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This SHEA white paper identifies knowledge gaps and challenges in healthcare epidemiology research related to coronavirus disease 2019 (COVID-19) with a focus on core principles of healthcare epidemiology. These gaps, revealed during the worst phases of the COVID-19 pandemic, are described in 10 sections: epidemiology, outbreak investigation, surveillance, isolation precaution practices, personal protective equipment (PPE), environmental contamination and disinfection, drug and supply shortages, antimicrobial stewardship, healthcare personnel (HCP) occupational safety, and return to work policies. Each section highlights three critical healthcare epidemiology research questions with detailed description provided in supplementary materials. This research agenda calls for translational studies from laboratory-based basic science research to well-designed, large-scale studies and health outcomes research. Research gaps and challenges related to nursing homes and social disparities are included. Collaborations across various disciplines, expertise and across diverse geographic locations will be critical.
We aimed to investigate the heterogeneity of seasonal suicide patterns among multiple geographically, demographically and socioeconomically diverse populations.
Weekly time-series data of suicide counts for 354 communities in 12 countries during 1986–2016 were analysed. Two-stage analysis was performed. In the first stage, a generalised linear model, including cyclic splines, was used to estimate seasonal patterns of suicide for each community. In the second stage, the community-specific seasonal patterns were combined for each country using meta-regression. In addition, the community-specific seasonal patterns were regressed onto community-level socioeconomic, demographic and environmental indicators using meta-regression.
We observed seasonal patterns in suicide, with the counts peaking in spring and declining to a trough in winter in most of the countries. However, the shape of seasonal patterns varied among countries from bimodal to unimodal seasonality. The amplitude of seasonal patterns (i.e. the peak/trough relative risk) also varied from 1.47 (95% confidence interval [CI]: 1.33–1.62) to 1.05 (95% CI: 1.01–1.1) among 12 countries. The subgroup difference in the seasonal pattern also varied over countries. In some countries, larger amplitude was shown for females and for the elderly population (≥65 years of age) than for males and for younger people, respectively. The subperiod difference also varied; some countries showed increasing seasonality while others showed a decrease or little change. Finally, the amplitude was larger for communities with colder climates, higher proportions of elderly people and lower unemployment rates (p-values < 0.05).
Despite the common features of a spring peak and a winter trough, seasonal suicide patterns were largely heterogeneous in shape, amplitude, subgroup differences and temporal changes among different populations, as influenced by climate, demographic and socioeconomic conditions. Our findings may help elucidate the underlying mechanisms of seasonal suicide patterns and aid in improving the design of population-specific suicide prevention programmes based on these patterns.
Korea has the highest suicide rate of developed countries, two times higher than the USA. Suicide trends among Koreans Americans living in the USA during the same period have not yet been described. We report suicide mortality rates and trends for four groups: (1) Korean Americans, (2) non-Hispanic White (NHW) Americans, (3) selected Asian American subgroups and (4) Koreans living in the Republic of Korea.
We used US national (n = 18 113 585) and World Health Organization (WHO) (n = 232 919 253) mortality records for Korea from 2003 to 2012 to calculate suicide rates, all expressed per 100 000 persons. We assessed temporal trends and differences in age, gender and race/ethnicity using binomial regression.
Suicide rates are highest in Koreans living in the Republic of Korea (32.4 for men and 14.8 for women). Suicide rates in Korean Americans (13.9 for men and 6.5 for women) have nearly doubled from 2003 to 2012 and exceed rates for all other Asian American subgroups (5.4–10.7 for men and 1.6–4.2 for women). Suicide rates among NHWs (21.0 for men and 5.6 for women) remain high. Among elders, suicide in Korean Americans (32.9 for men and 15.4 for women) is the highest of all examined racial/ethnic groups in the USA.
Suicide in Korean Americans is higher than for other Asian Americans and follows temporal patterns more similar to Korea than the USA. Interventions to prevent suicide in Korean American populations, particularly among the elderly, are needed.
An association between low levels of physical activity and impaired cognitive performance in schizophrenia has been proposed, but most studies have relied on self-report measures of activity. This study examined the association between actigraphy-derived physical activity and cognitive performance adjusting for multiple covariates in patients with schizophrenia.
