Study on the Comparison of Three Typical Gas Flow Standards for Calibrating Low Gas Flowmeter

A gas flowmeter for measuring low flow rate has been widely used in the field of medical, health, environmental protection, energy industry, aerospace, etc. To against Covid-2019, the requirement on the low flow rate has been increasing dramatically. At present, the typical standard devices for calibrating low gas flowmeter mainly include standard bell provers of gas flow, standard piston provers of low gas flow and standard laminar of low gas flow. Different measuring principles are adopted among these typical standard devices. To ensure the consistency of these typical standard devices, a comparison test is performed. The standard devices used in the comparison are of the same accuracy grade, with an extended uncertainty of 0.2%(k=2). The piston-type gas flow calibrator of grade 1.0 is selected as the transfer standard, and three flow points with high flow rate, medium flow rate and low flow rate are selected for test. The consistency of measurement results is evaluated by normalized deviation En. The comparison results are acceptable which show that three typical standard devices are accurate and reliable. © FLOMEKO 2022.All rights reserved

Winter-autumn air pollution control plan in North China modified the PM2.5 compositions and sources in Central China

The additional impact of emission-reduction measures in North China (NC) during autumn and winter on the air quality of downwind regions is an interesting but less addressed topic. The mass concentrations of routine air pollutants, the chemical compositions, and sources of fine particles (PM2.5) for January 2018, 2019, and 2020 at a megacity of Central China were identified, and meteorology-isolated by a machine-learning technique. Their variations were classified according to air mass direction. An unexpectedly sharp increase in emission-related PM2.5 by 22.7% (18.0 mug m-3) and 25.7% (19.4 mug m-3) for air masses from local and NC in 2019 was observed compared to those of 2018. Organic materials exhibited the highest increase in PM2.5 compositions by 6.90 mug m-3 and 6.23 mug m-3 for the air masses from local and NC. PM2.5 source contributions related to emission showed an upsurge from 1.39 mug m-3 (biomass burning) to 24.9 mug m-3 (secondary inorganic aerosol) in 2019 except for industrial processes, while all reduced in 2020. From 2018 to 2020, the emission-related contribution of coal combustion to PM2.5 increased from 10.0% to 19.0% for air masses from the local area. To support the priority natural gas quotas in northern China, additional coal in cities of southern China was consumed, raising related emissions from transportation activities and road dust in urban regions, as well as additional biofuel consumption in suburban or rural regions. All these activities could explain the increased primary PM2.5 and related precursor NO2. This study gave substantial evidence of air pollution control measures impacting the downwind regions and promote the necessity of air pollution joint control across the administration.Copyright © 2023 Elsevier Ltd

SERS/photothermal-based dual-modal lateral flow immunoassays for sensitive and simultaneous antigen detection of respiratory viral infections

Lateral flow immunoassay (LFIA) is one of the most common analytical platforms for point-of-care testing (POCT), which is capable of large-scale primary screening and home self-testing of infectious diseases. However, the sensitivity of conventional AuNPs-based LFIA is relatively low and more prone to false negatives. Herein, we report a novel LFIA based on gold-core-silver-shell bimetallic nanoparticles (Au4-ATP@Ag NPs) emitting Surface-enhanced Raman scatting (SERS) and Photothermal (PT) effect, named SERS/PT-based dual-modal LFIA (SERS/PT-dmLFIA), for the antigen detection of infectious diseases pathogens, which displayed an excellent performance. For influenza A virus (IAV), influenza B virus (IBV), and Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) N protein detection, the limit of detections (LoD) with Raman as signal were 31.25, 93.75, and 31.25 pg mL-1 respectively, and the LoDs with temperature difference (∆T) as signal were as low as 15.63, 187.5, and 15.63 pg mL-1 respectively, which were over 4-fold more sensitive than visual-based LFIA. The proposed SERS/PT-dmLFIA was used for detecting virus antigen in pharyngeal swabs and showed ideal coincidence rate of over 95% compared to the commercialized assays. In addition, we explored the development of multiplex SERS/PT-dmLFIA that can detect IAV, IBV, and SARS-CoV-2 antigens simultaneously without cross reactivity. Overall, the SERS/PT-dmLFIA for antigen detection not only exhibits high sensitivity, accuracy and specificity, but also have characteristics of rapidity and simplicity, which holds high potential for rapid diagnosis of infectious diseases in laboratory testing, mass screening, and home self-testing. © 2023 Elsevier B.V.

