ABSTRACT
One–step preparation of electrospun bimodal fibrous membrane based on single nozzle is the key to the efficient fabrication of high–performance air filter. However, the preparation mechanism of electrospun bimodal fibers at low conductivity solution system is not clear, and there is a lack of evaluation methods for the quality of bimodal nanofibers, which limits the applicability of single nozzle electrospinning and the preparation efficiency of electrospun bimodal fibers. Here, three electrospinning processes at low conductivity solution systems of polyamide–6 (PA6), PA6 blended PVP (PA6/PVP), and PA6 blended polyethylene oxide (PA6/PEO) were studied according to the rheological properties and the fluid electrics (i.e., zeta potential), and the quality of the prepared bimodal fibrous membrane was creatively evaluated by R value. Inhomogeneous phase separations of the electrospinning jet along the direction parallel (x–axis) or perpendicular (y–axis) to the electric field were responsible for the formation of bimodal fibers. In addition, for the same solution system, the R value had a positive correlation with the air filtration performance. This work will greatly enhance the applicability of one–step single nozzle electrospinning for the preparation of bimodal nanofibers, improve the preparation efficiency, and promote the development of high–performance air filter. © 2022 Elsevier Ltd
ABSTRACT
The global health situation caused by the SARS-CoV-2 virus has forced some universities to combine face-to-face and online teaching. The objective of this investigation is to analyze how university students themsel-ves assessed bimodal teaching. 445 students from the four Nursing Degree programs completed a survey that gathered data on sociodemographic variables and included a Likert-type scale on bimodal teaching. Values of central tendency and dispersion were calculated, as were correlations between the different variables. 17 of the 24 items of the scale are distributed into 3 groups. The first compares face-to-face and online teaching (M = 3.70, SD = .94), the second asks about the adaptation of the teaching center to bimodality (M = 3.58, SD = 2.02) and the third investigates the role of teachers (M = 3.58, SD = .86). More than 76% of students express a preference for face-to-face teaching, almost 80% positively assess their centers' organization, and 67% positively assess the role of teachers. Knowledge of university students' opinions about bimodal teaching as a potential educational model will help reduce this model's weaknesses.
ABSTRACT
BACKGROUND: Both SARS-CoV-2 mRNA-based vaccines [BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna)] have shown high efficacy, with very modest side effects in limiting transmission of SARS-CoV-2 and in preventing the severe COVID-19 disease, characterized by a worrying high occupation of intensive care units (ICU), high frequency of intubation and ultimately high mortality rate. At the INT, in Naples, only the BNT162b2/Pfizer vaccine has been administered to cancer patients and healthcare professionals aged 16 and over. In the present study, the antibody response levels and their decline were monitored in an interval of 6-9 months after vaccine administration in the two different cohorts of workers of the INT - IRCCS "Fondazione Pascale" Cancer Center (Naples, Italy): the group of individuals previously infected with SARS-CoV-2 and vaccinated with a single dose; and that of individuals negative for previous exposure to SARS-CoV-2 vaccinated with two doses 21 days apart. METHODS: Specific anti-RBD (receptor-binding domain) titers against trimeric spike glycoprotein (S) of SARS-CoV-2 by Roche Elecsys Anti-SARS-CoV-2 S ECLIA immunoassay were determined in serum samples of 27 healthcare workers with a previously documented history of SARS-CoV-2 infection and 123 healthcare workers without, during antibody titers' monitoring. Moreover, geometric mean titers (GMT) and relative fold changes (FC) were calculated. RESULTS: Bimodal titer decline was observed in both previously infected and uninfected SARS-CoV-2 subjects. A first rapid decline was followed by a progressive slow decline in the 6/9 month-period before the further vaccine boost. The trend was explained by 2 different mathematical models, exponential and power function, the latter revealing as predictive of antibody titer decline either in infected or in not previously infected ones. The value of the prolonged lower vaccine titer was about 1 log below in the 6/9-month interval after the single dose for previously infected individuals with SARS-CoV-2 and the two doses for those not previously infected. The titer change, after the boost dose administration, on the other hand, was ≥ 1.5 FC higher than the titers at