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1.
European Journal of Human Genetics ; 31(Supplement 1):706, 2023.
Artigo em Inglês | EMBASE | ID: covidwho-20244996

RESUMO

Background/Objectives: The broad spectrum of clinical manifestations from SARS-COV-2 infection and observed risk factors for severe disease highlight the importance of understanding molecular mechanisms underlying SARS-CoV-2 associated disease pathogenesis. Research studies have identified a large number of host proteins that play roles in viral entry, innate immune response, or immune signalling during infection. The ability to interrogate subsets of these genes simultaneously within SARSCOV-2 infected samples is critical to understanding how their expression contribute to phenotypic variability of the disease caused by the pathogen. Method(s): 30 Nasopharyngeal swab were obtained and included SARS-CoV-2 infected and control samples. RNA was extracted, reverse transcribed and loaded onto flexible TaqMan array panels designed specifically for targeting the most cited genes related to SARS-COV-2 entry and restriction factors as well as cytokines, chemokines, and growth factors involved in the pathogenesis. Result(s): Our data indicated that not only were the levels of several of these host factors differentially modulated between the two study groups, but also that SARS-CoV-2 infected subjects presented with greater frequency of several important inflammatory cytokines and chemokines such as CCL2, CCL3, IFNG, entry receptors such as ACE2, TMRPS11A, and host restriction factors including LY6E and ZBP1. Conclusion(s): TaqMan array plates provide a fast, midthroughput solution to determine the levels of several virus and host-associated factors in various cell types and add to our understanding of how the pathogenesis may vary depending on gender, age, infection site etc.

2.
Land ; 12(5), 2023.
Artigo em Inglês | Web of Science | ID: covidwho-20244995

RESUMO

We employed publicly available user-generated content (UGC) data from the website Tripadvisor and developed an autoregressive integrated moving average (ARIMA) model using the R language to analyze the seasonality of the use of urban green space (UGS) in Okinawa under normal conditions and during the COVID-19 pandemic. The seasonality of the use of ocean-area UGS is primarily influenced by climatic factors, with the peak season occurring from April to October and the off-peak season from November to March. Conversely, the seasonality of the use of non-ocean-area UGS remains fairly stable throughout the year, with a relatively high number of visitors in January and May. The outbreak of the COVID-19 pandemic greatly impacted visitor enthusiasm for travel, resulting in significantly fewer actual postings compared with predictions. During the outbreak, use of ocean-area UGS was severely restricted, resulting in even fewer postings and a negative correlation with the number of new cases. In contrast, for non-ocean-area UGS, a positive correlation was observed between the change in postings and the number of new cases. We offer several suggestions to develop UGS management in Okinawa, considering the opportunity for a period of recovery for the tourism industry.

3.
Journal of Marketing for Higher Education ; : 1-32, 2023.
Artigo em Inglês | Web of Science | ID: covidwho-2327209

RESUMO

Studies have been conducted on university students' acceptance of e-learning systems during COVID-19. However, less attention has been paid to students' use of e-learning post-pandemic. This research provides a more comprehensive framework to investigate the effects of e-learning students' various quality perceptions on attitude, learning engagement, and stickiness toward e-learning platforms. A survey-based quantitative method is adopted by this study in which sample data are collected from students in Australian universities. A total of 403 valid samples were analysed using covariance-based structural equation modelling. This study found that students' perceived educational quality, service quality, information quality, and technical system quality play different roles in their attitudes and behaviours towards e-learning. It expands the information system success model by comparing the effects of students' various perceived qualities on their ongoing commitment to e-learning. It provides insights to e-learning providers in pursuing better designs and more sustainable development of educational information systems.

