[Epidemiological characteristics of a local cluster epidemic caused by the BA.2 evolutionary branch of Omicron variant].

Descriptive epidemiological methods were used to analyze the epidemiological characteristics of the local cluster of COVID-19 in the logistic park of Yuhang District in Hangzhou in March 2022. The cluster epidemic was detected by a case who actively visited the fever clinic. The epidemic lasted for 8 days, and a total of 58 cases (53 workers, 2 students, 1 farmer, 1 teacher and 1 unemployed) were found, including 40 males and 18 females. The age was (33.29±12.22) years. There cases were mainly in Yuhang District (48 cases, 82.77%) and Shangcheng District (7 cases, 12.07%) of Hangzhou. The real-time regeneration number peaked at 2.31 on March 10th and decreased to 0.37 on March 15th. The sequencing result of the indicated case was 100% homologous with the sequence uploaded from South Korea on March 4th, 2022.

[Characteristics and diversity of infectious diarrheal caused by various pathogens].

Objective: To understand the characteristics and differences of diarrhea-related symptoms caused by different pathogens, and the clinical features of various pathogens causing diarrhea. Methods: Etiology surveillance program was conducted among 20 provinces of China from 2010 to 2016. The acute diarrhea outpatients were collected from clinics or hospitals. A questionnaire was used to survey demographics and clinical features. VFeces samples were taken for laboratory detection of 22 common diarrhea pathogens, to detect and analyze the clinical symptom pattern characteristics of the patient's. Results: A total of 38 950 outpatients were enrolled from 20 provinces of China. The positive rates of Rotavirus and Norovirus were the highest among the five diarrhea-causing viruses (Rotavirus: 18.29%, Norovirus: 13.06%). In the isolation and culture of 17 diarrhea-causing bacterial, Escherichia coli showed the highest positive rates (6.25%). The clinical features of bacterial diarrhea and viral diarrhea were mainly reflected in the results of fecal traits and routine examination, but pathogenic Vibrio infection was similar to viral diarrhea. Conclusion: Infectious diarrhea presents different characteristics due to various symptoms which can provide a basis for clinical diagnosis.

Clinical and prognostic significance of protocadherin-10 (PCDH10) promoter methylation in bladder cancer.

OBJECTIVE: To investigate the clinical and prognostic significance of protocadherin-10 (PCDH10) promoter methylation in serum-derived DNA from patients with bladder cancer. METHODS: PCDH10 promoter methylation status was determined using methylation-specific polymerase chain reaction of DNA extracted from serum of patients with bladder cancer, and age- and sex-matched controls. Clinical and pathological details of bladder cancer were recorded. RESULTS: PCDH10 promoter methylation was detected in 59/117 (50.4%) of patients with bladder cancer, and none of 37 (0%) controls. Methylation was significantly associated with advanced stage (T(2)-T(4)), high grade (G(3)), tumour recurrence and larger tumour size (> 3 cm). In addition, methylation was associated with significantly worse survival and was an independent predictor of overall survival. CONCLUSION: Serum-based analysis of PCDH10 promoter methylation may represent a useful noninvasive biomarker of malignant behaviour and outcome in bladder cancer.

Calibrationless determination of creatinine and ammonia by coulometric flow titration.

A precise and sensitive working microflow titration procedure was developed to determine creatinine and ammonia in urine samples. This procedure is based on enzymatic conversion of creatinine, gas diffusional membrane separation of the released ammonia into an acid acceptor stream, and coulometric titration of ammonia with hypobromite. The hypobromite is formed after the electrogeneration of bromine in an electrolyte containing 1.0 M NaBr and 0.1 M sodium borate adjusted to pH 8.5. The electrolysis current follows a triangle-programmed current-time course. An amperometric flow detector records the resulting mirror symmetrical titration curves, which show two equivalence points. The analyte concentration is calculated from the time difference between the equivalence points. For quantitative conversion of creatinine and quantitative separation of present and released ammonia no calibration is necessary to get accurate results. Both ammonia/ammonium and creatinine were determined in the range between 2 microM and 2 mM with relative standard deviations between 3.0 and 1.0% (n = 5). High recoveries were obtained for the analysis of diluted urine samples for both creatinine and ammonia.

Precise and sensitive determination of nitrite by coulometric backtitration under flow conditions.

A novel method performing for coulometric backtitrations in flow channels was developed, which was applied for the precise and sensitive determination of low concentrations of nitrite. Under acid conditions nitrite is reacting stoichiometrically with hydrazine, the remained excess of which is backtitrated with electrogenerated bromine. The titration course is recorded either amperometrically or chemiluminometrically. Hydrazine can be determined precisely and accurately in the range between 0.1 microM and 1 mM without calibration. Nitrite is reduced by hydrazine according to the reaction 2 NO2- + 2 H+ + NH2-NH2 --> N2O + N2 + 3 H2O. Applying the amperometric and the chemiluminometric end-point location nitrite was determined accurately and precisely in the ranges 0.25-65 microM and 0.10-50 microM, respectively. The method was applied to the determination of nitrite in tap and river water.

Spectral studies on the interaction of DNA and Ru(bipy)2(dppx)2+.

The interaction of Ru(bipy)2(dppx)2+ (bipy = 2.2'-bipyridine,dppx = 7,8-dimethyldipyrido phenazine) with the calfthymus DNA has been studied with fluorescence and ultraviolet visible absorption spectroscopy. The results of fluorescence quenching and salt effect show that Ru(bipy)2(dppx)2+ intercalate into the double helix of DNA. The ultraviolet visible absorption spectrum of Ru(bipy)2(dppx)2+, calfthymus DNA, and their interaction indicate that Ru(bipy)2(dppx)2+ intercalate into the double helix of DNA via the ligand dppx.