bluuebunny/crossref_metadata_2025 huggingface dataset:
The origin of the elements: a century of progress
Authors: Johnson Jennifer A. , Fields Brian D. , Thompson Todd A.
Published: August 2020

This review assesses the current state of knowledge of how the elements were produced in the Big Bang, in stellar lives and deaths, and by interactions in interstellar gas. We begin with statements of fact and discuss the evidence that convinced astronomers that the Sun is fusing hydrogen, that low-mass stars produce heavy elements through neutron capture, that massive stars can explode as supernovae and that supernovae of all types produce new elements. Nucleosynthesis in the Big Bang, through cosmic ray spallation, and in exploding white dwarfs is only ranked below the above facts in certainty because the evidence, while overwhelming, is so far circumstantial. Next, we highlight the flaws in our current understanding of the predictions for lithium production in the Big Bang and/or its destruction in stars and for the production of the elements with atomic number

Z
∼
45

. While the theory that neutron star mergers produce elements through neutron-capture has powerful circumstantial evidence, we are unconvinced that they produce all of the elements past nickel. Also in dispute is the exact mechanism or mechanisms that cause the white dwarfs to explode. It is difficult to determine the origin of rare isotopes because signatures of their production are weak. We are uncertain about the production sites of some lithium and nitrogen isotopes and proton-rich heavy nuclei. Finally, Betelgeuse is probably not the next star to become a supernovae in the Milky Way, in part because Betelgeuse may collapse directly to a black hole instead. The accumulated evidence in this review shows that we understand the major production sites for the elements, but islands of uncertainty in the periodic table exist. Resolving these uncertainties requires in particular understanding explosive events with compact objects and understanding the nature of the first stars and is therefore primed for new discoveries in the next decades.

This article is part of the theme issue ‘Mendeleev and the periodic table’.
Henry Moseley, X-ray spectroscopy and the periodic table
Authors: Egdell Russell G. , Bruton Elizabeth
Published: August 2020

Just over 100 years ago, Henry Moseley carried out a systematic series of experiments which showed that the frequencies of the X-rays emitted from an elemental target under bombardment by cathode rays were characteristic of that element and could be used to identify the charge on its atomic nucleus. This led to a reorganization of the periodic table, with chemical elements now arranged on the basis of atomic number Z rather than atomic weight A, as had been the case in previous tables, including those developed by Mendeleev. Moseley also showed that there were four ‘missing elements’ before gold. With further measurements up to uranium Z = 92, the Swedish physicist Manne Siegbahn identified two more missing elements. This paper provides an introduction to Moseley and his experiments and then traces attempts to ‘discover’ missing elements by X-ray spectroscopy. There were two successes with hafnium (Z = 72) and rhenium (Z = 75), but many blind alleys and episodes of self-deception when dealing with elements 43, 61, 85 and 87. These all turned out to be radioactive, with extremely small natural abundances: all required synthesis by a nuclear reaction, with radiological characterization in the first instance. Finally, the paper moves on to consider the role of X-ray spectroscopy in exploring the periodic table beyond uranium. Although the discovery of artificial radioactive elements with Z > 92 again depended on nucleosynthesis and radiological characterization, measurement of the frequencies or energies of characteristic X-rays remains the ultimate goal in proving the existence of an element.

This article is part of the theme issue ‘Mendeleev and the periodic table’.
Relativity and the periodic table
Authors: Pyper N. C.
Published: August 2020

The periodic table provides a deep unifying principle for understanding chemical behaviour by relating the properties of different elements. For those belonging to the fifth and earlier rows, the observations concerning these properties and their interrelationships acquired a sound theoretical basis by the understanding of electronic behaviour provided by non-relativistic quantum mechanics. However, for elements of high nuclear charge, such as occur in the sixth and higher rows of the periodic table, the systematic behaviour explained by non-relativistic quantum mechanics begins to fail. These problems are resolved by realizing that relativistic quantum mechanics is required in heavy elements where electrons velocities can reach significant fractions of the velocity of light. An essentially non-mathematical description of relativistic quantum mechanics explains how relativity modifies valence electron behaviour in heavy elements. The direct relativistic effect, arising from the relativistic increase of the electron mass with velocity, contracts orbitals of low angular momentum, increasing their binding energies. The indirect relativistic effect causes valence orbitals of high angular momentum to be more effectively screened as a result of the relativistic contraction of the core orbitals. In the alkali and alkaline earths, the s orbital contractions reverse the chemical trends on descending these groups, with heavy elements becoming less reactive. For valence d and f electrons, the indirect relativistic effect enhances the reductions in their binding energies on descending the periodic table. The d electrons in the heavier coinage metals thus become more chemically active, which causes these elements to exhibit higher oxidation states. The indirect effect on d orbitals causes the chemistries of the sixth-row transition elements to differ significantly from the very similar behaviours of the fourth and fifth-row transition series. The relativistic destabilization of f orbitals causes lanthanides to be chemically similar, forming mainly ionic compounds in oxidation state three, while allowing the earlier actinides to show a richer range of chemical behaviour with several higher oxidation states. For the 7p series of elements, relativity divides the non-relativistic p shell of three degenerate orbitals into one of much lower energy with the energies of the remaining two being substantially increased. These orbitals have angular shapes and spin distributions so different from those of the non-relativistic ones that the ability of the 7p elements to form covalent bonds is greatly inhibited.