Patients with schizophrenia (n = 199) were recruited from chronic psychiatric wards, and 60 age-, sex- and body mass index-matched comparison participants were recruited from the staff of two hospitals and universities. Physical activity was assessed objectively for 7 days using an ActiGraph. Cognitive performance was assessed with the Cognitrone test from the Vienna Test System and the Grooved Pegboard Test. Demographic variables, metabolic parameters, positive and negative symptoms, duration of illness and hospitalization, and medication use were included as covariates. Pearson correlations and multivariable linear regressions were conducted to examine the associations between physical activity levels and cognitive performance.
Patients with schizophrenia were less physically active and had poorer performance on attention/concentration and speed of processing than the comparison group. Patients with schizophrenia who spent more time in light physical activity showed better performance on attention/concentration (β = 0.198, p = 0.020) and speed of processing (β= −0.169, p = 0.048) tasks than those who were less active. Cognitive performance was also associated with moderate-vigorous physical activity, but the effect was no longer significant once light physical activity had been taken into account.
This study provides evidence for a positive association between objectively measured light physical activity and cognitive performance in people with schizophrenia, after adjustment for multiple confounders.
Bitter gourd (Momordica charantia L.) is an important market vegetable in the tropics. The objectives of this study were to (1) conduct a preliminary evaluation of genetic diversity in bitter gourd flesh (without seeds) for phytonutrient (carotenoid, ascorbic acid and tocopherol) contents with the aim to understand which phytonutrients might be increased through breeding, (2) assess the association between fruit traits and phytonutrient contents and (3) evaluate the effect of the fruit harvest stage on phytonutrient contents. A total of 17 diverse bitter gourd entries of various commercial market types were evaluated for fruit traits and phytonutrient contents for 2 years. Significant differences (P= 0.05) among the entries were detected for total carotenoids, total tocopherols, dry matter and fruit traits. Mean total carotenoid contents of the entries ranged from 10 to 1335 μg/100 g fresh weight in year 1 and 10 to 1185 μg/100 g fresh weight in year 2. Mean ascorbic acid contents were 69 and 61 mg/100 g fresh weight in year 1 and year 2, respectively. Total tocopherol contents among the entries ranged from 480 to 1345 and 445 to 2145 μg/100 g fresh weight in year 1 and year 2, respectively. Total carotenoid and ascorbic acid contents were highest at 12 days after fruit set (DAFS), but total tocopherol contents were highest from 14 to 20 DAFS. A 100 g portion of bitter gourd fruit can meet 190, 17 and 8% of the recommended daily allowances of vitamin C, vitamin E and vitamin A, respectively, for adults.
Language use is often disrupted in patients with schizophrenia; novel
computational approaches may provide new insights.
To test word use patterns as markers of the perceptual, cognitive and
social experiences characteristic of schizophrenia.
Word counting software was applied to first-person accounts of
schizophrenia and mood disorder.
More third-person plural pronouns (‘they’) and fewer first-person
singular pronouns (‘I’) were used in schizophrenia than mood disorder
accounts. Schizophrenia accounts included fewer words related to the body
and ingestion, and more related to religion. Perceptual and causal
language were negatively correlated in schizophrenia accounts but
positively correlated in mood disorder accounts.
Differences in pronouns suggest decreased self-focus or perhaps even an
understanding of self as other in schizophrenia. Differences in how
perceptual and causal words are correlated suggest that long-held
delusions represent a decreased coupling of explanations with sensory
experience over time.
This paper describes the system architecture of a newly constructed radio telescope – the Boolardy engineering test array, which is a prototype of the Australian square kilometre array pathfinder telescope. Phased array feed technology is used to form multiple simultaneous beams per antenna, providing astronomers with unprecedented survey speed. The test array described here is a six-antenna interferometer, fitted with prototype signal processing hardware capable of forming at least nine dual-polarisation beams simultaneously, allowing several square degrees to be imaged in a single pointed observation. The main purpose of the test array is to develop beamforming and wide-field calibration methods for use with the full telescope, but it will also be capable of limited early science demonstrations.
