Objective To investigate the injury caused by hydrogen peroxide (H2O2) on human renal tubular epithelial cell (HKC) and its effect on calcium oxalate (CaOxa) crystal crystallization time before and after the injury. Methods The injury degree of HKC by H2O2 was measured by detecting the cell survival rate and the concentration change of malonaldehyde (MDA). CaOxa crystallization was investigated by scanning electron microscopy (SEM). Results Control cells induced only a small amount of calcium oxalate dihydrate (COD) crystals, while the injured cells not only induced calcium oxalate monohydrate (COM) crystals, but also increased the number and aggregation of CaOxa crystals. After incubating with CaOxa supersaturated solution, the control group HKC cells could be injured as well. Conclusions H2O2 can cause oxidative damage on HKC. The injured HKC promotes the nucleation and aggregation of COM crystals. In the body environment, the long-term presence of crystals in urinary tract is a risk factor for stone formation.

Objective To investigate healthcare-associated infection(HAI)in patients in a cancer hospital,provide reference for controlling HAI in cancer patients,and guide rational use of antimicrobial agents.Methods Clinical data of patients in a cancer hospital between August 2006 and July 2012 were analyzed retrospectively.Results The incidence of HAI case was 1 .53% (2 060/134 389),and annual incidence showed a downward trend.The main in-fection site was lower respiratory tract (46.46%,n=957),followed by bloodstream (15.63%,n=322),abdominal and pelvic (14.03%,n=289).The main pathogens were Pseudomonas aeruginosa (16.16%,n=350),Staphylo-coccus aureus (9.97%,n=216),Klebsiella pneumoniae (9.79%,n=212),Escherichia coli (9.65%,n=209), and Candida albicans (6.51 %,n=141 ).Gram-negative bacilli,including Klebsiella pneumoniae and Escherichia coli ,were sensitive to carbapenems and β-lactamase inhibitors.Conclusion Lower respiratory tract is the major HAI site in patients with cancer,and gram-negative bacteria are the main pathogens.Carbapenems andβ-lactamase inhibitors are recommended for the empirical treatment of HAI in cancer patients.

Objective To investigate the role of Notch signaling in the progression of peritoneal fibrosis in a rat model induced by high glucose dialysate. Methods Male Sprague Dawley rats were subjected to daily peritoneal dialysis (PD) with a lactate-buffered solution containing 4.25% glucose. They were sacrificed at 2 and 4 weeks after PD. The parietal thickness was measured with Masson staining. The expression of TGF-β1, E-cadherin, α-SMA and collagen Ⅰ was examined by immunoblotting. The expression of Notch ligand Jagged-1 and the negative Notch signaling regulato--Numb was analyzed by both immunoblotting and RT-PCR. The expression of a Notch nuclear target gene Hcs-1 was examined by RT-PCR. Results Both HE and Masson trichrome staining revealed an increase in peritoneal thickness with a loss of mesothelial cells and a rich of collagen matrix deposition in the submesothelial zone was evident at 4 weeks after PD. Meanwhile, compared to healthy rats, the expression of TGF-β1, ct-SMA and collagen Ⅰ was significantly increased, but the expression of E-cadherin was decreased in peritoneum after PD treatment. It was difficult to detect the Jagged-1 and Hes-1 expression in normal peritoneum, but their expression was graduaUy increased after PD. In contrast, the expression level of Numb, a negative regulator of Notch signaling, was dramatically decreased after PD. Conclusions Notch signaling is activated during the process of PD-induced peritoneal fibrosis and the activation of Notch signaling is associated with the loss of negative regulation of Notch signaling via decreased expression of Numb. Inhibition of Notch signaling via overexpression of its negative regulators such as Numb may be a novel therapeutic approach for peritoneal fibrosis in PD patients.

Coronavirus disease 2019 (COVID-19) epidemic is the most widespread global pandemic in the past 100 years. Person-to-person transmission of COVID-19 infection leads to the major threat of human safety and health. At 00:00 on January 24th, 2020, Tianjin City launched the first-level response to the COVID-19 epidemic. At 18:00 on the same day, Management Committee of Dongjiang Free Trade Port Zone of Tianjin received areport that there were 15 people who had fever on the Costa Crociere carrying 4 806 people from Japan back to the home port of Tianjin Dongjiang Cruise. At the same time, there are more than 140 Chinese Hubei tourists. Tianjin Municipal Committee and Government, Tianjin Customs, Binhai New Area District Committee Government, Tianjin Health Commission, Tianjin Binhai New Area Health Commission formed an emergency command center immediately to deal with the epidemic comprehensively. At 06:40 on January 25th, 2020, the medical investigation team made up by Tianjin Binhai New Area Health Commission and Tianjin East Administration of Customs boarded the cruise ship. With reference to the customs inspection and quarantine regulations, in accordance with the Diagnosis and treatment of pneumonia caused by novel coronavirus (trial version 3) for mulated by the National Health Commission of the People's Republic of China and the Novel coronavirus infected pneumonia port control and technology plan (first version) formulated by the General Administration of Customs, combined with the actual situation of cruise ships, the medical investigation team developed the inspection standards, including door-to-door inspections, temperature measurement and epidemiological investigations on all persons on board of the cruise ship. A total of 4 806 person-times were investigated in the affected area, including 3 706 tourists and 1 100 crew members. Seventeen people at high risk of COVID-19 were identified, including three Wuhan tourists. The reports of 2019 novel coronavirus (2019-nCoV) nucleic acid detection on throat swab samples for those who were identified as high risk were returned as all negative at 14:54 on the same day. At 19:30, the medical investigation team completed the investigation and evacuated the cruise ship. The temperature measurement, medical observation and resettlement of passenger were handed over to relevant personnel. After 2 weeks, the follow-up result of 2019-nCoV nucleic acid of 17 high risk people were all negative. The overall command and comprehensive coordination of the onshore command center together with the rigid principles and excellent responds ability of the on-site epidemic investigation team ensured the successful completion of the epidemic investigation work, and also provided reference for further improving the management and disposal capacity of public health emergencies at sea.

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.