Analysis of pathogenic factors of retinopathy of prematurity in Heilongjiang Province (preprint)

Background and purpose Retinopathy of prematurity is a vascular development disorder in immature retinas of premature infants, which is the leading cause of blindness in children worldwide. Because the screening delay may lead to the occurrence of blindness in children, it is particularly important to conduct timely screening for children with high risk factors. Currently, the pathogenesis of ROP may be related to multiple factors such as gestational age and birth weight of premature infants. In this study, the prevalence and risk factors of ROP in Heilongjiang Province were determined through screening for premature infants in the region, aiming to proceed early prevention of the disease. Methods Retrospectively analyzed 714 premature infants admitted to the Ophthalmology Clinic of the Second Affiliated Hospital of Harbin Medical University from January 2016 to February 2022. 12 related factors was recorded including patients’ gender, gestational age, birth weight, oxygen duration, blood transfusions, anemia, neonatal infections, respiratory distress syndrome, maternal feeding way, childbirth way, pregnancy age and parity. The prevalence of ROP and the differences in related factors between ROP patientsand non-ROP patients were found. Results Among 714 premature infants, 188 had ROP of which the incidence is 26.3%，and 61 patients received treatment. There were statistically significance(P<0.05) in gestational age, birth weight, oxygen duration, blood transfusion, anemia, neonatal infection, respiratory distress syndrome and childbirth way between the 188 ROP patients and non-ROP patients in univariate regression analysis. Variables with statistical significance for single factor were selected and conducted by multivariate regression analysis, which showed that gestational age, birth weight, and oxygen duration had remarkable statistical significance(P<0.05) with the occurrence of ROP. Gestational age and birth weight were the protective factors of disease (OR=0.43 and OR=0.8), while oxygen duration was the risk factor of disease (OR=1.02), and the diagnostic value of the model was high (AUC=0.776). five of the 61 patients who received treatment for ROP accepted two treatments, with gestational age < 32 weeks, birth weight < 1500g, and oxygen inhalation time > 20 days. The Kendall grade relative analysis of 188 patients with ROP showed that disease severity was significantly correlated with gestational age, birth weight, oxygen duration, anemia, blood transfusion and respiratory distress syndrome(P<0.05), in which the gestational age, birth weight, anemia, blood transfusion and respiratory distress syndrome were negatively correlated with the severity of the disease, while oxygen duration was positively correlated with severity of the disease. 507 children were screened from 2016 to December 31th in 2019, 138 of which were ROP patients, 36 children were treated (7.1%). Due to the spread of the COVID-19, 207 children were screened after January 1th in 2020, 50 children were ROP patients, and 25 of whom got treatment (12%), 21were treated after 8 weeks of birth or more than 37 weeks of corrected gestational age. Four out of five children who received the second treatment happened after the epidemic, and three of them missed treatment due to the epidemic. Conclusions The gestational age, birth weight and oxygen duration are significantly correlated with the incidence and severity of the disease in premature infants screening of Heilongjiang Province. Premature infants screening and subsequent visit were affected due to the spread of the COVID-19 in the past two years, the proportion of children needed to be cured augmented apparently, therefore, it matters a lot for premature infants to be screened standardly and timely.

Pre-Service Teachers’ Perceptions of Emotions and Self-Regulatory Learning in Emergency Remote Learning

This study explored emotions and self-regulatory learning in postgraduate students, forced to transition to emergency remote teaching, at a Hong Kong university after the start of the academic semester. Self-regulation is a critical factor for successful online learning, and emotions are important antecedents of self-regulated learning. The study adopted a two-phase research design, with an initial online questionnaire (n = 52) followed by semi-structured interviews (n = 16) to gain a rich and holistic understanding of students’ experiences. Our findings indicate that: (1) locating a suitable location to attend online classes and sharing problems with classmates were the two most frequently self-regulatory learning strategies employed by students;(2) students experienced some enjoyment attending online classes but experienced increased pressure and time commitment to complete assigned work;(3) students found online learning to lack a sense of community, making it challenging to interact with classmates. The findings suggest teachers need to incorporate various synchronous and asynchronous collaborative activities, and they need to increase their own and students’ presence online to motivate and facilitate effective teaching and learning.