Disparities in Chronic Kidney Disease Risks: Data from the Cure-Ckd Covid-19 Registry

Introduction: The SARS-CoV-2 pandemic accelerated health disparities in chronic kidney disease (CKD). Here, we describe risk factors and access to care surrogates (area deprivation index-ADI) for clinical outcomes among SARS-CoV-2-tested patients in the Center for Kidney Disease Research, Education, and Hope (CURE-CKD) Registry. Method(s): We formed a COVID-19 Sub-Registry within CURE-CKD (1/1-6/30/2021;N=171,988) of patients with CKD, diabetes (DM)/pre-DM, or hypertension (HTN) with SARS-CoV-2 testing at UCLA Health (UCLA;N=17,884) and Providence St. Joseph Health (PSJH;N=154,104). Statistical analyses and fitted multivariable logistic regression models were adjusted for age and sex. The UCLA cohort included analyses for acute kidney injury (AKI), area deprivation index (ADI, for poor housing, education, income), Charlson Comorbidity Index (CCI), and severe COVID-19 disease. Result(s): We determined the odds ratios and 95% confidence interval (OR[95%CI[) of COVID-19 positivity for the combined UCLA + PSJH population, as well as OR of having severe COVID-19 disease in the UCLA cohort (Table 1) only. OR[95%CI] for AKI was higher for ages >=80 years (1.77[1.14-2.46]), ADI by state (1.12[1.06-1.18]), CKD (12.20[8.46-17.58]) and pre-existing DM (3.65[2.62-5.08]), p<0.001. In the UCLA CURE-CKD population, AKI was associated with severe COVID-19 (r=0.26) and ICU admissions (r=0.29). Mortality was associated with severe COVID-19 disease (r=0.5). [Formula presented] Conclusion(s): Non-White and/or LatinX race/ethnicity, ADI, CKD, DM, and older age were associated with higher risks of COVID-19 positivity, disease severity, and mortality in CURE-CKD. Efforts on viral screening, timely COVID-19 diagnosis, and optimal care delivery for patients with or at-risk of CKD are needed. Conflict of interest Potential conflict of interest: SBN is supported by NIH research grants R01MD014712, RF00250-2022-0038, U2CDK129496 and P50MD017366, and CDC project number 75D301-21-P-12254 receives research support from Bayer AG for the submitted work, Goldfinch Bio, Travere and Terasaki Institute of Biomedical Innovation, and personal fees and other support from AstraZeneca, Bayer AG, Gilead, NovoNordisk and Boehringer Ingelheim/Lilly. KBD is supported by an NIH research grant R01MD014712 and CDC project number 75D301-21-P-12254 and reports other support from Bayer AG for the submitted work, and Goldfinch Bio and Travere outside the submitted work. CRJ is supported by an NIH research grant R01MD014712 and CDC project number 75D301-21-P-12254 and reports other support from Bayer AG for the submitted work, and Goldfinch Bio and Travere outside the submitted work. KCN is supported in part by NIH research grants UL1TR001881, P30AG021684, U2CDK129496 and P50MD017366. KRT is supported by NIH research grants R01MD014712, U2CDK114886, UL1TR002319, U54DK083912, U01DK100846, OT2HL161847, UM1AI109568 and CDC project number 75D301-21-P-12254 and reports other support from Eli Lilly personal fees and other support from Boehringer Ingelheim personal fees and other support from AstraZeneca grants, personal fees and other support from Bayer AG grants, personal fees and other support from Novo Nordisk grants and other support from Goldfinch Bio other support from Gilead and grants from Travere outside the submitted work.Copyright © 2023