the 6/9-month time-points in both cohorts. A similar quantitative immune titer was observed in both cohorts 8 days after the last boost dose. The subsequent immunoresponse trend remains to be verified. DISCUSSION: The results show that a very rapid first decline, from the highest antibody peak, was followed by a very slow decline which ensured immune protection lasting more than 6 months. The apparent absence of adverse effects of the rapid decline on the vaccine's immune protective role has been related to a large majority of low avidity antibodies induced by current vaccines. High avidity antibodies with prolonged anti-transmission efficacy show a longer half-life and are lost over a longer interval period. The cellular immunity, capable of preventing severe clinical diseases, lasts much longer. The unbalanced dual activity (cellular vs humoral) while effective in limiting ICU pressure and overall mortality, does not protect against transmission of SARS-CoV-2, resulting in high circulation of the virus among unvaccinated subjects, including the younger population, and the continuous production of variants characterized by changes in transmissibility and pathogenicity. The high mutation rate, peculiar to the RNA virus, can however lead to a dual opposite results: selection of defective and less efficient viruses up to extinction; risk of more efficiently transmitted variants as the current omicron pandemic. CONCLUSIONS: In conclusion the current bimodal antibody-titer decline, following BNT162b2 mRNA anti-SARS-CoV-2 vaccination, needs a further extended analysis to verify the protective borderline levels of immunity and the optimal administration schedule of vaccine boosters. Our current results can contribute to such goal, besides a direct comparison of other FDA-approved and candidate vaccines.
ABSTRACT
The bimodal education model adopted by some spanish universities during the post-confinement period has been based on making presentiality, and nonpresentiality, teaching compatible, in order to adapt satisfactorily to the new reality of university classrooms. The leap to virtuality last year allowed us to enrich the traditional teaching model with respect to the future, and the course of the current year leads us to the combination of both types of education, presentiality, and virtual, whose main contribution is to provide continuity to a school year, and also, to achieve flexibility in pedagogical strategies. In addition, the rethinking of the teaching learning process has involved an important restructuring of spaces and processes that ensure not only the health of all members of the university community, but also quality teaching to promote the permanent intellectual and personal development of students. in the time. The success of the social transformation in which we are immersed depends largely on education;therefore, the educational community must adjust itself adequately to these new circumstances. In the future, it will be important to inquire with perspective about the impact of all the changes caused by COVID in the teaching and learning process of students and teachers. A transcendental aspect will be to know the progress of students in the post-pandemic era and adopt the pedagogical actions that are necessary to adapt to this new scenario.
ABSTRACT
COVID-19 is a disease caused by SARS-CoV-2 that can arouse a respiratory tract infection. Therefore, a rapid identification of clearly visualized infections is urgently needed, which can assist early diagnosis and save the lives of suspected COVID-19 patients.Recent technological progress has made it possible to fuse deep learning classification and medical images that can accelerate and improve the accuracy of results when leveraged. This could particularly be important for disease where faster result and increased accuracy can help early detection of COVID-19 cases vis-à-vis the traditional RT-PCR tests. DNN classifier is designed such that, it automatically detects virus present in lungs using chest image is termed as Bimodal. This research article proposes an automatic frame work for identifying COVID -19 as early using chest X-ray images and CT Scan Images. For this experiment, 3 types of data set are used, 1) COVID X-ray chest 2) CT-scan SARS-COV-2, 3), X-Ray images in the chest (Pneumonia). This deep learning model can detect positive COVID-19 cases more quickly than RT-PCR tests for the detection of COVID-19 cases. The proposed model provides a relationship between COVID-19 patients and pneumonia patients. Color visualization approach on the basis of Grad-CAM is used to clearly interpret image radiology detection. The proposed deep learning model has achieved a total accuracy of 92.33%, with precision and recall of 0.94% and 0.93%. © 2021 IEEE.