4.
European Journal of Inflammation ; 20, 2022.
Artigo em Inglês | Web of Science | ID: covidwho-2311328

RESUMO

The purpose of this study was to investigate the expression of pyroptosis-related factors (NLRP3, IL-18, NF-kappa B, HMGB-1, and GSDMD) in patients who died of COVID-19. The expression levels of NLRP3, IL-18, NF-kappa B, HMGB-1, and GSDMD in lung and spleen tissues of the COVID-19 group and the control group were detected by tissue immunofluorescence. The control group includes lung tissues and spleen tissues of two patients who died unexpectedly without SARS-CoV-2 infection, and the COVID-19 group includes the lung and spleen tissues of three patients who died of SARS-CoV-2 virus infection. The positive rates of NF-kappa B, NLRP3, IL-18, and GSDMD in the lung tissues from the control group and COVID-19 group were 9.8% vs 73.4% (p = 0.000), 5.5% vs 63.6% (p = 0.000), 24.4% vs 76.2% (p = 0.000), and 17.5% and 46.8% (p = 0.000) respectively. The positive rates of NF-kappa B, NLRP3, IL-18, HMGB-1, and GSDMD in the spleen tissues from the control group and COVID-19 group were 20.6% vs 71.2% (p = 0.000), 18.9% vs 72.0% (p = 0.000), 15.2% vs 64.8% (p = 0.000), 27.6% vs 69.2% (p = 0.000), and 23% and 48.8% (p = 0.000), respectively. The positive rates of SARS-CoV-2 spike protein in the CD68 positive cells of the lung and spleen in the control group and COVID-19 group were 2.5% vs 56.8% (p = 0.000);3.0% vs 64.9% (p = 0.000) respectively. The rates of NF-kappa B positive nuclei in the control group and COVID-19 group were 13.4% vs 51.4% (p = 0.000) in the lung and 38.2% vs 59.3% (p = 0.000) in the spleen. The rates of HMGB-1 positive cytoplasm in the control and the COVID-19 group were 19.7% vs 50.3% (p = 0.000) in the lung and 12.3% vs 45.2% (p = 0.000) in the spleen. The targets of SARS-CoV-2 are the lung and spleen, where increased macrophages could be involved in the up-regulation of pyroptosis-related inflammatory factors such as NF-kappa B, HMGB-1, NLRP3, IL-18, and GSDMD.

5.
European Respiratory Journal Conference: European Respiratory Society International Congress, ERS ; 60(Supplement 66), 2022.
Artigo em Inglês | EMBASE | ID: covidwho-2276120

RESUMO

Introduction: Covid-19 increased the burden on hospitals for patients with symptoms and potential vital complications. Patient home self-monitoring of clinical signs and physiological safety parameters using connected devices was assessed to better detect patients with indication of rehospitalization. Method(s): After clinical/PCR COVID confirmation, patients were given WITHINGS devices: Scanwatch, a thermometer, a blood pressure monitor, a Sleep analyzer and instructed to take measures twice a day with data retrieved on HealthMate app. Reports and questionnaires on clinical symptoms were sent daily to physicians. Result(s): Ten PCR positive patients were included (5 males): mean age 45.5years [31;67], BMI 26.9kg/m2 [19.7;43.2]. Main COVID symptoms were cough (33%), sore throat (27%), tiredness (36%), dyspnea (37%). Delay between COVID onset and self-monitoring start was 7.7days [0-37]. 8 patients had a good adherence to the protocol up to 30 days. SpO2 and Heart Rate (HR) were most frequently measured: 88 [5-177] and 58 [21-195] measures in average respectively. Five patients with polysomnography had Apnea-Hypopnea Index (AHI) equivalent to the Sleep analyzer averaged over several nights: AHISA: 8.53[-1;71.4] vs AHIPSG: 13.01[1.49;28.76]. Temperature remained within normal in 9/10 patients. In most patients Breathing rate (BR) decreased, HR decreased or remained steady, nigthtime HR/BR changed similarly. Daily steps increased throughout along with BR reduction. All patients had favorable outcomes without indication of hospitalization. Conclusion(s): Home self-monitoring during a pandemic is feasible. Safety parameters may be effectively monitored by patients and easily reported to their physicians.