To determine whether controlling the prescription of targeted antibiotics would translate to a measurable reduction in hospital-onset Clostridium difficile infection (CDI) rates.
A multicenter before-and-after intervention comparative study.
Ten medical centers in the greater New York region. Intervention group comprised of 6 facilities with early antimicrobial stewardship programs (ASPs). The 4 facilities without ASPs made up the nonintervention group.
Intervention facilities identified target antibiotics using case-control studies and implemented ASP-based strategies to control their use. Pre- and postintervention hospital-onset CDI rates and antibiotic consumption were compared for a 20-month period from June 2010 to January 2012. Antibiotic usage was compared using defined daily dose, days of therapy, and number of courses prescribed. Comparisons used bivariate and regression techniques.
Intervention facilities identified piperacillin/tazobactam, fluoroquinolones, or cefepime (odds ratio, 2.0-9.8 in CDI case patients compared with those without CDI) as intervention targets and selected several interventions (all included a component of audit and feedback). Varying degrees of success were observed in reducing antibiotic consumption over time. Total target antibiotic use significantly decreased (P < .05) when measured by days of therapy and number of courses but not by defined daily dose. Intravenous moxifloxacin and oral ciprofloxacin use showed significant reduction when measured by defined daily dose and days of therapy (P ≤ .01). Number of courses with all forms of these antibiotics was reduced (P ≤ .005). Intervention hospitals reported fewer hospital-onset CDI cases (2.8 rate point difference) compared with nonintervention hospitals; however, we were unable to show statistically significant decreases in aggregate hospital-onset CDI either between intervention and nonintervention groups or within the intervention group over time.
Although decreases in target antibiotic consumption did not translate into reductions of hospital-onset CDI in this study, many valuable lessons (including implementation strategies and antibiotic consumption measures) were learned. The findings can inform potential policy decisions regarding incorporating control of CDI and ASP as healthcare quality measures.
This multicentre surveillance study was conducted to investigate the trends in incidence and aetiology of healthcare-associated bloodstream infections (HCA-BSIs) in Taiwan. From 2000 to 2011 a total of 56 830 HCA-BSIs were recorded at three medical centres, and coagulase-negative staphylococci (CoNS) were the most common pathogens isolated (n = 9465, 16·7%), followed by E. coli (n = 7599, 13·4%). The incidence of all HCA-BSIs in each and all hospitals significantly increased over the study period owing to the increase of aerobic Gram-positive cocci and Enterobacteriaceae by 4·2% and 3·6%, respectively. Non-fermenting Gram-negative bacteria, Bacteroides spp. and Candida spp. also showed an increase but there was a significant decline in the numbers of methicillin-resistant S. aureus. In conclusion, the incidence of HCA-BSIs in Taiwan is significantly increasing, especially for Enterobacteriaceae and aerobic Gram-positive cocci.
Enzyme-Linked Immuno-Sorbent Assay (ELISA), and other methods based on the same principle, are sensitive and specific, but they suffer from several disadvantages, such as their inherent complexity and requirement for multiple reagents, incubation and washing steps and require a relatively large sample size. We have adapted a new carbon nanotube field effect transistors (CNT-FET) based platform to capture Escherichia coli antigens using only the capture anti-body showing good correlation with an established ELISA assay contrived positive and negative specimens were used to test the new CNT-FET platform and results were obtained within three minutes per each sample. The test is easy to perform, rapid, and cost efficient making it a valuable screening tool for E. coli. In this study, we looked at the applicability of using CNT field effect transistor based biosensor as a rapid diagnostic platform for Escherichia coli O157:H7. The CNT-FETs platform detected positive E. coli samples in three minutes using only 2.5 μL of sample volume. This low sample volume required by the CNT-FET platform can be especially advantageous for diagnostic tests constricted by limited amount of samples.
Background: The Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological Assessment Battery (CERAD-NAB) offers information on the clinical diagnosis of Alzheimer's disease (AD) and gives a profile of cognitive functioning. This study explores the effects of age, education and gender on participants' performance on eight subtests in the Chinese-Cantonese version of the CERAD-NAB.