This article is part of the theme issue ‘Mendeleev and the periodic table’.
Fuels, power and chemical periodicity
Authors: Yao B. , Kuznetsov V. L. , Xiao T. , Jie X. , Gonzalez-Cortes S. , Dilworth J. R. , Al-Megren H. A. , Alshihri S. M. , Edwards P. P.
Published: August 2020

The insatiable—and ever-growing—demand of both the developed and the developing countries for power continues to be met largely by the carbonaceous fuels comprising coal, and the hydrocarbons natural gas and liquid petroleum. We review the properties of the chemical elements, overlaid with trends in the periodic table, which can help explain the historical—and present—dominance of hydrocarbons as fuels for power generation. However, the continued use of hydrocarbons as fuel/power sources to meet our economic and social needs is now recognized as a major driver of dangerous global environmental changes, including climate change, acid deposition, urban smog and the release of many toxic materials. This has resulted in an unprecedented interest in and focus on alternative, renewable or sustainable energy sources. A major area of interest to emerge is in hydrogen energy as a sustainable vector for our future energy needs. In that vision, the issue of hydrogen storage is now a key challenge in support of hydrogen-fuelled transportation using fuel cells. The chemistry of hydrogen is itself beautifully diverse through a variety of different types of chemical interactions and bonds forming compounds with most other elements in the periodic table. In terms of their hydrogen storage and production properties, we outline various relationships among hydride compounds and materials of the chemical elements to provide some qualitative and quantitative insights. These encompass thermodynamic and polarizing strength properties to provide such background information. We provide an overview of the fundamental nature of hydrides particularly in relation to the key operating parameters of hydrogen gravimetric storage density and the desorption/operating temperature at which the requisite amount of hydrogen is released for use in the fuel cell. While we await the global transition to a completely renewable and sustainable future, it is also necessary to seek CO
2
mitigation technologies applied to the use of fossil fuels. We review recent advances in the strategy of using hydrocarbon fossil fuels themselves as compounds for the high capacity storage and production of hydrogen without any CO
2
emissions. Based on these advances, the world may end up with a hydrogen economy completely different from the one it had expected to develop; remarkably, with ‘Green hydrogen' being derived directly from the hydrogen-stripping of fossil fuels.

This article is part of the theme issue ‘Mendeleev and the periodic table'.
The transuranic elements and the island of stability
Authors: Chapman Kit
Published: August 2020

Since the 1930s the synthesis of nuclides too unstable to exist naturally on Earth has stretched the periodic table to 118 elements. While the lighter transuranic elements have found uses, the isotopes of those past lawrencium, the superheavy elements, are too unstable to exist outside the laboratory. In the 1970s, leading element discoverers Glenn Seaborg at the University of California, Berkeley, USA, and Georgy Flerov, at the Joint Institute for Nuclear Research in Dubna, USSR, took interest in a supposed ‘island of stability’, leading from the nuclear shell model of Maria Goeppert Mayer and Hans Jensen, and predicted elements with so-called magic numbers of protons and neutrons would be far more stable. This review shall look at the historical developments that led to the field of element discovery, the attempts to discover superheavy elements in nature based on the island of stability, and the subsequent successful synthesis of elements and the implications of their half-lives and properties.

This article is part of the theme issue ‘Mendeleev and the periodic table’.
Abusers indoors and coronavirus outside: an examination of public discourse about COVID-19 and family violence on Twitter using machine learning
Authors: Xue Jia , Chen Junxiang , Chen Chen , Hu Ran , Zhu Tingshao
Published: August 2020

Purpose

This brief report aims to provide the first large-scale analysis of public discourse regarding family violence and the COVID-19 pandemic on Twitter. Method: We analyzed 301,606 Tweets related to family violence and COVID-19 from April 12 to July 16, 2020, for this study. We used the machine learning approach, Latent Dirichlet Allocation, and identified salient themes, topics, and representative Twitter examples.

Results

We extracted nine themes on family violence and COVID-19 pandemic, including (1) the Impact of COVID-19 on family violence (e.g., rising rates, hotline calls increased, murder & homicide); (2) the types (e.g., child abuse, domestic violence, sexual violence) and (3) forms of family violence (e.g., physical aggression, coercive control); (4) risk factors of family violence (e.g., alcohol abuse, financial constraints, gun, quarantine); (5) victims of family violence (e.g., LGBTQ, women, and women of color, children); (6) social services of family violence (e.g., hotlines, social workers, confidential services, shelters, funding); (7) law enforcement response (e.g., 911 calls, police arrest, protective orders, abuse reports); (8) Social movement/awareness (e.g., support victims, raise awareness); and (9) domestic violence-related news (e.g., Tara Reade, Melissa Derosa).