6.
Chinese General Practice ; 26(10):1234-1240, 2023.
Artigo em Chinês | Scopus | ID: covidwho-2263408

RESUMO

【】 Background COVID-19 may impair the central nervous system,but the prevalence and related factors of very early cognitive impairment in discharged COVID-19 convalescents are still unclear. Objective To assess the prevalence of very early cognitive impairment in discharged COVID-19 convalescents,and to identify its influencing factors. Methods This study included 574 COVID-19 convalescents from August 28 to September 30,2020,including individuals who were discharged from designated hospitals for treating COVID-19 in Wuhan from December 2019 to April 2020 randomly selected from the hospital information system,and those with informed consent recruited through news media. According to the Eight-item Informant Interview to Differentiate Aging and Dementia(AD8)score,the subjects were divided into a very early cognitive impairment group(AD8 ≥ 2)and a non-very early cognitive impairment group(AD8<2). A questionnaire survey was conducted with the subjects by four investigators at Hubei Provincial Hospital of Traditional Chinese &amp;Western Medicine,using the General Information Questionnaire to collect demographic information and past disease history of the patients(including gender,age,underlying disease,classification of COVID-19 on admission,interval between discharge and the current survey,and various symptoms present at the time of follow-up),using the Generalized Anxiety Disorder-7(GAD-7),the PTSD Check List–Civilian Version(PCL-C),and the Short Form 36 Health Survey Questionnaire(SF-36)to assess patients' anxiety,post-traumatic stress disorder,and quality of life,respectively. Three hundred and eleven cases finally completed the cognitive function screening. Multiple Logistic regression was used to evaluate the effects of gender,age,underlying disease and admission classification of COVID-19 on very early cognitive impairment. A restricted cubic spline model was used to assess the quantitative relationship between anxiety level and very early cognitive impairment. Results 311(54.18%)who effectively responded to the survey was finally enrolled,including 170(54.7%)with very early cognitive impairment and 141(45.3%)without. 230 (23.9%)had residual symptoms after discharge. Comparisons of gender,age,insomnia,fatigue,chest tightness,shortness of breath,loss of appetite,generalized anxiety disorder,PTSD positive,and the score of each SF-36 entry among COVID-19 convalescents with and without very early cognitive impairment were statistically significant(P<0.05). Multivariate Logistic regression analysis suggested that females〔OR(95%CI)=2.658(1.528,4.625)〕,advanced age〔OR(95%CI)=3.736(1.083,12.890)〕,and having generalised anxiety disorder〔OR(95%CI)=5.081(1.229,21.008)〕were influential factors in increasing very early cognitive impairment(P<0.05). Restricted cubic spline models indicated a linear quantitative relationship between anxiety level and very early cognitive impairment,with higher levels of anxiety associated with a greater likelihood of very early cognitive impairment(P for non-linear test =0.132). Conclusion The incidence of very early cognitive impairment is high in COVID-19 convalescents,and it may be higher in those who are older,female,or have generalized anxiety symptoms. Timely interventions for psychiatric problems and alleviation of anxiety symptoms in COVID-19 convalescents,especially in older women,may help to improve their cognitive function and Alzheimer's disease. © 2023 Chinese General Practice. All rights reserved.

7.
15th International Congress on Image and Signal Processing, BioMedical Engineering and Informatics, CISP-BMEI 2022 ; 2022.
Artigo em Inglês | Scopus | ID: covidwho-2213166

RESUMO

Intramuscular (IM) injection is mainly performed manually at present. Large-scale COVID-19 vaccination has exposed various problems of manual IM injection. In addition, the clinical success rate of manual IM injection is also unsatisfactory. Using robotic intramuscular injection system (RIMIS) is expected to realize automated vaccination and improve the success rate of IM injection. The existing robotic needle insertion system based on image guidance is not a practical option for IM injection because of the time-consuming medical imaging process. In this paper, an optical guidance method for RIMIS is proposed, which uses near-infrared optical tracking system and retro-reflective patch to achieve rapid acquisition of surface normal vector. A closed loop formed by six coordinate systems is used to realize the accurate control of the injection angle and depth. Experimental results show that the RIMIS based on the proposed method can complete the simulated IM injection operation without image guidance and possess accurate control of the injection angle and depth. © 2022 IEEE.

