DNA Matrix Operation Based on the Mechanism of the DNAzyme Binding to Auxiliary Strands to Cleave the Substrate.

Numerical computation is a focus of DNA computing, and matrix operations are among the most basic and frequently used operations in numerical computation. As an important computing tool, matrix operations are often used to deal with intensive computing tasks. During calculation, the speed and accuracy of matrix operations directly affect the performance of the entire computing system. Therefore, it is important to find a way to perform matrix calculations that can ensure the speed of calculations and improve the accuracy. This paper proposes a DNA matrix operation method based on the mechanism of the DNAzyme binding to auxiliary strands to cleave the substrate. In this mechanism, the DNAzyme binding substrate requires the connection of two auxiliary strands. Without any of the two auxiliary strands, the DNAzyme does not cleave the substrate. Based on this mechanism, the multiplication operation of two matrices is realized; the two types of auxiliary strands are used as elements of the two matrices, to participate in the operation, and then are combined with the DNAzyme to cut the substrate and output the result of the matrix operation. This research provides a new method of matrix operations and provides ideas for more complex computing systems.

Hepatitis B virus serological screen in a general hospital in Beijing from 2008 to 2018, and challenges to our vaccination policy.

OBJECTIVE: Hepatitis B virus (HBV) has a worldwide distribution and remains a leading public health problem in China. METHOD: Automated chemiluminescence microparticle immunoassay was used to test all five markers of HBV serology in serum samples among 696,048 patients, pregnant women, and normal subjects in Beijing from 2008 to 2018. RESULTS: The overall prevalence of subjects categorized as previous/ occult HBV infection, inactive HBsAg carrier, active HBV infection, HBsAg, HBV susceptible, and immune via vaccination was 29.4%, 4.8%, 1.4%, 6.4%, 33.9% and 30.3%, respectively; men had a significantly higher prevalence of HBV infection than women. The prevalence of HBsAg was around 0.5% in subjects ≤ 10 years of age, increased dramatically to 3.7% in subjects between 11 and 20 years of age, reached the highest level of 7.9% in subjects between 41 and 50 years of age, and finally decreased to 2.8% in subjects ≥ 81 years of age. During the 10 years from 2008 to 2018, the prevalence of HBsAg was stabilized at about 6.0%, and indicators of HBV susceptibility, previous/ occult HBV infection, and immunity via vaccination were not further improved, despite the constant implementation of HBV vaccination since 1992. All four age groups (21 - 30y, 31 - 40y, 41 - 50y and 51 - 60y) of the normal adult population were found to have a significantly lower prevalence of HBsAg and HBV susceptibility but significantly higher prevalence of immunity via vaccination compared with corresponding age groups of the sub-total population. CONCLUSIONS: Although high coverage has been established among infants and young children, their vaccination alone could not reduce HBV infection in the adult Chinese population quickly. Adult populations with more vaccinated individuals are found to have fewer individuals with HBsAg. Vaccination in adults or at least in high-risk adults is an urgent need to decrease horizontal HBV transmission in China.

Cytomegalovirus antigenemia in patients with autoimmune and non-autoimmune diseases in Beijing: A 10-year single hospital experience.

BACKGROUND: Primary cytomegalovirus (CMV) infection is prevalent worldwide and usually results in latency in immunocompetent populations. Reactivation of latent CMV can cause life-threatening complications in immunocompromised hosts. METHODS: We used the CMV Brite assay to test CMV antigenemia (pp65) in whole blood samples from 22,192 patients with or without autoimmune diseases in Beijing during 2008-2018. RESULTS: The overall prevalence of CMV antigenemia was 19.5% (9.7%, males; 26.0%, females). The prevalence of CMV antigenemia was 35.1%, 58.6% and 11.4% in whole patients with autoimmune diseases, in patients with systemic lupus erythematosus (SLE) and in patients with non-SLE autoimmune diseases, respectively. All patients with non-autoimmune diseases, patients with HIV/AIDS or transplantation were found to have 5.0%, 27% or 14.8%, respectively. Patients≤20 years with SLE had a significantly higher prevalence of CMV antigenemia than did all SLE patients, on average. Patients>51 years with non-SLE autoimmune diseases had a significantly higher prevalence than did all patients with non-SLE autoimmune diseases, on average. The prevalence of CMV antigenemia in patients admitted to intensive-care units (ICUs) were 9.2%, which was significantly higher than that among all patients with non-autoimmune diseases. Patients with SLE had 23.8% of negative conversion of CMV antigenemia, significantly lower than the percentage of patients with non-SLE autoimmune (64.3%) and non-autoimmune (61.0%) diseases. The mean number of days to negative conversion of CMV antigenemia in patients with SLE was 35.3±35.8 days, which was significantly longer than that in patients with non-SLE autoimmune diseases (15.4±11.9 days) and non-autoimmune diseases (13.6±7.7 days). CONCLUSIONS: CMV antigenemia is found more likely in women than in men, more prevalently in patients with SLE than those with HIV/AIDS or transplant recipients, more frequently in patients admitted to ICUs. Patients with SLE had prolonged CMV antigenemia. The role of CMV appears important in SLE.