Conclusions

The COVID-19 has an impact on family violence. This report overcomes the limitation of existing scholarship that lacks data for consequences of COVID-19 on family violence. We contribute to the understanding of family violence during the pandemic by providing surveillance in Tweets, which is essential to identify potentially effective policy programs in offering targeted support for victims and survivors and preparing for the next wave.
Detection of cognitive decline using a single-channel EEG with an interactive assessment tool
Authors: Molcho Lior , Maimon Neta B. , Pressburger Narkiss , Regev-Plotnik Noa , Rabinowicz Sarit , Intrator Nathan , Sasson Ady
Published: August 2020

Background

Cognitive decline remains highly underdiagnosed despite efforts to find novel biomarkers for detection. EEG biomarkers based on machine learning may offer a noninvasive low-coast approach for identifying cognitive decline. However, most studies use multi-electrode systems which are less accessible. This study aims to evaluate the ability to extract cognitive decline biomarkers using a wearable single-channel EEG system with an interactive assessment tool.

Methods

This pilot study included data collection from 82 participants who performed a cognitive assessment while being recorded with a single-channel EEG system. Seniors in different clinical stages of cognitive decline (healthy to mild dementia) and young healthy participants were included. Seniors’ MMSE scores were used to allocate groups with cutoff scores of 24 and 27. Data analysis included correlation analysis as well as linear mixed model analysis with several EEG variables including frequency bands and three novel cognitive biomarkers previously extracted from a different dataset.

Results

MMSE scores correlated significantly with reaction times, as well as two EEG biomarkers: A0 and ST4. Both biomarkers showed significant separation between study groups: ST4 separated between the healthy senior group and the low-MMSE group. A0 differentiated between the healthy senior group and the other three groups, showing different cognitive patterns between different stages of cognitive decline as well as different patterns between young and senior healthy participants. In the healthy young group, activity of Theta, Delta, A0 and VC9 biomarkers significantly separated between high and low levels of cognitive load, consistent with previous reports. VC9 and Theta showed a finer separation between low cognitive load levels and resting state.

Conclusions

This study successfully demonstrated the ability to assess cognitive states with an easy-to-use portable single-channel EEG device with an interactive cognitive assessment. The short set-up time and novel biomarkers enable objective and easy assessment of cognitive decline. Future studies should explore potential usefulness of this tool in characterizing changes in EEG patterns of cognitive decline over time, for detection of cognitive decline on a large scale in every clinic to potentially allow early intervention.
The Effect of Neutropenia and Filgrastim (G-CSF) in Cancer Patients With COVID-19 Infection
Authors: Morjaria Sejal , Zhang Allen W , Kaltsas Anna , Parameswaran Rekha , Patel Dhruvkumar , Zhou Wei , Predmore Jacqueline , Perez-Johnston Rocio , Jee Justin , Perales Miguel-Angel , Daniyan Anthony F. , Taur Ying , Mailankody Sham
Published: August 2020

Background

Neutropenia is commonly encountered in cancer patients, and recombinant human granulocyte colony-stimulating factor (G-CSF, filgrastim) is widely given to oncology patients to counteract neutropenia and prevent infection. G-CSF is both a growth factor and cytokine that initiates proliferation and differentiation of mature granulocytes. However, the clinical impact of neutropenia and G-CSF use in cancer patients, who are also afflicted with coronavirus disease 2019 (COVID-19), remains unknown.

Methods

An observational cohort of 304 hospitalized patients with COVID-19 at Memorial Sloan Kettering Cancer Center was assembled to investigate links between concurrent neutropenia (N=55) and G-CSF administration (N=16) on COVID-19-associated respiratory failure and death. These factors were assessed as time-dependent predictors using an extended Cox model, controlling for age and underlying cancer diagnosis. To determine whether the degree of granulocyte response to G-CSF affected outcomes, a similar model was constructed with patients that received G-CSF, categorized into “high”- and “low”- response, based on the level of absolute neutrophil count (ANC) rise 24 hours after growth factor administration.

Results

Neutropenia (ANC < 1 K/mcL) during COVID-19 course was not independently associated with severe respiratory failure or death (HR: 0.71, 95% Cl: 0.34-1.50, P value: 0.367) in hospitalized COVID-19 patients. When controlling for neutropenia, G-CSF administration was associated with increased need for high oxygen supplementation and death (HR: 2.97, 95% CI: 1.06-8.28, P value: 0.038). This effect was predominantly seen in patients that exhibited a “high” response to G-CSF based on their ANC increase post-G-CSF administration (HR: 5.18, 95% CI: 1.61-16.64, P value: 0.006).

Conclusion

Possible risks versus benefits of G-CSF administration should be weighed in neutropenic cancer patients with COVID-19 infection, as G-CSF may lead to worsening clinical and respiratory status in this setting.
Life-course burden of health deficits associates with later-life heart size and function in the 1946 British birth cohort
Authors: Topriceanu Constantin-Cristian , Moon James C , Hardy Rebecca , Chaturvedi Nish , Hughes Alun D , Captur Gabriella
Published: August 2020

Aim

To study the association between the life-course accumulation of health deficits and later-life heart size and function using data from the 1946 National Survey of Heath and Development (NSHD) British birth cohort, the world’s longest running birth cohort with continuous follow-up.

Methods and Results

A multidimensional health deficit index (DI) looking at 45-health deficits was serially calculated at 4 time periods of the life-course in NSHD participants (0-16, 19-44, 45-54 and 60 to 64 years), and from these the mean and total DI for the life-course was derived (DImean, DIsum). The step change in deficit accumulation from one time period to another was also calculated. Echocardiographic data at 60-64 years provided: ejection fraction (EF), left ventricular mass indexed to body surface area (LVmassi, BSA), myocardial contraction fraction indexed to BSA (MCFi) and E/e’. Generalized linear models assessed the association between DIs and echocardiographic parameters after adjustment for sex, socio-economic position and body mass index.

