Analysis of the Factors Associated with Negative Conversion of Severe Acute Respiratory Syndrome Coronavirus 2 RNA of Coronavirus Disease 2019

AIM: To understand the factors associated with negative conversion of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA, targeted surveillance and control measures can be taken to provide scientific basis for the treatment of the disease and to improve the prognosis of the disease. METHODS: Using the method of retrospective cohort study, we collected the data of Coronavirus Disease 2019 (COVID-19) patients in Tongji Hospital of Wuhan, China from 10 January to 25 March, 2020. Among the data of 282 cases, 271 patients, according to whether the negative conversion happened, were divided into negative conversion group and control group. We made the quantitative variables into classification; Chi-square test single-factor and Cox regression were used in univariate analysis and extracted 30 meaningful variables, then through the collinearity diagnosis, excluded the existence of collinear variables. Finally, 22 variables were included in Cox regression analysis. RESULTS: The gender distribution was statistically significant between two groups (p < 0.05). While in the negative conversion group, the patients of non-severe group occupied a large proportion (p < 0.001). The median time for the negative conversion group was 17 days, and at the end of the observation period, the virus duration in control group was 24 days (p < 0.05). A total of 55 variables were included in univariate analysis, among which 30 variables were statistically different between the two groups. After screening variables through collinearity diagnosis, 22 variables were included in the Cox regression analysis. Last, lactate dehydrogenase (LDH), age, fibrinogen (FIB), and disease severity were associated with negative conversion of SARS-CoV-2 RNA. CONCLUSION: Our results suggest that in the treatment of COVID-19, focus on the age of more than 65 years old, severe, high level of LDH, FIB patients, and take some targeted treatment, such as controlling of inflammation, reducing organ damage, so as to provide good conditions for virus clearance in the body

Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

Background: In an era of shifting global agendas and expanded emphasis on non-communicable diseases and injuries along with communicable diseases, sound evidence on trends by cause at the national level is essential. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a systematic scientific assessment of published, publicly available, and contributed data on incidence, prevalence, and mortality for a mutually exclusive and collectively exhaustive list of diseases and injuries. Methods: GBD estimates incidence, prevalence, mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) due to 369 diseases and injuries, for two sexes, and for 204 countries and territories. Input data were extracted from censuses, household surveys, civil registration and vital statistics, disease registries, health service use, air pollution monitors, satellite imaging, disease notifications, and other sources. Cause-specific death rates and cause fractions were calculated using the Cause of Death Ensemble model and spatiotemporal Gaussian process regression. Cause-specific deaths were adjusted to match the total all-cause deaths calculated as part of the GBD population, fertility, and mortality estimates. Deaths were multiplied by standard life expectancy at each age to calculate YLLs. A Bayesian meta-regression modelling tool, DisMod-MR 2.1, was used to ensure consistency between incidence, prevalence, remission, excess mortality, and cause-specific mortality for most causes. Prevalence estimates were multiplied by disability weights for mutually exclusive sequelae of diseases and injuries to calculate YLDs. We considered results in the context of the Socio-demographic Index (SDI), a composite indicator of income per capita, years of schooling, and fertility rate in females younger than 25 years. Uncertainty intervals (UIs) were generated for every metric using the 25th and 975th ordered 1000 draw values of the posterior distribution. Findings: Global health has steadily improved over the past 30 years as measured by age-standardised DALY rates. After taking into account population growth and ageing, the absolute number of DALYs has remained stable. Since 2010, the pace of decline in global age-standardised DALY rates has accelerated in age groups younger than 50 years compared with the 1990–2010 time period, with the greatest annualised rate of decline occurring in the 0–9-year age group. Six infectious diseases were among the top ten causes of DALYs in children younger than 10 years in 2019: lower respiratory infections (ranked second), diarrhoeal diseases (third), malaria (fifth), meningitis (sixth), whooping cough (ninth), and sexually transmitted infections (which, in this age group, is fully accounted for by congenital syphilis; ranked tenth). In adolescents aged 10–24 years, three injury causes were among the top causes of DALYs: road injuries (ranked first), self-harm (third), and interpersonal violence (fifth). Five of the causes that were in the top ten for ages 10–24 years were also in the top ten in the 25–49-year age group: road injuries (ranked first), HIV/AIDS (second), low back pain (fourth), headache disorders (fifth), and depressive disorders (sixth). In 2019, ischaemic heart disease and stroke were the top-ranked causes of DALYs in both the 50–74-year and 75-years-and-older age groups. Since 1990, there has been a marked shift towards a greater proportion of burden due to YLDs from non-communicable diseases and injuries. In 2019, there were 11 countries where non-communicable disease and injury YLDs constituted more than half of all disease burden. Decreases in age-standardised DALY rates have accelerated over the past decade in countries at the lower end of the SDI range, while improvements have started to stagnate or even reverse in countries with higher SDI. Interpretation: As disability becomes an increasingly large component of disease burden and a larger component of health expenditure, greater research and developm nt investment is needed to identify new, more effective intervention strategies. With a rapidly ageing global population, the demands on health services to deal with disabling outcomes, which increase with age, will require policy makers to anticipate these changes. The mix of universal and more geographically specific influences on health reinforces the need for regular reporting on population health in detail and by underlying cause to help decision makers to identify success stories of disease control to emulate, as well as opportunities to improve. Funding: Bill & Melinda Gates Foundation. © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licens