Design and Implementation of 5G eHealth Systems, Technologies, Use Cases and Future Challenges (preprint)

Fifth generation (5G) aims to connect massive devices with even higher reliability, lower latency and even faster transmission speed, which are vital for implementing the e-health systems. However, the current efforts on 5G e-health systems are still not enough to accomplish its full blueprint. In this article, we first discuss the related technologies from physical layer, upper layer and cross layer perspectives on designing the 5G e-health systems. We afterwards elaborate two use cases according to our implementations, i.e., 5G e-health systems for remote health and 5G e-health systems for Covid-19 pandemic containment. We finally envision the future research trends and challenges of 5G e-health systems.

Oil and BRIC Stock Markets before and after COVID-19: A Local Gaussian Correlation Approach

This paper investigates interdependence and contagion between oil and BRIC stock markets before and after COVID-19. We used a local Gaussian correlation approach to identify the asymmetric relationship and a bootstrap method to test contagion. The empirical results show that, except for China, the linkages between the crude oil markets and BRIC stock markets significantly increased in crashing markets during the COVID-19 pandemic. Contagion is identified from crude oil markets to the Indian stock market, and from West Texas Intermediate (WTI) futures to the Russian stock market.

Dynamic changes of D-Dimer and Neutrophil-Lymphocyte Count Ratio as prognostic biomarkers in COVID-19 (preprint)

Background: Since December 2019, the outbreak of COVID-19 caused a large number of hospital admissions in China. Many patients with COVID-19 have symptoms of acute respiratory distress syndrome, even are in danger of death. This is the first study to evaluate dynamic changes of D-Dimer and Neutrophil-Lymphocyte Count Ratio (NLR) as a prognostic utility in patients with COVID-19 for clinical use. Methods In a retrospective study, we collected data from 349 hospitalized patients who diagnosed as the infection of the COVID-19 in Wuhan Pulmonary Hospital. We used ROC curves and Cox regression analysis to explore critical value (optimal cut-off point associated with Youden index) and prognostic role of dynamic changes of D-Dimer and NLR. Results 349 participants were enrolled in this study and the mortality rate of the patients with laboratory diagnosed COVID-19 was 14.9%. The initial and peak value of D-Dimer and NLR in deceased patients were higher statistically compared with survivors (P<0.001). There was a more significant upward trend of D-Dimer and NLR during hospitalization in the deceased patients, initial D-Dimer and NLR were lower than the peak tests (MD) -25.23, 95% CI: -31.81- -18.64, P <0.001; (MD) -43.73, 95% CI:-59.28- -31.17, P <0.001. The test showed a stronger correlation between hospitalization days, PCT and peak D-Dimer than initial D-Dimer. The areas under the ROC curves of peak D-Dimer and peak NLR tests were higher than the initial tests (0.94(95%CI: 0.90-0.98) vs. 0.80 (95% CI: 0.73-0.87); 0.93 (95%CI:0.90-0.96) vs. 0.86 (95%CI:0.82-0.91). The critical value of initial D-Dimer, peak D-Dimer, initial NLR and peak NLR was 0.73 mg/L, 3.78 mg/L,7.13 and 14.31 respectively. 35 (10.03%) patients were intubated. In the intubated patients, initial and peak D-Dimer and NLR were much higher than non-intubated patients (P<0.001). The critical value of initial D-Dimer, peak D-Dimer, initial NLR and peak NLR in prognosticate of intubation was 0.73 mg/L, 12.75 mg/L,7.28 and 27.55. The multivariable Cox regression analysis showed that age (HR 1.04, 95% CI 1.00-1.07, P=0.01), the peak D-Dimer (HR 1.03, 95% CI 1.01-1.04, P<0.001) were prognostic factors for COVID-19 patients’death. Conclusions To dynamically observe the ratio of D-Dimer and NLR was more valuable during the prognosis of COVID-19. The rising trend in D-Dimer and NLR, or the test results higher than the critical values may indicate a risk of death for participants with COVID-19.

