus as main vector].

During 1982-1990, a longitudinal observation on prevalence trend of malayan filariasis has been made in endemic areas with An. anthropophagus as the main vector. A total of 22,795 person-times of blood examination were made, and 30,439 An. anthropophagus and 10,061 An. sinensis were dissected respectively. The microfilaraemia rate dropped from 1.0% to 0.14%, and the infection rate of An. anthropophagus decreased from 0.74% to 0.09% in 3 endemic villages, while no positive case or infected vector occurred in 5 villages where microfilaraemia cases were absent since the beginning of the study. In a cross-sectional survey, 855 villages of 17 counties has been monitored for 10 years. Out of 213,934 person-times of blood examination, only 56 were positive, the average microfilaraemia rate being 0.0262%, and 94.64% of the positive had already been detected before 1986. Based on these data, it has been suggested that in endemic areas with An. anthropophagus as main vector, when the microfilaraemia rate dropped to less than 1% after control, there was no indication that the rate would upgrade during the survey period. A decline trend of the transmission of malayan filariasis, therefore, has been exhibited.