1,375 NSHD participants were included (46.47% male). For each single new deficit accumulated at any one of the 4 time periods of the life-course, LVmassi increased by 0.91-1.44% (p<0.013), while MCFi decreased by 0.6-1.02% (p<0.05 except at 45-54 years). One unit increase in DI at age 45-54 and 60-64 decreased LV EF by 11-12% (p<0.013). A single deficit step change occurring between 60-64 years and one of the earlier time periods, translated into significantly higher odds (2.1—78.5, p<0.020) of elevated LV filling pressure defined as E/e’>13.

Conclusion

The accumulation of health deficits at any time period of the life-course associates with a maladaptive cardiac phenotype in older age, dominated by myocardial hypertrophy and poorer function. The burden of health deficits appears to strain the myocardium potentially leading to future cardiac dysfunction.
Sixty-day mortality among 520 Italian hospitalized COVID-19 patients according to the adopted ventilatory strategy in the context of an integrated multidisciplinary clinical organization: a population-based cohort study
Authors: Potalivo Antonella , Montomoli Jonathan , Facondini Francesca , Sanson Gianfranco , Agli Luigi Arcangelo Lazzari , Perin Tiziana , Cristini Francesco , Cavagna Enrico , De Giovanni Raffaella , Biagetti Carlo , Panzini Ilaria , Ravaioli Cinzia , Bitondo Maddalena , Guerra Daniela , Giuliani Giovanni , Mosconi Elena , Guarino Sonia , Marchionni Elisa , Gangitano Gianfilippo , Valentini Ilaria , Giampaolo Luca , Muratore Francesco , Nardi Giuseppe
Published: August 2020

Background

Among COVID-19 patients, the decision of which ventilation strategy to adopt is crucial and not guided by existing outcome evidence. We described the clinical characteristics and outcomes of hospitalized COVID-19 patients according to the adopted respiratory strategy.

Methods

Population-based cohort study including all COVID-19 patients (26/02/2020-18/04/2020) within Rimini Italian province. Hospitalized patients were classified according to the maximum level of respiratory support: oxygen supplementation (group Oxygen), NIV (group NIV-only), IMV (group IMV-only), and IMV after a NIV trial (group IMV-after-NIV). Sixty-day mortality risk was estimated with a Cox proportional hazard analysis adjusted by age, sex, and administration of steroids, canakinumab, and tocilizumab.

Findings

We identified 1,424 symptomatic patients: 520 (36.5%) were hospitalized, the remaining 904 (63.5%) were treated at home with no 60-days death. According to the respiratory support, 408 (78.5%) were assigned to Oxygen, 46 (8.8%) to NIV-only, 25 (4.8%) to IMV-after-NIV, and 41 (7.9%) to IMV-only groups. There was no significant difference in the P/F at IMV inception among IMV-after-NIV and IMV-only groups (p=0.9). Overall 60-day mortality was 24.2% (Oxygen: 23.0%; NIV-only: 19.6%; IMV-after-NIV: 32.0%; IMV-only: 36.6%; p = 0.165). Compared with Oxygen group, the 60-day mortality risk significantly increased for IMV-after-NIV (HR 2.776; p=0.024) and IMV-only group (HR 2.966; p=0.001).

Conclusions

This study provides a population-based figure of the impact of the COVID-19 epidemic. A similar 60-days mortality risk was found for patients undergoing immediate IMV and those intubated after a NIV trial. Many patients had a favorable outcome after prolonged IMV.
Forecasting American COVID-19 Cases and Deaths through Machine Learning
Authors: Somalwar Anaiy
Published: August 2020

COVID-19 has become a great national security problem for the United States and many other countries, where public policy and healthcare decisions are based on the several models for the prediction of the future deaths and cases of COVID-19. While the most commonly used models for COVID-19 include epidemiological models and Gaussian curve-fitting models, recent literature has indicated that these models could be improved by incorporating machine learning. However, within this research on potential machine learning models for COVID-19 forecasting, there has been a large emphasis on providing an array of different types of machine learning models rather than optimizing a single one. In this research, we suggest and optimize a linear machine learning model with a gradient-based optimizer for the prediction of future COVID-19 cases and deaths in the United States. We also suggest that a hybrid of a machine learning model for shorter range predictions and a Gaussian curve-fitting model or an epidemiological model for longer range predictions could greatly increase the accuracy of COVID-19 forecasting.
Functional activation changes at ultra-high field related to upper and lower limb impairments in multiple sclerosis
Authors: Strik Myrte , Shanahan Camille J. , van der Walt Anneke , Boonstra Frederique M. C. , Glarin Rebecca , Galea Mary P. , Kilpatrick Trevor J. , Geurts Jeroen J.G. , Cleary Jon O. , Schoonheim Menno M. , Kolbe Scott C.
Published: August 2020

