•The cyclic behavior of the corrugated steel plate (CSP) link was tested and validated.•The corrugation can provide adequate out-of-plane support to the steel plate.•The effect of geometric ...parameters on the seismic behavior of CSP was investigated.•Finite element simulation with ABAQUS can reliably predict CSP’s nonlinear behavior.•The proposed simplified equations can effectively predict the capacity of CSP.
In this paper, a novel replaceable corrugated steel plate (CSP) link is proposed. Eleven specimens with different geometries were tested. The results show that the yield lateral load and initial stiffness of the specimen were mainly affected by the aspect ratio of the CSP. On the other hand, the peak lateral load, ductility, and energy dissipation were closely related to the depth and aspect ratios of the corrugation. Robust finite element models were built to simulate the hysteretic behavior of the CSP. The result shows the finite element models were capable of simulating the cyclic response of CSP well. To facilitate design efficiency, simplified equations were proposed to predict the yield lateral load, peak lateral load, and initial stiffness of the CSP. The results show that these equations can be used efficiently to predict the capacity of CSP. Overall, this study provides a comprehensive experimental and analytical study to show that the proposed CSP link has stable seismic performance and can be used as an effective steel link for seismic applications.
Summary Background Routine surveillance in a neonatal intensive care unit (NICU) showed an increased detection of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (ESBL- E. coli ) in ...August 2012, following nearly a year without detection. Aim To describe the investigation and interventions by a hospital infection control team of an outbreak of ESBL- E. coli in a NICU. Methods Six neonates with positive cultures of ESBL- E. coli (five with respiratory colonization, one with a urinary tract infection), control infants who were negative for ESBL- E. coli during the study period, and mothers who donated their breast milk were included. A case–control study was performed to identify possible risk factors for positive ESBL- E. coli cultures and molecular typing of isolated strains by pulsed-field gel electrophoresis. Findings The odds ratio for ESBL- E. coli infection after receiving shared unpasteurized breast milk during the study period was 49.17 (95% confidence interval: 6.02–354.68; P < 0.05). The pulsed-field gel electrophoresis pattern showed that all strains were identical, and the same pathogen was detected in freshly expressed milk of a particular donor. After ceasing the breast milk sharing, the outbreak was successfully terminated. Conclusion This outbreak indicates that contamination of milk packs can result in transmission of a drug-resistant pathogen to newborn infants. Providers of human breast milk need to be aware of the necessity for low-temperature pasteurization and bacterial cultures, which should be conducted before and after freezing, before prescribing to infants.
Localized infrared (IR) laser heating of fused silica optics has proven highly effective in reducing or removing surface flaws, which tend to limit performance in high power laser systems. Here, we ...present both simulation and experimental results to examine the use of IR laser light to polish, anneal, and micro‐shape fused silica surfaces used in high power laser systems. We show how the resulting material response can be tuned by considering the temperature‐dependent optical constants of the material and choosing the appropriate laser parameter set. For example, non‐evaporative laser polishing of glass surfaces to heal crack networks is shown most effective when using mid‐IR lasers, which lead to laser energy coupling up to ≈1 mm in depth. In contrast, long‐wave IR light tuned to the Restrahlen frequency of the material is shown to evaporate material most efficiently with penetration depths of <1 μm. Through calibrated, time‐resolved thermal imaging we are able to monitor the laser polishing process, to control material response. The results of our studies can be applied beyond the practical application of damage mitigation in high energy pulsed laser systems to any which require laser‐smoothing and shaping of silica surfaces.
Localized infrared laser heating can effectively remove surface flaws, which limit performance in high power laser systems. Through direct thermal imaging and finite element modeling, we show how flaw repair can be achieved through thermal annealing or micro‐machining methods. The wavelength‐dependent optical constants and thermal diffusion time of the material are shown to be crucial in optimizing laser parameters.
The 12-item Chinese Health Questionnaire (CHQ-12) has been widely used for screening mental disorders. This study aims to examine the internal consistency and factor structure of CHQ-12 and its ...suitability for use in the elderly Chinese population.