[Indication of tracheostomy extubation in patients with severe neuropathy: a Meta-analysis].

OBJECTIVE: To analyze the extubation indications of tracheotomy patients with severe neuropathy by Meta-analysis in order to determine the effective indication parameters for successful extubation. METHODS: The literatures in databases including China National Knowledge Infrastructure (CNKI), Wanfang, VIP, Web of Science, PubMed and Cochrane Library were retrieved from their establishment to April 2019. The literatures were case-control studies, cohort studies, randomized controlled trials (RCTs) or surveys related to indication parameters for successful extubation in patients with severe neuropathy. Two researchers identified and extracted literatures and data independently. The quality of literatures was assessed by the Newcastle-Ottawa scale (NOS). Meta-analysis was performed by RevMan 5.3 software. The stability of the results were evaluated by assessing the statistical models (the fixed effects model or the random effects model) and literatures quality (inferior or superior), and by sensitivity analysis. The publication bias of literatures was assessed by funnel plot. RESULTS: Eleven studies involving 1 357 participants were enrolled, and the rate of successful extubation was 46.7%-97.5%. Nine studies defined successful extubation as no need of re-intubation, and other two did not explain. All studies were high quality research, with NOS score of 6-8. Meta-analysis showed that the correlation between the level of consciousness [Glasgow coma score (GCS) ≥ 8 vs. < 8: odds ratio (OR) = 3.34, 95% confidence interval (95%CI) was 2.22-5.03, P < 0.001], the amount of tracheal secretions (less vs. more: OR = 13.07, 95%CI was 5.64-30.32, P < 0.001), cough reflex (with vs. without: OR = 14.33, 95%CI was 6.36-32.28, P < 0.001), swallowing function (good vs. bad: adjusted OR = 18.56,95%CI was 8.16-42.21, P < 0.001) and successful extubation was statistically significant, and the correlation between the pulmonary infection (with vs. without: adjusted OR = 1.94, 95%CI was 0.87-4.35, P = 0.11), oxygen saturation (≥ 0.95 vs. < 0.95: OR = 2.34, 95%CI was 1.11-4.91, P = 0.12), tolerance of tube plugging (good vs. bad: OR = 2.12, 95%CI was 0.67-6.71, P = 0.20), method of tube drawing (gradually vs. abruptly: OR = 0.99, 95%CI was 0.95-1.04, P = 0.93) and successful extubation was not statistically significant. Sensitivity analysis showed that the results were stable. Funnel plot showed that the studies distributed in both sides of the funnel symmetrically, indicating the publication bias of literatures was small. CONCLUSIONS: The effective indication of extubation is consciousness level (GCS score ≥ 8), less secretion, cough reflex and good swallowing function.

A retrospective seroepidemiologic survey of Chlamydia pneumoniae infection in patients in Beijing between 2008 and 2017.