8.
Supply Chain Management ; 2023.
Artigo em Inglês | Scopus | ID: covidwho-2191639

RESUMO

Purpose: There is a well-documented trend among businesses for applying continuously improving, technologically-supported processes. This trend, in part, responds to evolving and challenging business environments and competitive pressures. It also increasingly mandates the need for businesses to invest in improving their digital capabilities and is driven by the expectation that such investments will better equip them for uncertain times. The COVID-19 pandemic presented disruptions to the supply chain, logistics, operations, market demand and labour supply, with industry reports providing evidence that businesses with digital capabilities were better able to respond to such disruptions promptly and appropriately. The study aims to investigate the effects of Industry 4.0 (I4.0) technologies on business operations and supply chain resilience. Design/methodology/approach: The authors surveyed 117 Australian manufacturing firms using an online survey and analysed the data by using the partial least square structural equation modelling method. Findings: The authors found I4.0 capabilities directly and positively impact supply chain resilience and that incremental innovation acts as a complementary mediator for the I4.0 technologies' relationship with supply chain resilience. I4.0 technology capability needs to first transfer to incremental innovation for operations resilience. The authors also found that incremental innovation and operations resilience are serial mediators in the relationship between I4.0 technologies and supply chain resilience. Originality/value: This research linked the three research areas of I4.0 implementations, innovation capabilities and resilience. To the best of the authors' knowledge, there has not been a previous study that investigated all three constructs together. Also, this study considered operations resilience and supply chain resilience as two distinct constructs and found I4.0 technologies had differential effects on them. The findings, thus, provide a novel contribution to the resilience, organizational capability and innovation literature. The investigations make clear to business practitioners how investments in technology and innovation capabilities translate into the resilience that is required in periods of disruption to business certainty. © 2022, Emerald Publishing Limited.

9.
7th China National Conference on Big Data and Social Computing, BDSC 2022 ; 1640 CCIS:23-39, 2022.
Artigo em Inglês | Scopus | ID: covidwho-2173950

RESUMO

University is one of the most likely environments for the cluster infection due to the long-time close contact in house and frequent communication. It is critical to understand the transmission risk of COVID-19 under various scenario, especially during public health emergency. Taking the Tsinghua university's anniversary as a representative case, a set of prevention and control strategies are established and investigated. In the case study, an alumni group coming from out of campus is investigated whose activities and routes are designed based on the previous anniversary schedule. The social closeness indicator is introduced into the Wells-Riley model to consider the factor of contact frequency. Based on the anniversary scenario, this study predicts the number of the infected people in each exposure indoor location (including classroom, dining hall, meeting room and so on) and evaluates the effects of different intervention measures on reducing infection risk using the modified Wells-Riley model, such as ventilation, social distancing and wearing mask. The results demonstrate that when applying the intervention measure individually, increasing ventilation rate is found to be the most effective, whereas the efficiency of increased ventilation on reducing infection cases decreases with the increase of the ventilation rate. To better prevent COVID-19 transmission, the combined intervention measures are necessary to be taken, which show the similar effectiveness on the reduction of infected cases under different initial infector proportion. The results provide the insights into the infection risk on university campus when dealing with public health emergency and can guide university to formulate effective operational strategies to control the spread of COVID-19. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

