Objecive To evaluate the causes of 60 cases for clinical failure in post crown.Methods Sixty cases with failure in post crown cure were entered the study.The causes of failure were analyzed.Results Among the 60 cases with failure in post crown cure,38 cases were due to the crown'loosing or broken away,12 cases with the broken dental crown,10 cases with periapical periodontitis,6 cases with broken root.Conclusions It was the loosing or broken away of post crown,periapical periodontitis,dental crown and root broken consist of the main causes for clinical failure in post crown.

Digital polymerase chain reaction (dPCR) is an absolute quantitative technique that has been rapidly developed in recent years. This technique assigns the reaction system containing DNA template to a large number of independent reaction units for PCR, and calculates the DNA copy number according to the Poisson distribution and statistical positive signals. In contrast to conventional qPCR, dPCR does not depend on amplification curves, is not affected by amplification efficiency, thus has high accuracy and repeatability, and can achieve the absolute quantification. This article reviews the development history of dPCR and its application in molecular diagnosis, tumor liquid biopsy and prenatal diagnosis of infectious diseases, and looks forward to the application prospect of this technology.

Objective:To establish a method of serum detection by Raman spectroscopy for the diagnosis of gastric cancer.Methods:Between April and November 2019, 110 patients with gastric cancer [73 males, 37 females, age (57.4±10.3) years] and 74 patients with colorectal cancer [48 males and 26 females, aged (58.3±12.2) years] were collected at the First Affiliated Hospital of Army Military Medical University, along with 100 healthy subjects [59 males and 41 females, aged (55.6±10.61) years] during the same period. Fasting venous blood serum samples were collected from the subjects. A Raman spectrometer XploRA PLUS was used in this experiment, with an excitation light source of 532 nm, a field of view of 100 times, and a spectrum range of 200-2 000 cm -1, etc. The serum samples were detected by nondestructive and non-contact rapid detection, and the Raman spectra of serum samples were collected. Using the Raman spectrum acquisition and processing supporting software LabSpec6 to smooth, baseline, and normalize the obtained Raman spectrum. Multivariate statistical analysis software SIMCA14.1 were applied to import and analyze the obtained Raman spectrum data by principal component analysis (PCA), orthogonal partial least squares discriminant analysis (OPLS-DA), and other methods for statistical analysis. An operating characteristic curve (ROC) was constructed to evaluate the model analysis effect between serum samples of healthy people and those with gastric cancer. Serum samples from the colorectal cancer group were used to verify the reliability of the model. Results:Six Raman peaks with good repeatability were detected in serum samples in health and gastric cancer group, and peaks were located at 1 001.17, 1 154.63, 1 337.89, 1 446.85, 1 515.33, and 1 658.34 cm -1, respectively. Raman intensities at six Raman peaks were significantly different between healthy and gastric cancer groups. At the displacement of 1 001.17, 1 154.63, and 1 515.33 cm -1, the Raman intensity in the healthy group was higher than that in the gastric cancer group. At 1 337.89, 1 446.85, and 1 658.34 cm -1 displacement, the Raman intensity of the gastric cancer group was higher than that of the healthy group. An OPLS-DA model was constructed to analyze the serum samples of the healthy group and the gastric cancer group. In the model, R 2 is the fitting power, and Q 2 is the predictive ability. The closer the values of R 2 and Q 2 are to 1, the better the performance of the model, and the obtained model's R 2X(cum)=0.809, R 2Y(cum)=0.819, Q 2(cum)=0.758. ROC characteristic curve was drawn based on the OPLS-DA model. The area under the curve (AUC) of the gastric cancer group was 0.998. Six peaks with good repeatability were detected in the serum Raman spectra of gastric cancer stage Ⅰ, Ⅱ, Ⅲ, and Ⅳ, which were located at the displacement of 1 001.85, 1 155.07, 1 338.36, 1 445.75, 1 515.92, and 1 657.68 cm -1, respectively, and at the displacement of 1 155.07 and 1 515.92 cm -1. The Raman intensity of gastric cancer stage Ⅳwas significantly higher than that of gastric cancer stages Ⅰ, Ⅱ, and Ⅲ. Conclusions:According to the model reliability verification, the healthy group, gastric cancer group and colorectal cancer group can also be effectively separated based on OPLS-DA results; it showed a good performance in separating the healthy group from the gastric cancer group. It is possible to detect serum samples from healthy people and gastric cancer patients unlabeled by combining Raman spectroscopy and the OPLS-DA method in multivariate statistics.

Objective To investigate the onset of liver inflammation and related predictive factors in patients with HBeAg-positive chronic hepatitis B virus (HBV) infection who have normal alanine aminotransferase (ALT) and a high viral load. Methods A retrospective analysis was performed for the clinical data of 183 patients with HBeAg-positive chronic HBV infection who had normal ALT and a high viral load and were treated from October 2008 to May 2015, and according to the results of liver biopsy, they were divided into hepatitis group and non- hepatitis group. The t -test or Mann-Whitney U testwas used for comparison of normally distributed continuous data between groups, the chi-square test was used for comparison of categorical data. The predictive factors were analyzed by univariate binary logistic regression, the multivariate binary logistic regression was carried out by stepback method, and the cut-off values were analyzed by receiver operating characteristic curve (ROC) and Jordan index. Results There were 37 patients (20.2%) in the hepatitis group and 146 patients (79.8%) in the non-hepatitis group. Compared with the non-hepatitis group, the hepatitis group had a significantly lower proportion of male patients (45.9% vs 68.5%, χ 2 =6.508, P =0.011), a significantly higher level of aspartate aminotransferase [24 (21.25~35.55) U/L vs 21.2 (18.08~ 24.65) U/L, Z =-3.344, P =0.001], and a significantly lower log(HBsAg) value [4.4(4.28~4.49) vs 4.46(4.4~4.74), Z =-2.184, P =0.029]. Log(HBsAg) value was a predictive factor for hepatitis (odds ratio=0.077, P =0.017), and the cutoff value of HBsAg was 33884.4I U/mL. Conclusion Among the patients with HBeAg-positive chronic HBV infection who have normal ALT and a high viral load, 20.2% have liver inflammation, and HBsAg may be a predictive factor for liver inflammation.