Upper and lower limb impairments are common in people with multiple sclerosis (pwMS), yet difficult to clinically identify in early stages of disease progression. Tasks involving complex motor control can potentially reveal more subtle deficits in early stages, and can be performed during functional MRI acquisition, to investigate underlying neural mechanisms, providing markers for early motor progression. We investigated brain activation during visually-guided force-matching of hand or foot in 28 minimally disabled pwMS and 17 healthy controls (HC) using ultra-high field 7-Tesla fMRI, allowing us to visualise sensorimotor network activity in high detail. Task activations and performance (tracking lag and error) were compared between groups, and correlations were performed. PwMS showed delayed (+124 s, p=0.002) and more erroneous (+0.15 N, p=0.001) lower limb tracking, together with higher primary motor and premotor cortex activation, and lower cerebellar activation compared to HC. No differences were seen in upper limb performance or activation. Functional activation levels of cerebellar, visual and motor areas correlated with task performance. These results demonstrate that ultra-high field fMRI during complex hand and foot tracking can identify subtle impairments in movement and brain activity, and differentiates upper and lower limb impairments in minimally disabled pwMS.
England’s Lockdown vs. Sweden’s Herd Immunity: A Comparison of the Daily New COVID-19 Cases and Related Deaths Using Comparative Interrupted Time Series Analysis
Authors: Mustafa Ali Moaath K. , Samhouri Yazan , Sabha Marwa , Alnimer Lynna
Published: August 2020

Background

There is a lack of empirical evidence that lockdowns decrease daily cases of COVID-19 and related mortality compared to herd immunity. England implemented a delayed lockdown on March 23, 2020, but Sweden did not. We aim to examine the effect of lockdown on daily COVID-19 cases and related deaths during the first 100 days post-lockdown.

Methods

We compared daily cases of COVID-19 infection and related mortality in England and Sweden before and after lockdown intervention using a comparative-interrupted time series analysis. The period included was from COVID-19 pandemic onset till June 30, 2020.

Results

The adjusted-rate of daily COVID-19 infections was eight cases/10,000,000 person higher in England than Sweden before lockdown order (95% CI: 2-14, P=0.01). On the day of intervention (lagged lockdown), England had 693 more COVID-19 cases/10,000,000 person compared to Sweden (95% CI: 467-920, P<0.001). Compared to the pre-intervention period, the adjusted daily confirmed cases rate decreased by 19 cases/ 10,000,000 person compared to Sweden (95% CI: 13-26, P<0.001). There was a rate excess of 1.5 daily deaths/ 10,000,000 person in England compared to Sweden pre-intervention (95% CI: 1-2, P<0.001). The increased mortality rate resulted in 50 excess deaths/ 10,000,000 person related to COVID-19 in England compared to Sweden on the day of lockdown (95% CI: 30-71, P<0.001). Post-intervention, the rate of daily deaths in England decreased by two deaths/ 10,000,000 person compared to Sweden (95% CI: 1-3, P<0.001). During phases one and two of lockdown lifting in England, there was no rebound increase in daily cases or deaths compared to Sweden.

Conclusion

The lockdown order implemented in England on March 23, 2020, effectively decreased the daily new cases rate and related mortality compared to Sweden. There was no short-term increase in COVID-19 cases and related-deaths after the phases one and two of the lifting of restrictions in England compared to Sweden. This study provides empirical, comparative evidence that lockdowns slow the spread of COVID-19 in communities compared to herd immunity.
Dynamical balance between the transmission, intervention of COVID-19 and economic development
Authors: Zhang Zhaowang , Lin Hualiang , Zhu Guanghu
Published: August 2020

The current explosive outbreak of coronavirus (COVID-19) is posing serious threats to public health and economy around the world. To clarify the coupling mechanism between this disease and economy, a new dynamical system is established. It is theoretically proved that the basic reproduction number is a nonlinear combination of parameters regarding disease transmission, intervention and economy effect, which totally determines the stability of the disease-free and endemic equilibria. Further results indicate the existence of interaction and mutual restraint among the transmission, intervention and economy, in which strong coupling of COVID-19 and economy would trigger disease outbreak and form poverty trap, while adaptive isolation of at-risk population could effectively reduce morbidity at the cost of least economic loss. Our findings can offer new insights to improve the intervention strategies against COVID-19.
Age-dependent and Independent Symptoms and Comorbidities Predictive of COVID-19 Hospitalization
Authors: Huang Yingxiang , Radenkovic Dina , Perez Kevin , Nadeau Kari , Verdin Eric , Furman David
Published: August 2020

The coronavirus disease 2019 (COVID-19) pandemic, caused by Severe Acute Respiratory Syndrome (SARS)-CoV-2, continues to burden medical institutions around the world by increasing total hospitalization and Intensive Care Unit (ICU) admissions1–9 A better understanding of symptoms, comorbidities and medication used for preexisting conditions in patients with COVID-19 could help healthcare workers identify patients at increased risk of developing more severe disease10,11. Here, we have used self-reported data (symptoms, medications and comorbidities) from more than 3 million users from the COVID-19 Symptom Tracker app12 to identify previously reported and novel features predictive of patients being admitted in a hospital setting. Despite previously reported association between age and more severe disease phenotypes13–18, we found that patient’s age, sex and ethnic group were minimally predictive when compared to patient’s symptoms and comorbidities. The most important variables selected by our predictive algorithm were fever, the use of immunosuppressant medication, mobility aid, shortness of breath and fatigue. It is anticipated that early administration of preventative measures in COVID-19 positive patients (COVID+) who exhibit a high risk of hospitalization signature may prevent severe disease progression.
Estimating the epidemic growth dynamics within the first week
Authors: Fioriti Enzo , Chinnici Marta , Arbore Andrea , Sigismondi Nicola , Roselli Ivan
Published: August 2020