ABSTRACT
Recently, contactless bimodal palmprint recognition technology has attracted increased attention due to the COVID-19 pandemic. Many dual-camera-based sensors have been proposed to capture palm vein and palmprint images synchronously. However, translations between captured palmprint and palm vein images differ depending on the distance between the hand and the sensors. To address this issue, we designed a low-cost method to align the bimodal palm regions for current dual-camera systems. In this study, we first implemented a contactless palm image acquisition device with a dual-camera module and a single-point time of flight (TOF) ranging sensor. Using this device, we collected a dataset named DCPD under different distances and light source intensities from 271 different palms. Then, a bimodal palm image alignment method is proposed based on the imaging and ranging models. After the system model is calibrated, the translation between the visible light and infrared light palm regions can be estimated quickly based on the palm distance. Finally, we designed a convolutional neural network (CNN) to effectively extract the fine- and coarse-grained palm features. Compared to widely used existing methods, the proposed networks achieved the lowest equal error rate (EER) on the Tongji, IITD, and DCPD datasets, and the average time cost of the system to perform one-time identification is approximately 0.15 s. The experimental results indicate that the proposed methods achieved high efficiency and comparable accuracy. In addition, the system's EER and rank-1 on the DCPD dataset were 0.304%and 98.66%, respectively. IEEE
ABSTRACT
Following the perpetual political-military crises, most of the rural areas of the Central African Republic (CAR) are occupied by armed groups. This leads to human insecurity in these areas. Children, adolescents, and youth are out of school. Primary and secondary school teachers are unable to travel to unsafe areas. Due to the problem of human insecurity in rural areas and especially poverty in several rural areas of CAR, parents are unable to finance the education of their children who have taken the baccalaureate exams to travel to the capital Bangui to study at Bangui University alone. In this article, we propose a platform for the continuity of educational activities in the Central African Republic. Our initially proposed platform solution allows the creation of a distance primary and secondary school in bimodal mode in the rural areas of the CAR. In a second step, it allows the creation of a complete distance university training coupled with traditional education for young people from all rural areas of the Central African Republic. This platform has been tested at the Higher Institute of Technology (Department of Computer Science and Telecommunications) and the Faculty of Science of the University of Bangui and has enabled the partial resumption of pedagogical activities in these institutions. It has been applied in the field of STEM (science, technology, engineering and mathematics) and can be extended to other disciplines. Access to resources is efficient thanks to the coupling of the WireGuard VPN server and the Apache Guacamole server which is a gateway using standard protocols via a browser. It also uses VXLAN technology which moves the WireGuard VPN server subnet from OSI Layer 3 to Layer 2 and allows the organization of practical work that requires being in the same local subnet. Access to this platform provides learners in the Central African Republic with a complete and secure distance learning environment for courses, assignments and tutorials. © 2021 ACM.
ABSTRACT
BACKGROUND: C-reactive protein (CRP) is a non-specific acute phase reactant elevated in infection or inflammation. Higher levels indicate more severe infection and have been used as an indicator of COVID-19 disease severity. However, the evidence for CRP as a prognostic marker is yet to be determined. The aim of this study is to examine the CRP response in patients hospitalized with COVID-19 and to determine the utility of CRP on admission for predicting inpatient mortality. METHODS: Data were collected between 27 February and 10 June 2020, incorporating two cohorts: the COPE (COVID-19 in Older People) study of 1564 adult patients with a diagnosis of COVID-19 admitted to 11 hospital sites (test cohort) and a later validation cohort of 271 patients. Admission CRP was investigated, and finite mixture models were fit to assess the likely underlying distribution. Further, different prognostic thresholds of CRP were analysed in a time-to-mortality Cox regression to determine a cut-off. Bootstrapping was used to compare model performance [Harrell's C statistic and Akaike information criterion (AIC)]. RESULTS: The test and validation cohort distribution of CRP was not affected by age, and mixture models indicated a bimodal distribution. A threshold cut-off of CRP ≥40 mg/L performed well to predict mortality (and performed similarly to treating CRP as a linear variable). CONCLUSIONS: The distributional characteristics of CRP indicated an optimal cut-off of ≥40 mg/L was associated with mortality. This threshold may assist clinicians in using CRP as an early trigger for enhanced observation, treatment decisions and advanced care planning.