For the existing measurement methods of residual voltage which can't turn the power off at peak voltage exactly and simultaneously display waveforms, a new residual voltage detection method is put forward in this paper. First, the zero point of the power supply is detected with zero cross detection circuit and is inputted to a single-chip microcomputer in the form of pulse signal. Secend, when the zero point delays to the peak voltage, the single-chip microcomputer sends control signal to power off the relay. At last, the waveform of the residual voltage is displayed on a principal computer or oscilloscope. The experimental results show that the device designed in this paper can turn the power off at peak voltage and is able to accurately display the voltage waveform immediately after power off and the standard deviation of the residual voltage is less than 0.2 V at exactly one second and later.
Electric Power Supplies ; Equipment Design ; Microcomputers ; Signal Processing, Computer-Assisted

Objective To improve theu nderstanding of the characteristci s of death in hospitail zed hc ildren and provide clinical cautionary information to professional healthcarep rovdie rs.Methods A retro-spective analysis was undertaken on thed ata of all children aged 1 month to 11 years who died at the Xinhua H ospital between 2007 and 2014.Demographic details,main causes of deaths,and chronic underyl ingd iseases were reviewed.Results Case fatality rate was 0.58%( 451/77 838 ) .Overall, the most common causes fo deathni hospitalized childer n were pneumo nia 38.80%(175/451),tumor 13.75%(62/451),sepsis 11.97%(54/451),central nerve system infection 8.00%(36/451) and accident 7.32%(33/451).Infectious disea-ses were the maoj r causes of deathi n children younger than 5ye ars of age(66.86%,230/344).In oc ntrast, noninfectious diseases accuo tn ed for mo re deathsni children more than 5 years old(52.34%,56/107).There were 343d eath cases comp licated wiht chronic undelr ying diseases.Congentia la bnormality was the most fre-quent chronic underlying disease observed in infants(59.90%,115/192) and tumor was the main chronic nu -derlying dsi easei not ddlers and elder children(34.36%,89/259).Conclusion Infectious diseasse were the major causes of deta hs,and teh mortality in the study popual tion decreased with age.Tumors and accidents accounted for more deaths in elder children.Chronic underlying diseases were found in most deaths of children.Efficient evaluation and effective intervention of these vulnerable children might save more lives.

ObjectiveTo study current status of benign breast diseases and metabolic syndrome in professional women in Chongqing and relative risk factors. MethodsProfessional women (2604 cases )in Chongqing were surveyed by random cluster sampling.The biochemical indicators such as blood lipid were determined by cholesterin oxidase.The indicators such as height and weight were measured by physical examination.Chi-square test and logistic regression were used in statistical analysis. Results The morbidity rate of benign breast diseases, metabolic syndrome, hyperglycaemia, hypertension, hyperlipidemia, and obesity in our study was 19.27％ (429/2226), 7.91％ ( 176/2226 ), 8.04％ ( 179/2226 ), 23.23％ ( 517/2226 ), 24.21％ ( 539/2226 ) and 20.5％ (457/2226) respectively.The difference of mobidity rate between different age group and different career had statistical significance.Office workers and civil servants were high risk population.Age was negatively correlated with benign breast diseases.There was no relation between benign breast diseases and metabolic syndrome.ConculsionsThe morbidity rate of benign breast diseases and metabolic symdrome in professional women in Chongqing is relatively high.A good lifestyle, breast self-examination and regular physicial examination are recommended.