COVID-19 Detection Algorithm Combining Grad-CAM and Convolutional Neural Network

In the detection of COVID-19, chest X-ray (CXR) images and CT scan images are two main technical methods, which provide an important basis for doctors' diagnosis. Currently, convolutional neural network (CNN) in detecting the COVID-19 medical radioactive images has problems of low accuracy, complex algorithms, and in¬ability to mark feature regions. In order to solve these problems, this paper proposes an algorithm combining Grad-CAM color visualization and convolutional neural network (GCCV-CNN). The algorithm can quickly classify lung X-ray images and CT scan images of COVID-19-positive patients, COVID-19-negative patients, general pneu¬monia patients and healthy people. At the same time, it can quickly locate the critical area in X-ray images and CT images. Finally, the algorithm can get more accurate detection results through the synthesis of deep learning algo¬rithms. In order to verify the effectiveness of the GCCV-CNN algorithm, experiments are performed on three COVID- 19-positive patient datasets and it is compared with existing algorithms. The results show that the classification per¬formance of the algorithm is better than the COVID-Net algorithm and the DeTraC-Net algorithm. The GCCV-CNN algorithm achieves a high accuracy of 98.06%, which is faster and more robust. © 2022, Journal of Computer Engineering and Applications Beijing Co., Ltd.;Science Press. All rights reserved.

Procedures of prevention and control of COVID-19 during X-ray imaging examinations in Jiangsu province.

X-ray imaging is an important method for the diagnosis of corona virus disease(COVID-19), but there is a risk of nosocomial infection during X-ray imaging and diagnosis. By analyzing the process of X-ray imaging & diagnosis and the possible exposure factors in hospital, Jiangsu province took the lead in issuing the guideline for the nosocomial infection prevention and control of COVID-19 during X-ray imaging and diagnosis. This guideline clarifies the basic requirements for controlling infections during X-ray imaging and diagnosis, the specific measures for staff protection, disinfection of personnel and sites, and the protection and disinfection of subjects, which is instructive for on-site work. It is worth noting that while focusing on controlling infections, the principle of optimal protection for medical exposure cannot be ignored.Copyright © 2020 by the Chinese Medical Association.

COVID-19 Detection Algorithm Combining Grad-CAM and Convolutional Neural Network

In the detection of COVID-19, chest X-ray (CXR) images and CT scan images are two main technical methods, which provide an important basis for doctors' diagnosis. Currently, convolutional neural network (CNN) in detecting the COVID-19 medical radioactive images has problems of low accuracy, complex algorithms, and in¬ability to mark feature regions. In order to solve these problems, this paper proposes an algorithm combining Grad-CAM color visualization and convolutional neural network (GCCV-CNN). The algorithm can quickly classify lung X-ray images and CT scan images of COVID-19-positive patients, COVID-19-negative patients, general pneu¬monia patients and healthy people. At the same time, it can quickly locate the critical area in X-ray images and CT images. Finally, the algorithm can get more accurate detection results through the synthesis of deep learning algo¬rithms. In order to verify the effectiveness of the GCCV-CNN algorithm, experiments are performed on three COVID- 19-positive patient datasets and it is compared with existing algorithms. The results show that the classification per¬formance of the algorithm is better than the COVID-Net algorithm and the DeTraC-Net algorithm. The GCCV-CNN algorithm achieves a high accuracy of 98.06%, which is faster and more robust. © 2022, Journal of Computer Engineering and Applications Beijing Co., Ltd.;Science Press. All rights reserved.

An Update Review of the Pathogenesis Hypothesis in Preeclampsia

Objectives: Hypertensive disorders occur in approximately 12% to 22% of pregnancies and cause substantial perinatal morbidity and mortality of both mother and fetus. Hypertensive disease is directly responsible for approximately 20% of maternal deaths and can be classified as chronic hypertension, gestational hypertension, preeclampsia-eclampsia, and chronic hypertension with superimposed preeclampsia. At present, the pathogenesis of preeclampsia is still unclear, we wrote this article to make a uptodate review of this disease. Mechanism: A comprehensive search of several databases was conducted from inception up to March 2022. The searched databases were Web of Science, MEDLINE, Ovid, and Cochrane Database of Systematic Reviews. The search strategy included the combinations of the following medical terms: Hypertensive disorders;preeclampsia;mechanism;pathogenesis hypothesis. Findings in Brief: At present, the pathogenesis of preeclampsia is still unclear, the theory of Genetic, Inflammatory Response, Immune Imbalance in Maternal-Fetal Interface, Oxidative Stress, Vascular Endothelial Cell Damage are supposed involved in the progress of preeclampsia. Conclusions: Although there are various theories mentioned above, none of the hypothesis can fully explain preeclampsia. More research is needed on the mechanism of preeclampsia.