10.
Chinese Journal of New Drugs ; 31(21):2114-2119, 2022.
Artigo em Chinês | EMBASE | ID: covidwho-2111998

RESUMO

Objective: To evaluate the immunogenicity effect of CpG 7909 and Alum adjuvant to inactivated SARS-CoV-2 vaccine. Method(s): Mice were immunized with inactivated SARS-CoV-2 vaccines prepared with CpG 7909 and/or Alum adjuvant by intramuscular injection for 0 and 21 days. To evaluate the immunogenicity of inactivated SARS-CoV-2 vaccines with different adjuvants, serum samples were collected on Day 14, 28, 35 and 42 after immunization to detect the neutralizing antibody titers by microneutralization assay. Spleen samples were collected on Day 42 after immunization to detect the cellular immunity by flow cytometry and ELISPOT. Result(s): Compared with the inactivated SARS-CoV-2 vaccines adjuvanted with CpG 7909 or Alum only, the combination of CpG 7909 and Alum adjuvant significantly increased neutralizing antibody titers in mice and showed great cross-neutralization activity against the Delta variant. It also significantly induced the activation of specific IL-4, IFN-gamma and GCB cells. Conclusion(s): The combination of CpG 7909 and Alum adjuvant synergistically enhanced the humoral and cellular immune responses induced by inactivated SARS-CoV-2 vaccine and showed great cross-neutralization activity against the Delta variant. Copyright © 2022, Chinese Journal of New Drugs Co. Ltd. All right reserved.

11.
Innovation in Aging ; 5:910-910, 2021.
Artigo em Inglês | Web of Science | ID: covidwho-2011272
12.
Industrial and Commercial Training ; 2022.
Artigo em Inglês | Scopus | ID: covidwho-1973389

RESUMO

Purpose: The purpose of this paper is to contribute to the literature of blended learning by practically implementing best practices in employee training. Design/methodology/approach: In response to the Covid-19 pandemic, an organization had modified its training procedures over the course of three years to improve employee and organizational outcomes. Employee candidates who were onboarded into sales positions during the years 2019–2021 were given the opportunity to learn the content in an online format and subsequently evaluated prior to their in-person training and final evaluation to provide them with a self-paced blended learning experience. Both evaluation scores, along with the length it took to complete the trainings, were used to determine the trainings effectiveness and efficiency respectively. Findings: The findings for the study showed that the organization was successfully able to improve upon the efficiency of the training by reducing training length and the effectiveness by improving employee outcomes. Research limitations/implications: The study’s design was limited to the probation process, which resulted in issues drawing conclusions for employee outcomes that were relevant to their long-term organizational success. This emphasizes the importance of comprehensive investigations for future practical studies. Practical implications: The findings allow for the improvement of blended learning models within real-world organizational contexts that provide organizations with the opportunity to improve employee outcomes while reducing time costs. Originality/value: This study provides data from applied blended learning procedures that were validated using empirical findings, which contributes to the practicality of blended learning in workplace training. © 2022, Emerald Publishing Limited.