Information about the early growth of infectious outbreaks are indispensable to estimate the epidemic spreading. A large number of mathematical tools have been developed to this end, facing as much large number of different dynamic evolutions, ranging from sub-linear to super-exponential growth. Of course, the crucial point is that we do not have enough data during the initial outbreak phase to make reliable inferences. Here we propose a methodology to estimate the epidemic growth dynamics from the infected cumulative data of just a week, provided a surveillance system is available over the whole territory. The methodology, based on the Newcomb-Benford Law, is applied to Italian covid 19 case-study. Results show that it is possible to discriminate the epidemic dynamics using the first seven data points collected over fifty Italian cities. Moreover, the form of the most probable approximating function of the growth, within a six weeks epidemic scenario, is identified.
Pre-COVID-19 humoral immunity to common coronaviruses does not confer cross-protection against SARS-CoV-2
Authors: Miyara Makoto , Sterlin Delphine , Anna François , Marot Stéphane , Mathian Alexis , Atif Mo , Quentric Paul , Mohr Audrey , Claër Laetitia , Parizot Christophe , Dorgham Karim , Yssel Hans , Chazal Thibaud , Fadlallah Jehane , Haroche Julien , Benameur Neila , Boutolleau David , Burrel Sonia , Mudumba Sasi , Hockett Rick , Gunn Cary , Charneau Pierre , Calvez Vincent , Marcellin Anne-Geneviève , Amoura Zahir , Gorochov Guy
Published: August 2020

It is currently unknown whether acquired immunity to common alpha- and beta-coronaviruses provides cross-protection against SARS-CoV-2. In this study, we found that certain patient sera and intravenous immunoglobulins (IVIG) collected prior to the COVID-19 outbreak were cross-reactive to SARS-CoV-2 full-length Spike, S2 domain, and Nucleocapsid. However, their presence did not translate into neutralizing activity against SARS-CoV-2in vitro. Importantly, we detected serum IgG reactivity to common coronaviruses in the early sera of patients with severe COVID-19 before the appearance of anti-SARS-CoV-2 antibodies. Collectively, the results of our study indicate that pre-existing immunity to common coronaviruses does not confer cross-protection against SARS-CoV-2in vivo.
Socioeconomic inequalities in prevalence and development of multimorbidity across adulthood: findings from the MRC 1946 National Survey of Health & Development
Authors: Khanolkar Amal R. , Chaturvedi Nishi , Kuan Valerie , Davis Daniel , Hughes Alun , Richards Marcus , Bann David , Patalay Praveetha
Published: August 2020

Objective

To estimate multimorbidity trajectories and quantify socioeconomic inequalities based on both childhood and adulthood socioeconomic position in the risks and rates of adult multimorbidity accumulation.

Design

Prospective longitudinal national birth cohort study.

Methods

Participants from the 1946 National Survey of Health and Development (NSHD) who attended the age 36 assessment in 1982 and any one of the follow-up assessments at ages 43, 53, 63 & 69 (N=3,723, 51% males). Information on 18 health conditions was based on a combination of self-report, biomarkers, health records and prescribed medications. We estimated multimorbidity trajectories and delineated socioeconomic inequalities (based on childhood and adulthood social class and highest education) in multimorbidity at each age and in longitudinal trajectories.

Results

Multimorbidity increased with age from 0.7 conditions on average at 36 years to 3.7 at 69 years. Multimorbidity accumulation was non-linear, accelerating with age at the rate of 0.08 conditions/year (95% CI 0.07-0.09) at 36-43 years to 0.19 conditions/year (95% CI 0.18-0.20) at 63-69 years. At all ages, the most socio-economically disadvantaged had 1.2 to 1.4 times greater number of conditions on average compared to the most advantaged. The most socioeconomically disadvantaged by each socioeconomic indicator experienced an additional 0.39 conditions (childhood social class), 0.83 (adult social class) and 1.08 conditions (adult education) at age 69 years, independent of all other socioeconomic indicators. Adverse adulthood socioeconomic status was associated with more rapid accumulation of multimorbidity, resulting in 0.49 excess conditions in partly/unskilled compared to professional/intermediate individuals between 63-69 years. Disadvantaged childhood social class, independently of adult socio-economic position, was associated with accelerated multimorbidity trajectories from age 53 onwards.

Conclusions

Socioeconomically disadvantaged individuals have both earlier onset and more rapid accumulation of multimorbidity resulting in widening inequalities into old age, with independent contributions from both childhood and adulthood socio-economic position.
Stethoscope and Non-Infrared Thermometer Disinfection among Physicians: A Cross-Sectional Study with Implications for the Control of COVID-19
Authors: Sahiledengle Biniyam , Tekalegn Yohannes , Bekele Kebebe , Tesemma Abdi , Quisido Bruce John Edward
Published: August 2020

Background

Stethoscopes and non-infrared thermometers are the customary medical equipment used by the physicians on a daily basis, among various patients. With the rise of potential infections in the healthcare facilities and the transmission nature of the current volantly evolving COVID-19, consistent and correct disinfections of these devices after each use should not be pardoned. This study, therefore, describes the level of stethoscope and non-infrared thermometer disinfection practices among physicians and determines its associated factors during the COVID-19 pandemic.