Global age-sex-specific fertility, mortality, healthy life expectancy (HALE), and population estimates in 204 countries and territories, 1950-2019 : a comprehensive demographic analysis for the Global Burden of Disease Study 2019

Background: Accurate and up-to-date assessment of demographic metrics is crucial for understanding a wide range of social, economic, and public health issues that affect populations worldwide. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 produced updated and comprehensive demographic assessments of the key indicators of fertility, mortality, migration, and population for 204 countries and territories and selected subnational locations from 1950 to 2019. Methods: 8078 country-years of vital registration and sample registration data, 938 surveys, 349 censuses, and 238 other sources were identified and used to estimate age-specific fertility. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate age-specific fertility rates for 5-year age groups between ages 15 and 49 years. With extensions to age groups 10–14 and 50–54 years, the total fertility rate (TFR) was then aggregated using the estimated age-specific fertility between ages 10 and 54 years. 7417 sources were used for under-5 mortality estimation and 7355 for adult mortality. ST-GPR was used to synthesise data sources after correction for known biases. Adult mortality was measured as the probability of death between ages 15 and 60 years based on vital registration, sample registration, and sibling histories, and was also estimated using ST-GPR. HIV-free life tables were then estimated using estimates of under-5 and adult mortality rates using a relational model life table system created for GBD, which closely tracks observed age-specific mortality rates from complete vital registration when available. Independent estimates of HIV-specific mortality generated by an epidemiological analysis of HIV prevalence surveys and antenatal clinic serosurveillance and other sources were incorporated into the estimates in countries with large epidemics. Annual and single-year age estimates of net migration and population for each country and territory were generated using a Bayesian hierarchical cohort component model that analysed estimated age-specific fertility and mortality rates along with 1250 censuses and 747 population registry years. We classified location-years into seven categories on the basis of the natural rate of increase in population (calculated by subtracting the crude death rate from the crude birth rate) and the net migration rate. We computed healthy life expectancy (HALE) using years lived with disability (YLDs) per capita, life tables, and standard demographic methods. Uncertainty was propagated throughout the demographic estimation process, including fertility, mortality, and population, with 1000 draw-level estimates produced for each metric. Findings: The global TFR decreased from 2·72 (95% uncertainty interval [UI] 2·66–2·79) in 2000 to 2·31 (2·17–2·46) in 2019. Global annual livebirths increased from 134·5 million (131·5–137·8) in 2000 to a peak of 139·6 million (133·0–146·9) in 2016. Global livebirths then declined to 135·3 million (127·2–144·1) in 2019. Of the 204 countries and territories included in this study, in 2019, 102 had a TFR lower than 2·1, which is considered a good approximation of replacement-level fertility. All countries in sub-Saharan Africa had TFRs above replacement level in 2019 and accounted for 27·1% (95% UI 26·4–27·8) of global livebirths. Global life expectancy at birth increased from 67·2 years (95% UI 66·8–67·6) in 2000 to 73·5 years (72·8–74·3) in 2019. The total number of deaths increased from 50·7 million (49·5–51·9) in 2000 to 56·5 million (53·7–59·2) in 2019. Under-5 deaths declined from 9·6 million (9·1–10·3) in 2000 to 5·0 million (4·3–6·0) in 2019. Global population increased by 25·7%, from 6·2 billion (6·0–6·3) in 2000 to 7·7 billion (7·5–8·0) in 2019. In 2019, 34 countries had negative natural rates of increase; in 17 of these, the population declined because immigration was not sufficient to counteract the negative rate of decline. Globally, HALE increased from 58·6 years (56·1–60·8) in 2000 to 63·5 years (60·8–66·1) in 2019. HALE increased in 202 of 204 countries and territories between 2000 and 2019