The defects of lace-up surgical masks and related solutions in operating rooms.

BACKGROUND: It is difficult to make a lace-up surgical mask fit tightly to the face with conventional wearing methods because of the strings' poor tension, resulting in some air flowing through the gap. We introduced two feasible new wearing methods and obtained satisfactory experimental results. METHODS: The wearing of surgical masks by staff was investigated through observation and interview in operation rooms. The required time to don, close-fitting rates, and satisfaction of the conventional method and the two new recommended methods were counted and compared, according to the subjects' experience. The differences between the three wearing methods on the microbial contamination of the sterile area were explored in a mock operation. RESULTS: In the subjects' experience, the close-fitting rates were 47.0%, 92.0% and 100.0% in the conventional, Three Knots, and Elastic Band groups, respectively (P<0.001); the satisfaction scores evaluated by numerical rating scale from 0 to 10 were 5.06 ± 2.22, 6.89 ± 1.86 and 7.10 ± 1.72, respectively (P<0.001); the required times were 14.32 ± 2.20, 25.76 ± 5.13 and 27.37 ± 5.11 s, respectively (P<0.001). In the mock operation, there were significant differences between the conventional and Three Knots groups (37.5 (13) vs 18 (8) cfu, P<0.001), as well as between the conventional and Elastic Band groups (37.5 (13) vs 17(10) cfu, P<0.001). CONCLUSIONS: The recommended new wearing methods had the advantages of closer fit, higher satisfaction rates, were more comfortable, and resulted in lower contamination of the sterile area; however, the recommended two methods required more time.

Online Consumption Under Pandemic: Stress, Cognitive Appraisal, Coping Style, Normative Social Influences, and Risk Averse

Malaysia government imposed stay-at-home ruling during COVID-19 pandemic. The pandemic and stay-at-home ruling created stress to the Malaysian consumers. Some consumers turned to online platform for purchase of food and home essential. This study aims to investigate the impacts of pandemic stress, cognitive appraisal, coping style, online normative social influences, and risk averse on the changes in online planned consumption behaviors. Theory of Stress and Coping is used to develop a research framework to examine the planned consumption behavior in this study. Quantitative research with survey questionnaire is used to collect data. Data collected was analyzed with PLS-SEM. Findings confirmed that stress trigger cognitive appraisal, however cognitive appraisal of emotion only related to emotional coping style. Physical coping style, normative social influences and risk averse predicted planned online consumption behavior. This study provided bother academic and managerial implications in the context on consumer consumption behavior. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.

Global patterns of daily CO2 emissions reductions in the first year of COVID-19

Observed daily changes in CO2 emissions from across the globe reveal the sectors and countries where pandemic-related emissions declines were most pronounced in 2020. Day-to-day changes in CO2 emissions from human activities, in particular fossil-fuel combustion and cement production, reflect a complex balance of influences from seasonality, working days, weather and, most recently, the COVID-19 pandemic. Here, we provide a daily CO2 emissions dataset for the whole year of 2020, calculated from inventory and near-real-time activity data. We find a global reduction of 6.3% (2,232 MtCO(2)) in CO2 emissions compared with 2019. The drop in daily emissions during the first part of the year resulted from reduced global economic activity due to the pandemic lockdowns, including a large decrease in emissions from the transportation sector. However, daily CO2 emissions gradually recovered towards 2019 levels from late April with the partial reopening of economic activity. Subsequent waves of lockdowns in late 2020 continued to cause smaller CO2 reductions, primarily in western countries. The extraordinary fall in emissions during 2020 is similar in magnitude to the sustained annual emissions reductions necessary to limit global warming at 1.5 degrees C. This underscores the magnitude and speed at which the energy transition needs to advance.