Methods

A nationwide cross-sectional online survey was circulated using an anonymous and self-reporting questionnaire via Google form with a consent form appended to it.

Results

Four hundred twenty-two physicians participated (62.80% medical doctors, 33.65% seniors, and 3.55% residents). The proportion of stethoscope and non-Infrared thermometer disinfections after every use was 13.9% (95%CI: 10.9-17.6) and 20.4% (95%CI: 16.7-24.5), respectively. In adjusted analyses, taking COVID-19 training (Adjusted Odds Ratio [AOR]: 2.52; 95% [Confidence Interval (CI)]: 1.29-4.92) and the availability of stethoscope disinfection materials at the workplace (AOR: 3.03; 95% CI: 1.29-7.10) were significantly increased the odds of stethoscope disinfection after every use. The odds of stethoscope disinfection after every use was significantly decreased for those who reported the use of shared stethoscope (AOR: 0.34; 95% CI: 0.12-0.92). Among the physicians, disinfection after every use was significantly higher in resident physicians compared to those of general practitioners for both stethoscope (AOR: 4.61; 95%CI: 1.29-16.52) and non-Infrared thermometers (AOR: 7.10; 95%CI: 2.30-21.95).

Conclusion

Only a wee share of the respondents reported that they have disinfected their stethoscopes and non-infrared thermometers after every use – possibly jeopardizing both patients and clinicians safety, particularly during the COVID-19 pandemic – and these results must be sternly dealt with. Provisions of training and securing constant and available stethoscope disinfection supplies can significantly increase disinfection practices among the physicians after every use. These simple interventions could be replicated by other healthcare facilities.
Superspreading as a Regular Factor of the COVID-19 Pandemic: II. Quarantine Measures and the Second Wave
Authors: Dimaschko Juri
Published: August 2020

Within the framework of a two-component model of the COVID-19 epidemic, taking into account the special role of superspreaders, we consider the impact of the recovery factor and quarantine measures on the course of the epidemic, as well as the possibility of a second wave of morbidity. It is assumed that there is no long-term immunity in asymptomatic superspreaders who have undergone the infection, and the emergence of long-term immunity in those who have undergone severe illness. It is shown that, under these assumptions, the relaxation of quarantine measures leads to the resumption of virus circulation among asymptomatic superspreaders. Depending on the characteristics of the quarantine, its removal may or may not lead to a renewed wave of daily morbidity. A criterion for the occurrence of repeated wave of morbidity is proposed based on the analysis of the final phase of the first wave. Based on this criterion, the repeated wave of the epidemic is predicted in New Zealand. A natural explanation is given for the decrease in lethality among the infected against the background of an absolute increase in their number.
The basic reproduction number can be accurately estimated within 14 days after societal lockdown: The early stage of the COVID-19 epidemic in Denmark
Authors: Valentin Jan Brink , Møller Henrik , Johnsen Søren Paaske
Published: August 2020

Objective

Early identification of the basic reproduction number (BRN) is imperative to political decision making during an epidemic. In this study, we estimated the BRN 7, 14, 21 and 28 days after societal lockdown of Denmark during the early stage of the COVID-19 epidemic.

Method

We implemented the SEIR dynamical system for disease spread without vital dynamics. The BRN was modulated using a sigmoid function. Model parameters were estimated on number of admitted patients, number of patients in intensive care and cumulative number of deaths using the simulated annealing Monte Carlo algorithm. Results are presented with 95% prediction intervals (PI).

Results

We were unable to determine any reliable estimate of the BRN at 7 days following lockdown. The BRN had stabilised at day 14 throughout day 28, with the estimate ranging from 0.95 (95% PI: 0.92-0.98) at day 7 to 0.92 (95% PI: 0.92-0.93) at day 28. We estimated the BRN prior to lockdown to be 3.32 (95% PI: 3.31-3.33). The effect of the lockdown was occurring over a period of a few days centred at March 18th (95% PI: 17th-18th) 2020.

Conclusion

We believe our model provides a valuable tool for decision makers to reliably estimate the effect of a politically determined lockdown during an epidemic.
Impact of the COVID-19 pandemic on ongoing health research: an ad hoc survey among investigators in Germany
Authors: Bratan Tanja , Aichinger Heike , Brkic Nicole , Rueter Jana , Apfelbacher Christian , Loss Julika
Published: August 2020

Objectives

To gain insights into the impact of the COVID-19 pandemic on ongoing health research projects, using projects from a selected funding programme in Germany as an example.

Design

Online survey

Setting

Lockdowns and social distancing policies impact upon clinical and public health research in various forms, especially if unrelated to COVID-19. Research institutions have reduced onsite activities, data is often collected remotely, and during the height of the crisis, clinical researchers were partially forced to abandon their projects in favour of front-line care and crisis response.

Participants

120 investigators of health research projects across Germany, performed between 15 and 25 May 2020.