Fonctionnalisation de nanopore unique par des polymères : conformation, transport et applications

Biological channels are proteins inserted in the cell membrane that keep ion equilibrium and ensure the molecule transport. These protein channels can respond to multiple stimuli like light, pH, ion strength and trans-membrane potential to regulate their permeability and selectivity. To mimic these biological pores, artificial nanopores have been has been developed on solid-state or polymer materials. The advantages of such artificial nanopores are simplicity of fabrication and mechanical, chemical stabilities. However the shortcomings are also clear that they usually have less selectivity and responsiveness to external stimuli. To enhance their properties, the functionalization is required in order to change their properties like permeability, selectivity or give them abilities to detect specific biomolecules.In this thesis, we aimed to functionalize track-etched nanopore with polymer for three applications: stimuli-responsive ion channel, osmotic energy harvesting and biosensing. For stimuli-responsive ion channel, we constructed two channels: one is functionalized by layer-by-layer self-assembly of various polyelectrolytes to respond to pH. The second one can respond to light and pH based on chemical grafting of spiropyran-PEG chains. Light induced isomerization and protonation/deprotonation caused by pH change can change the charge and conformation of functional molecules. Thus these changes can modulate ion perm-selectivity of the channel. For osmotic energy harvesting, we have followed two strategies to improve ion selectivity of membrane to get higher energy output. One used layer-by-layer depositing of polyelectrolytes on pore surface to enhance charge density. The other strategy used a high charged hydrogel synthesized inside the pore. Results showed a high energy generation for both two strategies of 20 pW per pore. The hydrogel functionalization makes it possible to use cylindrical geometry which is adequate for high pore density membrane. For biosensing application, we developed a PLL functionalized nanopore to detect oversulfated chondroitine sulfate (OSCS) contamination in heparin samples based on ionic diode principles. After being treated by heparinase, the heparin concentration in residue can quantitatively reflect the OSCS concentration based on ionic current rectification change. This experiment also confirmed the ability of track-etched nanopore to characterize the kinetics of enzymatic degradations. To go further, we immobilized hyaluronidases in the channel to characterize the enzymatic reactions at single molecule level using resistive pulse technique. The results showed that the duration of complexion between one hyaluronidase and one hyaluronic acid molecule for one reaction is around 1 second.In this thesis, we show the strong ability of polyelectrolytes functionalized track-etched nanopore. These well-designed systems can be easily scaled up and these well-developed principles can be used to design other systems to solve more problems in health and energy.Les canaux biologiques sont des protéines situées sur la membrane cellulaire. Ils permettent de maintenir l'équilibre des électrolytes et le transport des molécules. Ces canaux protéiques peuvent répondre à de multiples stimuli tels que la lumière, le pH, la force ionique et le potentiel transmembranaire afin de réguler leur perméabilité et leur sélectivité. Pour imiter ces pores biologiques, des nanopores artificiels ont été fabriqués des matériaux inorganiques ou polymères. Leurs avantages sont la simplicité de fabrication et leur stabilité mécanique et chimique. Cependant, ils sont généralement moins sélectifs et ne répondent pas aux stimuli externes. Pour améliorer leurs propriétés, leur fonctionnalisation est requise pour améliorer leurs propriétés de perméabilité, de sélectivité ou leur donner la capacité de détecter des biomolécules spécifiques.Dans cette thèse, nous avons cherché à fonctionnaliser des nanopores obtenus par la méthode des traces attaquée avec des polymères pour trois applications: mimer canal ionique sensible aux stimuli, la récupération de l’énergie osmotique et les biocapteurs. Pour mimer les canaux ioniques stimuli répondant, nous avons construit deux types de nanopore : l’un fonctionnalisé par auto-assemblage couche par couche de différent polyélectrolytes est sensible au pH. Le second est sensible à la lumière et au pH est obtenu par greffage chimique de Polyethylène glycol-spiropyran. L'isomérisation induites par la lumière et la protonation / déprotonation causées par le changement de pH peuvent modifier la charge et la conformation de molécules fonctionnelles modulant ainsi l’ouverture et la perm-sélectivité du pore. Pour la récupération d'énergie osmotique, nous avons suivi deux stratégies pour améliorer la sélectivité ionique de la membrane afin d’améliorer le rendement énergétique. La première approche consiste au dépôt couche par couche de polyélectrolytes sur la surface des pores pour augmenter la densité de charge de surface. La seconde stratégie est basée sur le remplissage sur pore par un hydrogel hautement chargé synthétisé in-situ. Les résultats ont montré une production d'énergie de 20 pW par pore pour les deux stratégies. La fonctionnalisation avec l’hydrogel permet d'utiliser une géométrie cylindrique permettant de fabriquer des membranes avec une haute densité de pores. Pour l’application biocapteur, , nous avons développé un nanopore fonctionnalisé par PLL afin de détecter la contamination de l’héparine par chodroitine sulfate oversulfatée (OSCS) en utilisant le principe de la diode ionique. Après avoir été traitée aux héparinases, la concentration en héparine dans les résidus peut refléter quantitativement la concentration en OSCS par la mesure de la rectification du courant ionique (ICR). Ces expériences ont aussi permis de confirmé la possibilité de caractériser la cinétique de dégradations enzymatiques par une nanopore unique. Pour aller plus loin, nous avons immobilisé des hyaluronidases dans le nanopore afin de caractériser les réactions enzymatiques au niveau d'une molécule à l'aide de la technique de pulse de résistance. Les résultats ont montré que la durée du complexe entre une hyaluronidase et une molécule d'acide hyaluronique pour une réaction est d'environ 1 seconde.Dans cette thèse, nous démontrons l’intérêt des nanopores obtenus par la technique des traces attaquée et fonctionnalisés par polyélectrolytes. Ces nanopore uniques peuvent être facilement reproduit et adapter pour concevoir d'autres systèmes pour des applications dans santé et d'énergie