13.
Zhonghua Yi Xue Za Zhi ; 102: 1-6, 2022 Jun 13.
Artigo em Chinês | MEDLINE | ID: covidwho-1893003

RESUMO

Objective: The gold immunochromatographic assay for detection of SARS-CoV-2 antigen was evaluated by international multi-center clinical trial. Methods: A total of 1 855 clinical parallel samples with valid test results (for nucleic acid and antigen tests, respectively) were collected from nine countries, including Germany, the United Kingdom, Ukraine, France, India, Thailand, Malaysia, the United States of America and Brazil, with sampling period from January 3, 2021 to September 22, 2021. These samples were detected by SARS-CoV-2 antigen test kit (colloidal gold immunochromatography assay) and nucleic acid detection kit (real-time fluorescent quantitative reverse transcription polymerase chain reaction). Positive coincidence rates [(number of antigen-positive cases/nucleic acid-positive cases)×100%], negative coincidence rates [(number of antigen-negative cases/nucleic acid-negative cases)×100%], total coincidence rates [(number of cases with consistent results for both antigen and nucleic acid detection/number of total cases) ×100%], as well as Kappa values were calculated. The differences of the above indictors among different countries were evaluated by the coefficient of variation. The detection rates of the antigen test for samples with different cycle threshold values (Ct values) for the nucleic acid detection, different characteristics and different mutant strains were analyzed. Results: For all samples, the positive, negative, and total coincidence rate between the antigen test and nucleic acid assay was 90.8% (569/627), 99.7% (1 224/1 228) and 96.7% (1 793/1 855), respectively, and the consistency coefficient Kappa value was 0.924. Among these countries, the coefficient of variation for positive coincidence rates (except for Malaysia with a lot of samples with Ct value>30), negative coincidence rates (except for France without negative samples) and total coincidence rates (except for France) was 6%,<1%, and 6%, respectively. When Ct values were less than 25, the detection rates of antigen test were 83.3%-100% for each countries (the coefficient of variation was 6%); The total detection rate and the coefficient of variation was 93.4% (428/458) and 5%, respectively, for asymptomatic infected persons and cases within 7 days post onset of symptoms; the total detection rate for various SARS-CoV-2 mutant strains was 97.5% (119/122); and it showed negative results for samples from cases infected with other viruses, including influenza A virus subtype H1N1, influenza B virus, respiratory syncytial virus subgroups A and B, coxsackievirus 16, human metapneumovirus, parainfluenza virus types 1 and 4, Epstein-Barr virus and adenovirus. Conclusion: The SARS-CoV-2 antigen test kit showed excellent authenticity, and there were few differences for its indictors among nine countries, therefore it can meet the needs of large-scale early screening of SARS-CoV-2 infection.

14.
Journal of Electronic Imaging ; 31(2), 2022.
Artigo em Inglês | Scopus | ID: covidwho-1846312

RESUMO

Recent research on facial expression recognition (FER) in the wild shows challenges still remain. Different from laboratory-controlled expression in the past, images in the wild contain more uncertainties, such as different forms of face information occlusion, ambiguous facial images, noisy labels, and so on. Among them, real-world facial occlusion is the most general and crucial challenge for FER. In addition, because of the COVID-19 disease epidemic, people have to wear masks in public, which brings new challenges to FER tasks. Due to the recent success of the Transformer on numerous computer vision tasks, we propose a Collaborative Attention Transformer (CAT) network that first uses Cross-Shaped Window Transformer as the backbone for the FER task. Meanwhile, two attention modules are collaborated. Channel-Spatial Attention Module is designed to increase the attention of the network to global features. Moreover, Window Attention Gate is used to enhance the ability of the model to focus on local details. The proposed method is evaluated on two public in-The-wild facial expression datasets, RAF-DB and FERPlus, and the results demonstrate that our CAT performs superior to the state-of-The-Art methods. © 2022 SPIE and IST.

15.
Emerg Microbes Infect ; 11(1): 240-249, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: covidwho-1585242

RESUMO

ABSTRACTThe COVID-19 pandemic and measures against it provided a unique opportunity to understand the transmission of other infectious diseases and to evaluate the efficacy of COVID-19 prevention measures on them. Here we show a dengue epidemic in Yunnan, China, during the pandemic of COVID-19 was dramatically reduced compared to non-pandemic years and, importantly, spread was confined to only one city, Ruili. Three key features characterized this dengue outbreak: (i) the urban-to-suburban spread was efficiently blocked; (ii) the scale of epidemic in urban region was less affected; (iii) co-circulation of multiple strains was attenuated. These results suggested that countermeasures taken during COVID-19 pandemic are efficient to prevent dengue transmission between cities and from urban to suburban, as well to reduce the co-circulation of multiple serotypes or genotypes. Nevertheless, as revealed by the spatial analysis, once the dengue outbreak was established, its distribution was very stable and resistant to measures against COVID-19, implying the possibility to develop a precise prediction method.


