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Uranium–35 wt.% zirconium (U–35 wt.% Zr) alloy was annealed for 1 h and 24 h at 650 °C and characterized to understand the early-stage microstructure evolution. Dendritic microstructure with fine (∼300 nm in length) α-U precipitates clustered between dendrite branches were observed in the 1-h annealed sample. After 24-h annealing at 650 °C, the α-U precipitates coarsened, and the dendritic microstructure disappeared because of microstructure homogenization. Furthermore, microchemical homogenization observed with energy-dispersive X-ray spectroscopy analysis suggests that α-U precipitates are approaching thermodynamic equilibrium in the 24-h annealed sample. The findings from this study have potential impacts on the manufacturing and computer modeling of metallic nuclear fuel.
Enteric illness outbreaks are complex events, therefore, outbreak investigators use many different hypothesis generation methods depending on the situation. This scoping review was conducted to describe methods used to generate a hypothesis during enteric illness outbreak investigations. The search included five databases and grey literature for articles published between 1 January 2000 and 2 May 2015. Relevance screening and article characterisation were conducted by two independent reviewers using pretested forms. There were 903 outbreaks that described hypothesis generation methods and 33 papers which focused on the evaluation of hypothesis generation methods. Common hypothesis generation methods described are analytic studies (64.8%), descriptive epidemiology (33.7%), food or environmental sampling (32.8%) and facility inspections (27.9%). The least common methods included the use of a single interviewer (0.4%) and investigation of outliers (0.4%). Most studies reported using two or more methods to generate hypotheses (81.2%), with 29.2% of studies reporting using four or more. The use of multiple different hypothesis generation methods both within and between outbreaks highlights the complexity of enteric illness outbreak investigations. Future research should examine the effectiveness of each method and the contexts for which each is most effective in efficiently leading to source identification.
Rabies is one of the major public health problems in China, and the mortality rate of rabies remains the highest among all notifiable infectious diseases. A meta-analysis was conducted to investigate the post-exposure prophylaxis (PEP) vaccination rate and risk factors for human rabies in mainland China. The PubMed, Web of Science, Chinese National Knowledge Infrastructure, Chinese Science and Technology Periodical and Wanfang databases were searched for articles on rabies vaccination status (published between 2007 and 2017). In total, 10 174 human rabies cases from 136 studies were included in this meta-analysis. Approximately 97.2% (95% confidence interval (CI) 95.1–98.7%) of rabies cases occurred in rural areas and 72.6% (95% CI 70.0–75.1%) occurred in farmers. Overall, the vaccination rate in the reported human rabies cases was 15.4% (95% CI 13.7–17.4%). However, among vaccinated individuals, 85.5% (95% CI 79.8%–83.4%) did not complete the vaccination regimen. In a subgroup analysis, the PEP vaccination rate in the eastern region (18.8%, 95% CI 15.9–22.1%) was higher than that in the western region (13.3%, 95% CI 11.1–15.8%) and this rate decreased after 2007. Approximately 68.9% (95% CI 63.6–73.8%) of rabies cases experienced category-III exposures, but their PEP vaccination rate was 27.0% (95% CI 14.4–44.9%) and only 6.1% (95% CI 4.4–8.4%) received rabies immunoglobulin. Together, these results suggested that the PEP vaccination rate among human rabies cases was low in mainland China. Therefore, standardised treatment and vaccination programs of dog bites need to be further strengthened, particularly in rural areas.