Results

The response rate (78%) showed that the survey generated significant interest among investigators. 85 responses were included for analysis, and the majority of investigators (93%) reported that their projects were affected by the pandemic, with many (80%) stating that data collection was not possible as planned, and they could not carry out interventions as planned (67%). Other impacts were caused by staff being unavailable, for example through child or elder care commitments or because of COVID-19 quarantine or illness. Investigators also reported that publications were delayed or not feasible at all (56%), and some experienced problems with PhD or Masters theses 18%). The majority of investigators had mitigation strategies in place such as adjustment of data collection methods using digital tools (46%) or of project implementation in general (46%), others made changes in research design or research questions (27%).

Conclusions

The COVID-19 pandemic has severely impacted upon health research projects. The main challenge is now to mitigate negative effects and to improve long-term resilience in health research. The pandemic has also acted as a driver of innovation and change, for example by accelerating the use of digital methods.

Strengths and limitations of this study

To our knowledge, this is the first study investigating the impact of the COVID-19 pandemic on non COVID-19 health research projects, mitigation strategies employed by investigators and needs for support.

The sample is representative of the projects from the “Healthy - for a lifetime” funding programme in Germany, which includes different types of health research projects and involves different population groups.

We were not able to clearly distinguish the effects on different types of projects (clinical studies, observational studies, secondary data analyses etc.), because a small number of investigators led more than one project and were not asked to report on each project individually.

The survey presents a snapshot of the situation in May 2020. To assess effects more widely as well as long-term impacts on projects, the survey would need to be repeated.
Modelling Suggests Limited Change in the Reproduction Number from Reopening Norwegian Kindergartens and Schools During the COVID-19 Pandemic
Authors: Rypdal Martin , Rypdal Veronika , Jakobsen Per , Ytterstad Elinor , Løvsletten Ola , Klingenberg Claus , Rypdal Kristoffer
Published: August 2020

Background

To suppress the COVID-19 outbreak, the Norwegian government closed all schools on March 13, 2020. The kindergartens reopened on April 20, and the schools on April 27 and May 11 of 2020. The effect of these measures is largely unknown since the role of children in the spread of the SARS-CoV-2 virus is still unclear. There are only a few studies of school closures as a separate intervention to other social distancing measures, and little research exists on the effect of school opening during a pandemic.

Objective

This study aimed to model the effect of opening kindergartens and the schools in Norway in terms of a change in the reproduction number (R). A secondary objective was to assess if we can use the estimated R after school openings to infer the rates of transmission between children in schools.

Methods

We used an individual-based model (IBM) to assess the reopening of kindergartens and schools in two Norwegian cities, Oslo, the Norwegian capital, with a population of approximately 680 000, and Tromsø, which is the largest city in Northern Norway, with a population of approximately 75 000. The model uses demographic information and detailed data about the schools in both cities. We carried out an ensemble study to obtain robust results in spite of the considerable uncertainty that remains about the transmission of SARS-CoV-2.

Results

We found that reopening of Norwegian kindergartens and schools are associated with a change in R of 0.10 (95%CI 0.04-0.16) and 0.14 (95%CI 0.01-0.25) in the two cities under investigation if the in-school transmission rates for the SARS-CoV-2 virus are equal to what Ferguson et al. have previously estimated for influenza pandemics [1].

Conclusion

We found only a limited effect of reopening schools on the reproduction number, and we expect the same to hold true in other countries where nonpharmaceutical interventions have suppressed the pandemic. Consequently, current R-estimates are insufficiently accurate for determining the transmission rates in schools. For countries that have not opened schools yet, planned interventions, such as the opening of selected schools, can be useful to infer general knowledge about children-to-children transmission of SARS-CoV-2.
Development and validation of nomogram to predict long-term prognosis of critically ill patients with acute myocardial infarction
Authors: Tang Yiyang , Zha Lihuang , Zeng Xiaofang , Feng Yilu , Lin Wenchao , Liu Zhenghui , Yu Zaixin
Published: August 2020

Background

Acute myocardial infarction (AMI) is a common critical illness in the cardiovascular field, with poor prognosis. This study aimed to construct a nomogram to predict long-term survival of critically ill patients with AMI, which helps to assess severity, guide treatment, and improve prognosis.

Methods and results

The clinical data of patients with AMI was extracted from the database MIMIC-III v1.4. The Cox proportional hazards models were performed to identify the independently prognostic factors, and a nomogram for predicting long-term survival of AMI patients was developed based on the multifactor analysis, of which discriminative ability and accuracy was evaluated by concordance index (C-index) and calibration curve.

Results

A total of 1202 patients were included in the analysis, of which 841 were divided into the training set and 361 were the validation. Multivariate analysis shown that age, blood urea nitrogen, respiratory rate, SAPSII score, cardiogenic shock, cardiac arrhythmias, and respiratory failure served as the independently predictive factors, which were incorporated into the nomogram. Moreover, the nomogram shown favorable performance for predicting 4-year survival of AMI patients with the C-index of 0.788 [95% confidence interval (CI): 0.763 to 0.813] and 0.783 (95% CI: 0.748 to 0.818) in the training and validation set, respectively.

Conclusion

The nomogram we constructed here can accurately predict the long-term survival of patients with AMI.