Assuntos
Controle de Doenças Transmissíveis/métodos , Vírus da Dengue , Dengue/epidemiologia , Dengue/prevenção & controle , Dengue/transmissão , Animais , COVID-19/epidemiologia , COVID-19/prevenção & controle , China/epidemiologia , Chlorocebus aethiops , Surtos de Doenças/prevenção & controle , Genótipo , Humanos , Pandemias/prevenção & controle , Filogenia , RNA Viral , SARS-CoV-2 , Sorogrupo , Análise Espacial , Células Vero
16.
11th IEEE Annual International Conference on CYBER Technology in Automation, Control, and Intelligent Systems, CYBER 2021 ; : 91-95, 2021.
Artigo em Inglês | Scopus | ID: covidwho-1532667

RESUMO

Non-contact long-distance monitoring system could provide benefit for examination and monitoring of patients without infectious contamination and rapidly recognize infected patients in a high flow of people. Although on-body wearable sensing systems and infrared camera were widely developed for preventing COVID-19, however, there are still demands on the non-contact sensing systems for the public area of people with masks. In this paper, we present an Image-based non-contact breathing monitoring system for people wearing masks. By calculating the RGB values in nostrils region on the mask, the respiratory rate was successfully been obtained. The signal to noise ratio and influence of the size of the region, illumination condition and CMOS sensors were also studied. With appropriate measuring region, the monitoring system was able to record breath even the light illumination was 1 lumen. © 2021 IEEE.

17.
21st ACM Internet Measurement Conference, IMC 2021 ; : 54-61, 2021.
Artigo em Inglês | Scopus | ID: covidwho-1526551

RESUMO

Public cloud platforms are vital in supporting online applications for remote learning and telecommuting during the COVID-19 pandemic. The network performance between cloud regions and access networks directly impacts application performance and users' quality of experience (QoE). However, the location and network connectivity of vantage points often limits the visibility of edge-based measurement platforms (e.g., RIPE Atlas). We designed and implemented the CLoud-based Applications Speed Platform (CLASP) to measure performance to various networks from virtual machines in cloud regions with speed test servers that have been widely deployed on the Internet. In our five-month longitudinal measurements in Google Cloud Platform (GCP), we found that 30-70% of ISPs we measured showed severe throughput degradation from the peak throughput of the day. © 2021 ACM.

18.
Journal of General Internal Medicine ; 36(SUPPL 1):S416-S417, 2021.
Artigo em Inglês | Web of Science | ID: covidwho-1349140
20.
Separation and Purification Technology ; 274, 2021.
Artigo em Inglês | Scopus | ID: covidwho-1275710

RESUMO

Improvement on oxygen (O2) concentrator using pressure swing adsorption (PSA) technology according to variable product demands is of great significance, which, for instance, provides the key step for success in practical O2 therapy for COVID-19 patients who need to be delivered with a wide product flow rate range (1–15 standard liter per minute (SLPM)) of medical O2 (purity >82%). This work studied the individual effects of major PSA process parameters on O2 production performance at the product flow rate of 3.46–19.88 SLPM (0.64–3.68 SLPM per kilogram of adsorbent (SLPM/kg)), based on a self-designed two-bed PSA unit with a modified Skarstom cycle using Li-LSX zeolite adsorbents. The improvement strategies were accordingly proposed based upon influential mechanisms of each parameter: 1) at lower product flow rates (≤2.00 SLPM/kg), increasing the purge flow rate and decreasing the adsorption pressure to suppress excess O2 adsorption, and decreasing the feed flow rate to ensure low energy consumption;2) at higher product flow rates (≥2.00 SLPM/kg), decreasing the purge flow rate and increasing the adsorption pressure to eliminate N2 breakthrough and O2-rich product waste, and appropriately increasing the feed flow rate to enhance cost-effectiveness. An improved set of parameters rendered O2 purity (95.67–74.86%), recovery (11.28–49.05%), productivity (0.47–2.04 mmol/kg/s) increased by up to 3.52–20.08%, 0.36–20.47%, 6.82–19.61%, and energy consumption (4.07–0.95 kWh/kgO2) decreased by up to 10.56–18.10%, in comparison to two conventional sets, respectively. The results are beneficial for developing intellectualized and flexibly-controlled O2 concentrators for practical applications. © 2021 Elsevier B.V.

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