Our objective was to identify predictors of severe acute respiratory infection in hospitalised patients and understand the impact of vaccination and neuraminidase inhibitor administration on severe influenza. We analysed data from a study evaluating influenza vaccine effectiveness in two Michigan hospitals during the 2014–2015 and 2015–2016 influenza seasons. Adults admitted to the hospital with an acute respiratory infection were eligible. Through patient interview and medical record review, we evaluated potential risk factors for severe disease, defined as ICU admission, 30-day readmission, and hospital length of stay (LOS). Two hundred sixteen of 1119 participants had PCR-confirmed influenza. Frailty score, Charlson score and tertile of prior-year healthcare visits were associated with LOS. Charlson score >2 (OR 1.5 (1.0–2.3)) was associated with ICU admission. Highest tertile of prior-year visits (OR 0.3 (0.2–0.7)) was associated with decreased ICU admission. Increasing tertile of visits (OR 1.5 (1.2–1.8)) was associated with 30-day readmission. Frailty and prior-year healthcare visits were associated with 30-day readmission among influenza-positive participants. Neuraminidase inhibitors were associated with decreased LOS among vaccinated participants with influenza A (HR 1.6 (1.0–2.4)). Overall, frailty and lack of prior-year healthcare visits were predictors of disease severity. Neuraminidase inhibitors were associated with reduced severity among vaccine recipients.
Introduction: Survival from cardiac arrest has been linked to the quality of resuscitation care. Unfortunately, healthcare providers frequently underperform in these critical scenarios, with a well-documented deterioration in skills weeks to months following advanced life support courses. Improving initial training and preventing decay in knowledge and skills are a priority in resuscitation education. The spacing effect has repeatedly been shown to have an impact on learning and retention. Despite its potential advantages, the spacing effect has seldom been applied to organized education training or complex motor skill learning where it has the potential to make a significant impact. The purpose of this study was to determine if a resuscitation course taught in a spaced format compared to the usual massed instruction results in improved retention of procedural skills. Methods: EMS providers (Paramedics and Emergency Medical Technicians (EMT)) were block randomized to receive a Pediatric Advanced Life Support (PALS) course in either a spaced format (four 210-minute weekly sessions) or a massed format (two sequential 7-hour days). Blinded observers used expert-developed 4-point global rating scales to assess video recordings of each learner performing various resuscitation skills before, after and 3-months following course completion. Primary outcomes were performance on infant bag-valve-mask ventilation (BVMV), intraosseous (IO) insertion, infant intubation, infant and adult chest compressions. Results: Forty-eight of 50 participants completed the study protocol (26 spaced and 22 massed). There was no significant difference between the two groups on testing before and immediately after the course. 3-months following course completion participants in the spaced cohort scored higher overall for BVMV (2.2 ± 0.13 versus 1.8 ± 0.14, p=0.012) without statistically significant difference in scores for IO insertion (3.0 ± 0.13 versus 2.7± 0.13, p= 0.052), intubation (2.7± 0.13 versus 2.5 ± 0.14, p=0.249), infant compressions (2.5± 0.28 versus 2.5± 0.31, p=0.831) and adult compressions (2.3± 0.24 versus 2.2± 0.26, p=0.728) Conclusion: Procedural skills taught in a spaced format result in at least as good learning as the traditional massed format; more complex skills taught in a spaced format may result in better long term retention when compared to traditional massed training as there was a clear difference in BVMV and trend toward a difference in IO insertion.
Central line-associated bloodstream infections (CLABSIs) in intensive care units (ICUs) result in poor clinical outcomes and increased costs. Although frequently regarded as preventable, infection risk may be influenced by non-modifiable factors. The objectives of this study were to evaluate organisational factors associated with CLABSI in Victorian ICUs to determine the nature and relative contribution of modifiable and non-modifiable risk factors. Data captured by the Australian and New Zealand Intensive Care Society regarding ICU-admitted patients and resources were linked to CLABSI surveillance data collated by the Victorian Healthcare Associated Infection Surveillance System between 1 January 2010 and 31 December 2013. Accepted CLABSI surveillance methods were applied and hospital/patient characteristics were classified as ‘modifiable’ and ‘non-modifiable’, enabling longitudinal Poisson regression modelling of CLABSI risk. In total, 26 ICUs were studied. Annual CLABSI rates were 1·72, 1·37, 1·00 and 0·93/1000 CVC days for 2010–2013. Of non-modifiable factors, the number of non-invasively ventilated patients standardised to total ICU bed days was found to be independently associated with infection (RR 1·07; 95% CI 1·01–1·13; P = 0·030). Modelling of modifiable risk factors demonstrated the existence of a policy for mandatory ultrasound guidance for central venous catheter (CVC) localisation (RR 0·51; 95% CI 0·37–0·70; P < 0·001) and increased number of sessional specialist full-time equivalents (RR 0·52; 95% CI 0·29–0·93; P = 0·027) to be independently associated with protection against infection. Modifiable factors associated with reduced CLABSI risk include ultrasound guidance for CVC localisation and increased availability of sessional medical specialists.