[Characteristics of liver function changes in 111 elderly patients with COVID-19 pneumonia].

Objective: To retrospectively analyze the characteristics and influencing factors of liver function changes in 111 elderly patients with COVID-19 pneumonia. Methods: 111 elderly patients with COVID-19 admitted to the Department of Infectious Diseases, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology from February 5 to March 3, 2020 were enrolled. According to the severity of disease and liver function condition, they were divided into severe group (n=40), normal group (n=71), abnormal liver function group (n=86) and normal liver function group (n=25). The indexes related to liver function changes [total bilirubin (TBil), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and γ-glutamyl transferase (GGT)] and related influencing factors were analyzed. Results: Among 111 cases, 86 (77.5%) had abnormal liver function of varying degrees, and 28 (25.2%) had liver injury. The abnormal rates of TBil, AST, ALP and GGT were significantly higher in the severe group than normal group (P<0.05). There were no significant differences in age, ribavirin, glucocorticoid and the application of lopinavir-ritonavir tablets between the abnormal liver function and the normal group (P>0.05). The proportion of male was significantly higher in the abnormal liver function than normal liver function group (P<0.05). Conclusion: Elderly COVID-19 patients have a higher proportion of abnormal liver function, and patients in the severe group are more likely to have higher level of TB, AST, ALP and GGT. The abnormal liver function may be related to the direct viral infection of the liver and the inflammatory immune response of the body after infection in elderly patients.

Research progress on the BCG-induced trained immunity:mechanism and role

The purpose of Bacillus Calmette-Guérin (BCG) vaccination is to prevent Mycobacterium tuberculosis infection, but studies have shown that BCG activates innate immunity, causes epigenetic reprogramming and metabolic changes of myeloid cells, and forms innate immune memory or trained immunity. When bone marrow-like cells are stimulated by pathogens again, they show enhanced immune response and promote the host's nonspecific defense ability. Innate immune memory is also called training immunity. In recent years, BCG-induced innate immune memory has attracted much attention, and it will guide the design of novel vaccine. This article reviews the application of BCG in prevention and treatment of corone virus disease 2019, the non-specific protection and mechanism of BCG-mediated trained immunity.

An Ultra-Sensitivity Cancellation Type Sensor Based on Microstrip Meander-Line

The analysis of dielectric properties in Novel Coronavirus (COVID-19) has become an important research branch since the outbreak of the epidemic in 2019. In order to detect the dielectric properties of microfluidics like virus with higher sensitivity, a radio frequency sensor model is proposed in this paper. First, based on the excellent characteristics of the microstrip meander-line such as more concentrated electric field distribution, the microstrip meander-line is introduced into the design of traditional cancellation sensor, which is called the meander sensor. Then, the relationship between transmission coefficients of the system and dielectric properties of microfluidics is given in this paper. The simulation results verify the ultra-sensitivity of the meander sensor. Even though the relative permittivity of microfluidics is changed in the order of magnitude 10-2, the measurement results of the meander sensor also change significantly. However, the straight sensor can only measure changes of relative permittivity in the order of magnitude 10-1. What's more, there is a more concentrated measurement range for the meander sensor. This will be more practical for measuring weak changes of dielectric properties caused by the microfluidics itself and its interactions. © 2021 IEEE.

The Right to Accessible COVID-19 Testing in the Post-Epidemic Period under the Urban-Rural Integration: Haishu District, Ningbo City, China