BACKGROUND: Chlamydia pneumoniae (C. pneumoniae) is an obligate intracellular bacterium and a human pathogen that causes respiratory infectious diseases. More than 50% of the adult population worldwide was once infected with C. pneumoniae, but investigations into this topic are insufficient in mainland China. METHODS: Anti-C. pneumoniae IgG and IgM antibodies were detected using micro-immunofluorescence test in serum samples of patients visiting Peking Union Medical College Hospital between 2008 and 2017 for routine medical purposes, and the aim of this retrospective study was to analyze the test results. RESULTS: Among 12,050 serum specimens tested for anti-C. pneumoniae IgG and IgM antibodies, the overall prevalence of anti-C. pneumoniae IgG antibodies was 86.6%, 87.2% for men and 86.0% for women. Adult men (>20 years) were found to have a significantly higher prevalence of anti-C. pneumoniae IgG than women (χ2 = 30.32, P = 0.000). 3 to 5 years old patients were observed to have the lowest prevalence of anti-C. pneumoniae IgG, 42.8%, then increased with age, reaching the highest level of 98.6% in patients over 70 years of age. In the 10,434 specimens with C. pneumoniae IgG antibodies, the total geometric mean titer (GMT) for C. pneumoniae IgG was 45.71. Although GMTs were found to be significantly higher among all men than among all women (t = 5.916, P = 0.000), sex difference actually began in patients over 40 years of age and increased in the elderly. In the total 12,050 specimens, 1.2% had anti-C. pneumoniae IgM, 3.3% had anti-C. pneumoniae IgG with titers equal to or greater than 1:512; 0.39% had ≥4-fold increasing titers of antibodies in acute and convalescent phase paired samples, and 4.4% were finally confirmed to have acute antibodies against C. pneumoniae. 6 to 10 years old patients were found to have the highest rate of both IgM antibodies (3.9%) and acute antibodies (6.2%) against C. pneumoniae. Acute antibodies against C. pneumoniae were found to be more frequent in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD, 14.0%, χ2 = 20.43, P = 0.000), patients with pneumonia (7.8%, χ2 = 51.87, P = 0.000) and patients with acute respiratory tract infection (12.3%, χ2 = 60.91, P = 0.000) than among all patients (4.4%). Both anti-C. pneumoniae IgG and IgM antibodies should be tested for acute antibodies against C. pneumoniae as testing for either alone will underestimate by a maximum of two-thirds the incidence of acute antibodies against C. pneumoniae. CONCLUSIONS: More than 86% of Chinese patients on an average were once infected with C. pneumoniae. Adult men had both a higher prevalence and higher levels of antibodies than women. 6 to10 year old patients were found to have the most frequent acute infection of C. pneumoniae. C. pneumoniae is associated with AECOPD, pneumonia and acute respiratory tract infection. Anti-C. pneumoniae IgG and IgM should be tested simultaneously to avoid underestimation of acute antibodies against C. pneumoniae.

Anti-Epstein-Barr virus antibodies in Beijing during 2013-2017: What we have found in the different patients.

BACKGROUND: Epstein-Barr virus (EBV) is associated with nasopharyngeal carcinoma (NPC) which is prevalent in South China, and its association with systemic lupus erythematosus (SLE) or other autoimmune diseases has not been studied in the mainland of China. The EBV serological tests have been performed on patients with various diseases or manifestations for years at our institution and their values need to be evaluated. METHODS: For routine medical purposes, anti-EB viral capsid antigen (VCA) IgG, IgA and IgM antibodies, anti-EBV diffuse early antigen (EA-D) IgA antibodies, and anti-EBV nuclear antigen-1(EBNA-1) IgG antibodies were tested with commercial enzyme-linked immunosorbent assay (ELISA) in patients visiting Peking Union Medical College Hospital between 2013 and 2017. The test results were analyzed in this retrospective study. RESULTS: There were a total of 11122 serum samples available to be tested in the study. As indicators of past EBV infection, the prevalence of VCA-IgG/EBNA1-IgG were 66.6%/58.5%, 84.3%/78.8%, 92.9%/87.0% and 98.5%/95.4% in patients aged under 5 years, 6-10 years, 11-20 years and 21-30 years old, respectively, and these values maintained at this highest rate as age increased further. The prevalence of VCA-IgM, as a parameter of acute EBV infection, was 14.6%, 10.2%, 10.4%, 6.3% and 3.1% in patients aged under 5 years, 6-10 years,11-20 years, 21-30 years, 31-40 years old, respectively, and decreased to 2%~3% in older patients. Patients with elevated serum liver enzymes were more likely to have a higher prevalence of EA/D IgA antibody (P < 0.01) and young patients (≤30 years) with lymphadenopathy were more likely to have higher prevalence of VCA-IgM antibody (P < 0.01). The prevalence of VCA-IgA and EAD-IgA were 87.0% and 59.2% in NPC patients, respectively, and both were significantly higher (P < 0.001) than that in non-NPC patients. The prevalence of VCA-IgA was 45.4% and 25.6% in SLE patients and patients with other autoimmune diseases, respectively, which were significantly (P < 0.001) and mildly (P = 0.039) higher than their controls. In pediatric SLE patients between 6 and10 years old, the prevalence of VCA-IgG, VCA-IgA and EBNA1-IgG was 100%, 59.5% and 100%, respectively, all being significantly higher than the age (6-10y) related controls (P< 0.01). In the 705 cerebral spinal fluid (CSF) specimens, VCA-IgG, VCA-IgM, VCA-IgA and EAD-IgA were found to be positive in 12.1%, 0.15%, 0.25% and 0.25%, respectively. There were 157 paired specimens (CSF and serum were collected simultaneously) and VCA-IgG was identified as positive in 12.7% of the CSF and 100% of the serum specimens. CONCLUSIONS: Around 98% of Chinese patients were infected with EBV before 30 years of age and the highest rate of acute EBV infection were observed in patients under 5 years old. EBV infection was found to be associated with elevated serum liver enzymes, NPC and SLE. Acute anti-EBV antibody was valued for young patients with lymphadenopathy but limited value for CNS neuropathy.