Methods: The original English version of the CERAD-NAB was translated and content-validated into a Chinese-Cantonese version to suit the Hong Kong Chinese population. The battery was administered to 187 healthy volunteers aged 60 to 94 years. Participants were excluded if they had neurological, medical or psychiatric disorders (including dementia). Stepwise multiple linear regression analyses were performed to assess the relative contribution of the demographic variables to the scores on each subtest.
Results: The Cantonese version of CERAD-NAB was shown to have good content validity and excellent inter-rater reliability. Stepwise multiple regression analyses revealed that performances on seven and four out of eight subtests in the CERAD-NAB were significantly influenced by education level and age, respectively. Age and education had significant effects on participants' performance on many tests. Gender also showed a significant effect on one subtest.
Conclusions: The preliminary data will serve as an initial phase for clinical interpretation of the CERAD-NAB for Cantonese-speaking Chinese elders.
Common igniters such as black powder, benite, and boron potassium nitrate (BKNO3) are routinely employed in all calibers of gun systems. Armament Research Development Engineering Center (ARDEC) has pursued efforts to improve the ignition of gun propellants which has been demonstrated to be the root cause of many tribulations for gun systems. We have developed several extrudable nitrocellulose-BKNO3 based igniter materials that are more energetic, and exhibit smaller ignition delay times than most traditional igniters. We have demonstrated this via static firing. High speed video during static testing has demonstrated significantly more consistent, intense, and rapid flame generation in comparison to Benite leading to improved ignition effectiveness of the propellant bed.
The complexity of layered-spinel yLi2MnO3·(1 – y)Li1+xMn2–xO4 (Li:Mn = 1.2:1; 0 ≤ x ≤ 0.33; y ≥ 0.45) composites synthesized at different temperatures has been investigated by a combination of x-ray diffraction (XRD), x-ray absorption spectroscopy (XAS), and nuclear magnetic resonance (NMR). While the layered component does not change substantially between samples, an evolution of the spinel component from a high to a low lithium excess phase has been traced with temperature by comparing with data for pure Li1+xMn2–xO4. The changes that occur to the structure of the spinel component and to the average oxidation state of the manganese ions within the composite structure as lithium is electrochemically removed in a battery have been monitored using these techniques, in some cases in situ. Our 6Li NMR results constitute the first direct observation of lithium removal from Li2MnO3 and the formation of LiMnO2 upon lithium reinsertion.
Selective Chemical Vapor Deposition of Crystalline Ge-Sb-Te alloys initiating at the bottom metal contact of vias of various sizes has been accomplished. The method is based on selecting Sb and Te precursors which do not decompose on dielectric surfaces in the utilized temperature range.
Phase-change kinetics, structure evolution and feasibility to phase-change memory (PCM) of Ag2In7Sb64Te27 (AIST) and its nanocomposite comprised of 85 wt.% AIST and 15 wt.% SiO2 were presented. In-situ heating x-ray diffraction (XRD) indicated nanocomposite transforms from amorphous to HCP structure during heating and incorporation of SiO2 increases the recrystallization temperature (Tx) of samples (189°C for AIST and 223°C for nanocomposite). XRD and transmission electron microscopy (TEM) analyses both revealed the grain refinement in nanocomposite. Kissinger's analysis found the increase of activation energy (Ea) of phase transition in nanocomposite, denoting the SiO2 embedment restrains the grain growth of AIST during recrystallization. Johnson-Mehl-Avrami (JMA) theory revealed the decrease of Avrami exponent (n), indicating that the phase transition is prone to be heterogeneous since the dispersed SiO2 particles may provide additional nucleation sites.
Static I–V measurement indicated that the switching threshold voltage (Vth) of nanocomposite device (1.65 V) is higher than that of the AIST device (1.10 V). Increase of dynamic resistance in nanocomposite device leads to the reduction of writing current. I–V analysis also confirmed the retardation of recrystallization in AIST due to the incorporation of SiO2 and the rise of Ea is able to enhance the thermal stability of amorphous state in PCM devices.