Objective:To analyze the electrocardiographic characteristics of patients with chronic pulmonary artery stenosis (PAS), and to explore their relationship with disease severity indicators.Methods:The study was a retrospective case-series analysis. Patients with chronic PAS admitted to Gansu Provincial Hospital from January 2018 to July 2021 were enrolled. The clinical data and the results of electrocardiography, transthoracic echocardiography, right cardiac catheterization, N-terminal B-type natriuretic peptide (NT-proBNP) measurement and 6-min walking distance test of patients were analyzed. The linear regression model or logistic regression model was used to analyze the relationship between electrocardiographic characteristics and the disease severity in patients with chronic PAS.Results:Sixty-three patients aged (62.1±9.7) years including 43 females (68.3%) were enrolled in the study. Among them, 62 patients (98.4%) had (R 1+S Ⅲ)-(S Ⅰ+R Ⅲ)<1.5 mV, and no patients had V 5lead R: S ratio to V 1 lead R: S<0.04 and V 6 lead R: S ratio<0.4. There were 55 patients (87.3%), with flat or inverted T-waves in V 1, and 10 patients (15.9%) with flat or inverted T-waves in all precordial leads (V 1-V 6). There were 18 patients (28.6%) with flat or inverted T-waves in inferior leads (Ⅱ, Ⅲ, aVF). Multiple liner regression analysis showed that Max R V1, 2+Max S I, aVL-S V1 combined with the number of flat or inverted T-waves in limb leads was independently correlated with atrial area ( R2=0.290, P=0.002); R V1+S V5 was independently correlated with right ventricular area ( R2=0.257, P=0.001); R peak V 1 combined with the number of flat or inverted T waves in precordial leads was independently correlated with tricuspid annular plane systolic excursion ( R2=0.407, P<0.001); (R 1+S Ⅲ)-(S Ⅰ+R Ⅲ) combined with the number of flat or inverted T waves in precordial leads was independently correlated with NT-proBNP ( R2=0.504, P<0.001); Max R V1, 2+Max S I, aVL-S V1 were independently correlated with right atrial pressure ( R2=0.803, P=0.036); (R 1+S Ⅲ)-(S Ⅰ+R Ⅲ) were independently correlated with mean pulmonary artery pressure ( R2=0.302, P<0.001); R aVRcombined with the number of flat or inverted T-waves in precordial leads was independently correlated with cardiac index ( R2=0.173, P=0.003); (R 1+S Ⅲ)-(S Ⅰ+R Ⅲ) was independently correlated with pulmonary vascular resistance ( R2=0.173, P=0.002); R peak V 1 combined with the number of flat or inverted T-waves in precordial leads was independently correlated with mixed vein oxygen saturation ( R2=0.302, P<0.001). Conclusion:The vast majority of patients with chronic PAS have (R 1+S Ⅲ)-(S Ⅰ+R Ⅲ)<1.5 mV and flat or inverted T-wave in V 1 lead, and some characteristic electrocardiographic manifestations are correlated with indicators of disease severity.

BACKGROUNDBone damage around the joints is one of the major pathophysiological mechanisms that leads to rheumatoid arthritis (RA) chronic disability. Serum tartrate-resistant acid phosphatase 5b (TRACP-5b) is secreted by osteoclasts, its activity can be used as a clinically relevant bone resorption marker. The aim of this study was to test whether the measurement of serum levels of TRACP-5b in patients with RA would correlate with measures of disease activity and with responses to therapy.

METHODSFifty-six patients were randomly assigned to receive recombinant human cytotoxic tlymphocyte-associated antigen-4 immunoglobulin (RhCTLA4-Ig), infliximab or methotrexate (MTX). The clinical and serologic indicators of RA activity were evaluated at baseline and at 24 weeks. Serum TRACP-5b was measured by Enzyme-linked Immunosorbent Assay (ELISA) at 0, 12 and 24 weeks. Hand X-rays were obtained at baseline.

RESULTSAt baseline, the levels of TRACP-5b correlated with the severity of X-ray damage, disease duration (r = 0.332, P = 0.012), and tender joint count (r = 0.408, P = 0.002). The 24 weeks values of TRACP-5b for RhCTLA4-Ig group and infliximab group differed significantly from the baseline values in each group (P < 0.05; P < 0.05), whereas only the value for RhCTLA4-Ig group differed significantly from the 24 weeks value for the MTX group (P < 0.01). Considering the two biologics-treated groups together, the TRACP-5b levels at 24 weeks differed significantly from the baseline values only in those patients who reached an ACR70 level (P < 0.05).

CONCLUSIONSMeasurement of serum TRACP-5b in RA patients reflects clinical and radiological measures of disease activity, treatment with certain biologics, and degree of response to therapy. TRACP-5b should be investigated further as a potential biomarker to predict response to therapy, including slowing of radiographic progression.

Acid Phosphatase ; blood ; Adolescent ; Adult ; Antibodies, Monoclonal ; therapeutic use ; Arthritis, Rheumatoid ; blood ; drug therapy ; Biomarkers ; blood ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Infliximab ; Isoenzymes ; blood ; Male ; Methotrexate ; therapeutic use ; Middle Aged ; Osteoclasts ; metabolism ; Pilot Projects ; Tartrate-Resistant Acid Phosphatase ; Young Adult

Objective To understand the distribution of novel coronaviruses in the external environment of confirmed COVID-19 cases. Methods Environmental surface swab specimens such as bed rails, doorknob, closestool, hand washing sink, table, locker,ward pager, mobile phone, cup, clothes, were collected from the sentinel hospital of COVID-19, and samples were collected for the nucleic acid detection by RT-PCR. Results A total of 150 environmental samples were collected from 30 confirmed COVID-19 cases, 6 samples were determined to be novel coronaviruses postive (positive rate 4.00%). The total 14 mobile phone showed 3 novel coronaviruses positive.Among the 30 confirmed COVID-19 cases, 6 cases (positive rate 20.00%)were found novel coronaviruses in the external environment. Conclusions Novel coronaviruses exists in external environment of confirmed COVID-19 cases, which indicates the potential risk of COVID-19 infection.