Positive Rate of Different Hepatitis B Virus Serological Markers in Peking Union Medical College Hospital, a General Tertiary Hospital in Beijing.

Objective s To investigate the positive rate of different hepatitis B virus (HBV) serological markers, and the demographic factors related to HBV infection.Methods We enrolled all patients tested for HBV serological markers, such as HBV surface antigen (HBsAg), HBV surface antibody (HBsAb), hepatitis B e antigen (HBeAg), hepatitis B e antibody (HBeAb), HBV core antibody (HBcAb), and HBV-DNA from July 2008 to July 2009 in Peking Union Medical College Hospital. The positive rate of each HBV serological marker was calculated according to gender, age, and de- partment, respectively. The positive rates of HBV-DNA among patients with positive HBsAg were also analyzed.Results Among 27 409 samples included, 2681 (9.8%) were HBsAg positive. When patients were divided into 9 age groups, the age-specific positive rate of HBsAg was 1.2%, 9.6%, 12.3%, 10.9%, 10.3%, 9.7%, 8.0%, 5.8%, and 4.3%, respectively. The positive rate of HBsAg in non-surgical department, surgical department, and health examination center was 16.2%,5.8%,and 4.7%, respectively. The positive rate of HBsAg of males (13.3%) was higher than that of females (7.3%, P=0.000). Among the 2681 HBsAg (+) patients, 1230 (45.9%) had HBV-DNA test, of whom 564 (45.9%) were positive. Patients with HBsAg (+), HBeAg (+), and HBcAg (+) result usually had high positive rate of HBV-DNA Results (71.8%, P=0.000).Conclusions Among this group of patients in our hospital, the positive rate of HBsAg was relatively high. Age group of 20-29, males, and patients in non-surgical departments were factors associated with high positive rate of HBsAg.

Seroprevalence of the Hepatitis B, Hepatitis C, and Human Immunodeficiency Viruses and Treponema pallidum at the Beijing General Hospital from 2010 to 2014: A Cross-Sectional Study.

BACKGROUND: The hepatitis B, hepatitis C, human immunodeficiency viruses and Treponema pallidum are important causes of infectious diseases concern to public health. METHODS: Between 2010 and 2014, we used an automated chemiluminescence microparticle immunoassay to detect the hepatitis B, hepatitis C, and human immunodeficiency viruses as well as Treponema pallidum (the rapid plasma regain test was used in 2010-2011). Positive human immunodeficiency virus tests were confirmed via western blotting. RESULTS: Among 416,130 subjects, the seroprevalences for hepatitis B virus, hepatitis C virus, human immunodeficiency virus, and Treponema pallidum were 5.72%, 1.23%, 0.196%, and 0.76%, respectively. Among 671 patients with positive human immunodeficiency virus results, 392 cases were confirmed via western blotting. Hepatitis B and human immunodeficiency virus infections were more frequent in men (7.78% and 0.26%, respectively) than in women (4.45% and 0.021%, respectively). The hepatitis B and C virus seroprevalences decreased from 6.21% and 1.58%, respectively, in 2010, to 5.37% and 0.988%, respectively, in 2014. The human immunodeficiency virus seroprevalence increased from 0.04% in 2010 to 0.17% in 2014, and was elevated in the Infectious Disease (2.65%), Emergency (1.71%), and Dermatology and Sexually Transmitted Diseases (1.12%) departments. The specificity of the human immunodeficiency virus screening was 71.4%. The false positive rates for the Treponema pallidum screening tests increased in patients who were 60-70 years old. The co-infection rates for the hepatitis C and human immunodeficiency viruses were 0.47% in hepatitis C virus-positive patients and 7.33% in human immunodeficiency virus-positive patients. CONCLUSIONS: During 2010-2014, hepatitis B virus and human immunodeficiency virus infections were more frequent among men at our institution. Although the seroprevalences of hepatitis B and C viruses decreased, the seroprevalence of human immunodeficiency virus infection increased (with higher seroprevalences in high-risk departments). Older patients were more likely to exhibit false positive findings for syphilis.