This is a cross-sectional study.
A total of 8526 elderly people aged ≥60 years from 11 cities in Shanxi Province were selected for participation in this study by stratified random cluster sampling. Cronbach’s alpha was employed to assess internal consistency. An exploratory factor analysis (EFA) was performed to explore the underlying factor structure of the CHQ-12 in the elderly. A confirmatory factor analysis (CFA) was then conducted to test and compare the goodness-of-fit between possible factor structure obtained from the EFA and the unidimensional structure, which was originally recommended.
The Cronbach’s alpha for CHQ-12 was 0.838. The EFA extracted three factors, which explained 55.985% of the total variance of the data. The CFA of the three-factor model resulted in an acceptable model fit (Comparative Fit Index = 0.98, Tucker–Lewis Index = 0.97, Normed Fit Index = 0.98, Expected Cross-Validation Index = 0.28, Root-Mean-Square Error of Approximation = 0.071). The item loadings ranged from 0.58 to 0.82. Correlation coefficients among the three factors ranged from 0.40 to 0.75.
The CHQ-12 presented satisfactory internal consistency and structural validity in the Chinese elderly population. The CFA of the three-factor structure expressed a preferred model fit in comparison to the unidimensional model. The three-factor structure of the CHQ-12 interpreted three different aspects of mental health: somatic symptoms, anxiety and worry, and depression/poor family relationship.
•First study to explore the factor structure of CHQ-12 in a large sample of the elderly Chinese population.•CHQ-12 had satisfactory internal consistency and structural validity among the elderly population.•Exploratory factor analysis generated three factors - somatic symptoms, anxiety, and depression/poor family relationship.•The three-factor structure of CHQ-12 showed the preferred fit to the data in comparison to the unidimensional model.
Major depressive disorder (MDD) often emerges during adolescence, a critical period of brain development. Recent resting-state fMRI studies of adults suggest that MDD is associated with abnormalities ...within and between resting-state networks (RSNs). Here we tested whether adolescent MDD is characterized by abnormalities in interactions among RSNs. Participants were 55 unmedicated adolescents diagnosed with MDD and 56 matched healthy controls. Functional connectivity was mapped using resting-state fMRI. We used the network-based statistic (NBS) to compare large-scale connectivity between groups and also compared the groups on graph metrics. We further assessed whether group differences identified using nodes defined from functionally defined RSNs were also evident when using anatomically defined nodes. In addition, we examined relations between network abnormalities and depression severity and duration. Finally, we compared intranetwork connectivity between groups and assessed the replication of previously reported MDD-related abnormalities in connectivity. The NBS indicated that, compared with controls, depressed adolescents exhibited reduced connectivity (p<0.024, corrected) between a specific set of RSNs, including components of the attention, central executive, salience, and default mode networks. The NBS did not identify group differences in network connectivity when using anatomically defined nodes. Longer duration of depression was significantly correlated with reduced connectivity in this set of network interactions (p=0.020, corrected), specifically with reduced connectivity between components of the dorsal attention network. The dorsal attention network was also characterized by reduced intranetwork connectivity in the MDD group. Finally, we replicated previously reported abnormal connectivity in individuals with MDD. In summary, adolescents with MDD show hypoconnectivity between large-scale brain networks compared with healthy controls. Given that connectivity among these networks typically increases during adolescent neurodevelopment, these results suggest that adolescent depression is associated with abnormalities in neural systems that are still developing during this critical period.
We present a detailed description of a new hadronic multiparticle production model for use in neutrino interaction simulations. Its validity spans a wide invariant mass range starting from the pion ...production threshold. This model focuses on the low invariant mass region which is probed in few-GeV neutrino interactions and is of particular importance to neutrino oscillation experiments using accelerator and atmospheric fluxes. It exhibits reasonable agreement with a wide variety of experimental data. We also describe measurements that can be made in upcoming experiments that can improve modeling in areas where uncertainties are currently large.
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