The reasonable distribution of COVID-19 testing facilities is a crucial public necessity to protect the civil right of health and the proper functioning of society in the post-epidemic period. However, most of the current COVID-19 testing facilities are in large hospitals in China, partially overlooking the COVID-19 testing needs of rural dwellers. This paper used shortest-path analysis and the improved potential model to measure the accessibility of current and potential COVID-19 testing facilities, superimposing this with the testing demands of residents, as calculated by the population demand index, so as to comprehensively evaluate the equity of the spatial allocation of the current and potential testing facilities, with a particular focus on Haishu District, Ningbo City, China. The results revealed that the overall accessibility of the current testing facilities in Haishu District was high, while the internal spatial differentiation was considerable. The comprehensive accessibility of testing facilities gradually declined from the downtown areas towards the rural areas. Moreover, roughly half of the rural population needing COVID-19 tests encountered hindrances due to poor access to testing agencies. However, after fully exploiting the potential testing facilities, the comprehensive accessibility of testing facilities was significantly improved, and the inequity in the accessibility to testing facilities was effectively alleviated, which significantly improved the equity of the allocation of testing facilities in Haishu District. The leveraging of current medical facilities to boost the number of testing facilities in rural areas could eliminate the disparity of resource distribution caused by urban and rural binary opposition, and could quickly identify external sources of COVID-19 in rural areas in the post-epidemic period. Moreover, efficient COVID-19 testing combined with the travel records of infection carriers can effectively identify unknown infection cases and obviate large-scale infection outbreaks.

The Seesaw Pattern of PM2.5 Interannual Anomalies Between Beijing-Tianjin-Hebei and Yangtze River Delta Across Eastern China in Winter

Since 2013, the winter mean fine particulate matter (PM2.5) had been decreased significantly due to stringent emission controls in most of China. Nevertheless, we found a seesaw pattern of PM2.5 interannual anomalies between Beijing-Tianjin-Hebei (BTH) and Yangtze River Delta (YRD). Using the multiple linear regression method, meteorology-driven PM2.5 interannual anomalies show that the low (high) PM2.5 relative difference between BTH and YRD (RDB&Y) was associated with the strong (weak) East Asian winter monsoon (EAWM). The strong EAWM transported more air pollutants from BTH to YRD. During the COVID-19 lockdown period, due to the weak EAWM, air pollution still occurred in northern BTH, while the PM2.5 was relatively low in YRD, causing high RDB&Y values. Our results imply that the activity of EAWM and characteristics of regional transport have obvious interannual variations, which is indispensable in evaluating the achievements of PM2.5 quality management between up and downstream regions.

Disparities in CKD risks: Data from the cure-CKD COVID-19 sub-registry

Background: The SARS-CoV-2 pandemic accelerated health disparities in chronic kidney disease (CKD). Here, we describe risk factors and access to care surrogates (area deprivation index-ADI) for clinical outcomes among SARS-CoV-2-tested patients in the CURE-CKD Registry. Methods: We formed a COVID-19 Sub-Registry within CURE-CKD (1/1-6/30/2021;N=171,988) of patients with CKD, diabetes (DM)/pre-DM, or hypertension (HTN) with SARS-CoV-2 testing at UCLA Health (UCLA;N=17,884) and Providence St. Joseph Health (PSJH;N=154,104). Statistical analyses and fitted multivariable logistic regression models were adjusted for age and sex. The UCLA cohort included analyses for acute kidney injury (AKI), ADI (for poor housing, education, income), Charlson Comorbidity Index (CCI), and severe COVID-19 disease. Results: Odds ratios (OR) of COVID-19 positivity for the combined UCLA + PSJH population, as well as OR of having severe COVID-19 disease in the UCLA cohort are presented (Table). OR[95%CI] for AKI were higher for ages ≥80 years (1.77[1.14-2.46]), ADI by state (1.12[1.06-1.18]), CKD (12.20[8.46-17.58]) and pre-existing DM (3.65[2.62-5.08]), p<0.001. In the UCLA CURE-CKD population, AKI was associated with severe COVID-19 (r=0.26) and ICU admissions (r=0.29). Mortality was associated with severe COVID-19 disease (r=0.5). Conclusions: Non-White and/or LatinX race/ethnicity, ADI, CKD, DM, and older age were associated with higher risks of COVID-19 positivity, disease severity, and mortality in CURE-CKD. Efforts on viral screening, timely COVID-19 diagnosis, and optimal care delivery for patients with or at-risk for CKD are needed.

The paradox of negative oil prices

2020 is definitely a year that will be remembered in history. The global outbreak of the COVID-19 pandemic has caused a huge impact on the global economy, in particular, the paradox of negative oil prices, which has raised huge challenges in the practice of commodity and related asset risk management. © 2021 World Scientific Publishing Company.