As an epigenetic modification, DNA methylation may reflect the interaction between genetic and environmental factors in the development of schizophrenia (SCZ). Catechol-O-methyltransferase (COMT) gene is a promising candidate gene of SCZ. In the present study, we investigate the association of COMT methylation with the risk of SCZ using bisulfite pyrosequencing technology. Significant association between DNA methylation of COMT and the risk of SCZ is identified (P = 1.618e−007). A breakdown analysis by gender shows that the significance is driven by males (P = 3.310e−009), but not by females. DNA methylation of COMT is not significantly associated with SCZ clinical phenotypes, including p300 and cysteine level. No interaction is found between COMT genotypes and the percent methylation of this gene. Receiver operating characteristic (ROC) curve shows that DNA methylation of COMT is able to predict the SCZ risk in males (area under curve [AUC] = 0.802, P = 1.91e−007). The current study indicates the clinical value of COMT methylation as a potential male-specific biomarker in SCZ diagnosis.
There are two marine species in the genus Ozobranchus. Ozobranchus branchiatus mainly parasitizes green turtles and O. margoi parasitizes most turtle species. We used sequences for the mitochondrial cytochrome c oxidase subunit I gene (COI sequence analysis), along with morphological diagnosis, to compare the population genetic structures of O. branchiatus and O. margoi collected near Taiwan to those of their populations in the Atlantic. The results provide estimates of the genetic divergence between these leeches in the two regions. Ozobranchus branchiatus had a greater pairwise distance within Taiwan (0.0031–0.0141) than O. margoi (no differences). Phylogenetic tree analysis identified one O. branchiatus clade and one O. margoi clade in Taiwan. The better environmental adaptability and lower host specificity of O. margoi might result in lower genetic divergence among populations.
To evaluate the effect of pre- and post-admission antibiotic treatment in paediatric acute mastoiditis.
Eighty-eight children with acute mastoiditis, from 2003 to 2012, were studied to investigate the effect of antibiotic therapy on short and long-term sequelae.
The median period of antibiotic therapy immediately following hospital discharge was 10 days (range, 5–49 days; standard deviation = 7.46). There were no sequelae within the fortnight following antibiotic therapy completion, but 14 of 40 patients had significant sequelae thereafter, including recurrent otorrhoea, acute otitis media and ventilation tube insertion requirement. Complication rates were significantly higher among patients who had pre-admission antibiotic therapy (52 per cent), compared to patients previously untreated (27 per cent).
Paediatric acute mastoiditis patients treated with antibiotic therapy prior to admission are at higher risk for complication development. The advised time period for oral antibiotic therapy following hospital discharge remains as 10 days in all cases of uncomplicated acute mastoiditis.
We describe the performance of the Boolardy Engineering Test Array, the prototype for the Australian Square Kilometre Array Pathfinder telescope. Boolardy Engineering Test Array is the first aperture synthesis radio telescope to use phased array feed technology, giving it the ability to electronically form up to nine dual-polarisation beams. We report the methods developed for forming and measuring the beams, and the adaptations that have been made to the traditional calibration and imaging procedures in order to allow BETA to function as a multi-beam aperture synthesis telescope. We describe the commissioning of the instrument and present details of Boolardy Engineering Test Array’s performance: sensitivity, beam characteristics, polarimetric properties, and image quality. We summarise the astronomical science that it has produced and draw lessons from operating Boolardy Engineering Test Array that will be relevant to the commissioning and operation of the final Australian Square Kilometre Array Path telescope.
