Mercury oxidation coupled to autotrophic denitrifying branched sulfur oxidation and sulfur disproportionation for simultaneous removal of Hg0 and NO.

Coupling elemental mercury (Hg0) oxidation, autotrophic denitrifying sulfur oxidation, and sulfur disproportionation offers technological potential for simultaneous Hg0 and nitric oxide (NO) removal. This study shed light on simultaneous demercuration and denitration of flue gas by a sulfur-oxidizing membrane biofilm reactor (MBfR). Removal efficiency of Hg0 and NO attained 92% and 83%, respectively in long-term operation. Taxonomic and metagenomic study revealed that a tremendous variety of Hg0-oxidizing bacteria (MOB) (Thiobacillus, Truepera, etc.), denitrifying/sulfur-oxidizing bacteria (DSOB) (Thioalkalivibrio, Thauera, etc.), sulfur-disproportionating bacteria (SDB) (Desulfobulbus, Desulfomicrobium, etc.), and multi-functional bacteria (Halothiobacillus, Thiobacillus, etc.) significantly increased in abundance during growth under feeding of Hg0 and NO in simulated flue gas. The comprehensive employment of sequential chemical extraction processes, inductive coupled mass spectrometry, X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy coupled to energy disperse spectroscopy confirmed that Hg0 was finally biologically oxidized to crystallized metacinnabar (ß-HgS) extracellular micromolecular particles. Our findings provided mechanistic insights that MOB, DSOB, and multi-functional bacteria synergistically bio-oxidized Hg0 as the initial electron donor to Hg2+ and denitrified NO as the terminal electron acceptor to N2. SDB disproportionated S0 branched from S2O32- into S2- and SO42-, and ß-HgS formation from Hg2+ and disproportionation-derived S2-, thermodynamically favored Hg0 bio-oxidation. This novel biotechnique can be a cost-effective and environmentally friendly alternative to flue gas Hg0 and NO treatment. KEY POINTS: • Combination of Hg0 bio-oxidation and autotrophic denitrifying sulfur oxidation achieved simultaneous Hg0 and NO removal. • Thiosulfate disproportionation reinforced Hg0 bio-oxidation for Hg0 removal. • Mercury-oxidizing bacteria, denitrifying/sulfur-oxidizing bacteria, and sulfur-disproportionating bacteria synergistically accomplished Hg0 and NO removal.

Labour patterns in Chinese women in Chongqing.

OBJECTIVE: To obtain data on the characteristics of labour from a regional sample of Chinese parturients and to assess the pattern of progress of labour among nulliparous women. DESIGN: A prospective observational study. SETTING: The study was conducted in the First Affiliated Hospital of Chongqing Medical University. POPULATION: The final sample involved 1200 Chinese parturients with singleton, vertex and term gestation; spontaneous onset of labour; vaginal delivery; and without adverse perinatal outcomes. METHODS: A repeated-measures analysis was used to depict labour curves while an interval-censored regression was used to estimate the duration of labour centimetre by centimetre. MAIN OUTCOME MEASURES: Labour curves and the duration of labour at the 50th and 95th percentiles. RESULTS: Among 1091 nulliparous women, 57.7% had cervical dilation of 3 cm or less at the time of admission, and the mean duration of the first stage of labour was 9.1 ± 3.3 hours. From 5 to 9 cm of cervical dilation it sometimes took more than 2 hours for dilation to advance 1 cm. No obvious inflection points appeared in the labour curve of Chinese nulliparae, and no deceleration was observed. CONCLUSION: Progress of labour in Chinese parturients was more gradual than in their Western counterparts. Obstetric practice standards based on data generated from Western countries may not be appropriate for Chinese women. TWEETABLE ABSTRACT: A prospective study has evaluated labour patterns in Chinese women using regional data from nulliparae.

The emergence of community-onset Clostridium difficile infection in a tertiary hospital in Singapore: a cause for concern.

Increasing rates of Clostridium difficile infection (CDI) among those without traditional risk factors have been reported mainly in Europe and North America. Here we describe the epidemiology, clinical features and ribotypes of CDI at National University Hospital (NUH), a 1000-bed tertiary care hospital in Singapore, from December 2011 to May 2012. All laboratory-confirmed CDI cases ≥21 years old who gave informed consent were included. Clinical data were collected prospectively and participants underwent an interviewer-administered questionnaire. Cases were classified by healthcare facility exposure and severity according to the SHEA guidelines. Included cases were also subjected to PCR and were classified by ribotype. In total, 66 patients participated in the study, of which 33 (50.0%) were healthcare-facility-associated hospital onset (HCFA-HO). Of the 33 community-onset (CO) cases, 14 (42.4%) were HCFA-CO, 10 (30.3%) were indeterminate and 9 (27.3%) were community-associated (CA). Of the CA cases, a majority (90.9%) had prior exposure to a healthcare facility within the last 12 weeks. Clinical characteristics, exposures and outcomes were not different between HO-CDI and CO-CDI. Diagnosis was delayed in CO-CDI compared with HO-CDI (4 days vs. 1 day; P=0.014). There was no difference in distribution of ribotypes between CO-CDI and HO-CDI, with 053 being most prevalent in both groups. CO-CDI increasingly contributes to the burden of CDI in NUH. This may reflect a trend in other parts of Asia. Healthcare professionals should be aware of the possible role of outpatient healthcare environments to CDI risk and thus extend control measures to outpatient settings.