Combining Light-Gated and pH-responsive nanopore based on PEG-spiropyran functionalization.

International audienc

Dynamics of long hyaluronic acid chains through conical nanochannels for characterizing enzyme reactions in confined spaces

International audienceThis research reports the transport behaviors of long flexible polymers (hyaluronic acid) through long conical track-etched nanochannels with and without grafted enzymes. The impacts of the channel diameter and the polymer regimes in solution (dilute and semi-dilute) have been investigated. Without enzymes, the experimental results can be well explained by the analytical models of the scaling law of de Gennes. Then, the corresponding enzymes (hyaluronidase) were grafted inside the channel. When enzymes are located at the base side, polymers get degraded at the entrance and the degraded products are detected. When enzymes are grafted at the tip side, the extension of translocation duration due to the binding of substrate-enzyme is observed. This is for the first time that the enzymatic degradation reactions are characterized in situ at the single molecule level by nanopore technology. † Electronic supplementary information (ESI) available: Experimental details, event distributions, etc

A Review on Heat Transfer Enhancement of Phase Change Materials Using Fin Tubes

Latent heat thermal energy storage (LHTES) has received more and more attention in the thermal energy storage field due to the large heat storage density and nearly constant temperature during phase change process. However, the low thermal conductivity of phase change material (PCM) leads to poor performance of the LHTES system. In this paper, the research about heat transfer enhancement of PCM using fin tubes is summarized. Different kinds of fins, such as rectangular fin, annular fin, spiral fin, etc., are discussed and compared based on the shape of the fins. It is found that the longitudinal rectangular fins have excellent heat transfer performance and are easy to manufacture. The effect of fins on heat transfer enhancement is closely related to the number of fins and its geometric parameters

Single conical track-etched nanopore for a free-label detection of OSCS contaminants in heparin

International audienceThe heparin contamination by oversulfated chondroitin (OSCS) was at the origin of one major sanitary problem of last decade. Here we propose a novel strategy to detect OSCS from heparin solution based on conical nanopore functionalized with poly-L-lysine deposition to ensure its re-usability. This sensor is an excellent to detect low heparin concentration (from 25 ng/ml to 3 mu g/ml) using the modification of ionic current rectification. It also allows following the kinetic of heparin degradation by heparinase with a good correlation with results obtained by classical methods. The sensor is sensitive to the inhibition of heparinase by OSCS until a concentration of 200 pg/l representing 0.01% in weight in a heparin. This resolution is one order of magnitude lower than the one obtained by chromatography. For the first time, it was reached without fluorescence labelin