The genetic influences in human brain structure and function and impaired functional connectivities are the hallmarks of the schizophrenic brain. To explore how common genetic variants affect the connectivities in schizophrenia, we applied genome-wide association studies assaying the abnormal neural connectivities in schizophrenia as quantitative traits.
We recruited 161 first-onset and treatment-naive patients with schizophrenia and 150 healthy controls. All the participants underwent scanning with a 3 T-magnetic resonance imaging scanner to acquire structural and functional imaging data and genotyping using the HumanOmniZhongHua-8 BeadChip. The brain-wide association study approach was employed to account for the inherent modular nature of brain connectivities.
We found differences in four abnormal functional connectivities [left rectus to left thalamus (REC.L–THA.L), left rectus to right thalamus (REC.L–THA.R), left superior orbital cortex to left thalamus (ORBsup.L–THA.L) and left superior orbital cortex to right thalamus (ORBsup.L–THA.R)] between the two groups. Univariate single nucleotide polymorphism (SNP)-based association revealed that the SNP rs6800381, located nearest to the CHRM3 (cholinergic receptor, muscarinic 3) gene, reached genomic significance (p = 1.768 × 10−8) using REC.L–THA.R as the phenotype. Multivariate gene-based association revealed that the FAM12A (family with sequence similarity 12, member A) gene nearly reached genomic significance (nominal p = 2.22 × 10–6, corrected p = 0.05).
Overall, we identified the first evidence that the CHRM3 gene plays a role in abnormal thalamo-orbital frontal cortex functional connectivity in first-episode treatment-naive patients with schizophrenia. Identification of these genetic variants using neuroimaging genetics provides insights into the causes of variability in human brain development, and may help us determine the mechanisms of dysfunction in schizophrenia.
The thermal shock resistance (TSR) of ZnS wave-transparent ceramic depends on not only the mechanical and thermal properties of materials, but also the aerodynamic heating, pneumatic pressure, external constraint, size, aspect ratio and other factors in its actual service process. The theoretical model was established by introducing the analytical solution of transient heat conduction problem of ZnS plate under aerodynamic heating into its thermal stress field model and the pneumatic pressure was introduced. The present work mainly focused on the influences of constraint, size and aspect ratio on the critical rupture temperature difference of ZnS plate subjected to aerodynamic heating and pneumatic pressure. The numerical simulation was also conducted to verify the theoretical model. The results show that the large heat transfer condition corresponds to the poor TSR unless the constraint is too strong; the square plate provides the better TSR in case of different pneumatic pressures; a reasonable side length according to the range of pneumatic pressure would lead to the better TSR.
We determined the prevalence and seasonality of infections by Fasciola of goats and bovine species (cattle and water buffalo) in Hubei and Anhui provinces of China. Faecal samples were collected at 2- to 3-month intervals from 200 goats in Hubei province and from 152 bovine species in Anhui province. All faecal samples were examined for the presence of parasites. We determined the nucleotide sequences of the first and second internal transcribed spacers (ITS-1 and ITS-2) of the nuclear ribosomal DNA (rDNA) of 39 Fasciola worms from Anhui province. The prevalence of Fasciola infection in goats ranged between 3.5 and 37.0%, with mean eggs per gram (EPG) ranging between 29.0 and 166.0. Prevalence and EPG exhibited downward trends over time with significant differences. The prevalence of Fasciola infection in cattle ranged between 13.3 and 46.2% (mean EPG, 36.4–100.0), and that of water buffalo ranged between 10.3 and 35.4% (mean EPG, 25.0–89.6), with a higher prevalence of infection and EPG from June to October compared with December to March. Analysis of ITS-1 and ITS-2 sequences revealed that F. hepatica and F. gigantica were present in all bovine species of Anhui province and that F. gigantica mainly infected water buffalo. This is the first demonstration of Fasciola infection in Hubei province and detection of F. hepatica and F. gigantica in Anhui province. The present study of Hubei province shows that mass treatment of livestock with closantel sodium injections in April and August/September controlled Fasciola infection effectively.