Olfactory and Gustatory Dysfunction as An Early Identifier of COVID-19 in Adults and Children: An International Multicenter Study (preprint)

Abstract Objective: Evaluate the prevalence and characteristics of olfactory or gustatory dysfunction in COVID-19 patients Study Design: Multicenter Case Series Setting: 5 tertiary care hospitals (3 in China, 1 in France, 1 in Germany) Subjects and Methods: 394 PCR confirmed COVID-19 positive patients were screened, and those with olfactory or gustatory dysfunction were included. Data including demographics, COVID-19 severity, patient outcome, and the incidence and degree of olfactory and/or gustatory dysfunction were collected and analyzed. The Questionnaire of Olfactory Disorders (QOD) and Visual Analogue Scale (VAS) were used to quantify olfactory and gustatory dysfunction respectively. All subjects at one hospital (Shanghai) without subjective olfactory complaints underwent objective testing. Results: Of 394 screened subjects, 161 (41%) reported olfactory and/or gustatory dysfunction and were included. Incidence of olfactory and/or gustatory disorders in Chinese (n=239), German (n=39) and French (n=116) cohorts were 32%, 69%, and 49% 138 respectively. The median age of included subjects was 39 years old, 92/161 (57%) were male, and 10/161 (6%) were children. Of included subjects, 10% had only olfactory or gustatory symptoms, and 19% had olfactory and/or gustatory complaints prior to any other COVID-19 symptom. Of subjects with objective olfactory testing, 10/90 demonstrated abnormal chemosensory function despite reporting normal subjective olfaction. 43% (44/102) of subjects with follow-up showed symptomatic improvement in olfaction or gustation. Conclusions: Olfactory and/or gustatory disorders may represent early or isolated symptoms of SARS-CoV-2 infection. They may serve as a useful additional screening criterion, particularly for the identification of patients in the early stages of infection.

Clinical features of middle-aged patients died of 2019 Novel Coronavirus–Infected Pneumonia (preprint)

Background Since December, 2019, the emerge of a Novel Coronavirus Disease 2019 (COVID-19) have caused global concern, the majority viewpoints are that the deaths are related to advanced ages, however, the emergence of younger deaths needs immediate attention.Methods Clinical characteristics, laboratory results, chest CT scans and treatment measures were retrospectively reviewed for six deceased patients under 60 years old with confirmed COVID-19 who were admitted to Wuhan Pulmonary Hospital in Wuhan, Hubei Province, China, from 6th January to 4th March, 2020.Results The age range of the patients was 50.17 ± 3.25 years (45–55 years), none of them had underlying diseases. All of patients presented with the symptoms of fever, respiratory system and digestive system. The level of albumin and lymphocyte counts decreased early in the stages of the disease, and then gradually increased. The neutrophil to lymphocyte ratio (NLR) increased (higher than normal range) in early stage and gradually decreased when the disease progressed. All the six patients showed ground-glass opacity (GGO) and bilateral patchy shadowing in early stage under the computed tomography (CT). All the patients died of severe pneumonia and multiple organ failure.Conclusions The decreased level of serum albumin occurred in the early stages of the disease, and delays in the first admission to hospital probably aggravate the disease development. The increase of the NLR in early stage of disease may be a risk of death for COVID-19. These findings may provide useful information for optimizing supportive care for COVID-19 pneumonia.

Research on pneumonia exacerbation in patients infected with SARS-CoV-2 in Wuhan, China (preprint)

Background SARS-CoV-2 pneumonia occasionally exacerbates to critical condition that is hard to manage. We aim to describe exacerbations of SARS-CoV-2 pneumonia among inpatients.Methods We included confirmed SARS-CoV-2 patients with pneumonia exacerbation admitted to Wuhan Pulmonary Hospital, Hubei Province, China between January 6 and February 17, 2020 and discharged or died before February 25. Their demographic characteristics, clinical symptoms, laboratory tests, CT manifestations, complications and clinical outcomes were collected.Results A total of 158 patients were collected, among them 107 patients were stable and discharged after recovery, 24 patients were already critically severe at hospital admission. 14 patients were excluded for insufficient clinical data. Eventually, 13 confirmed cases were included. The mean age was 65 (± 9.81) years. Ten of the 13 (76.9%) patients were female. Nine (69.2%) had underlying comorbidities. Fever and cough were the most common symptoms (12/13, 92.3%). 10/13(76.9%) patients had their exacerbation in the second week of disease course. All patients had both negative and positive nucleic acid test (NAT) results during the course. Increased range of ground-glass opacity (GGO) on CT imaging are consistent to disease exacerbation. ARDS, MODS, respiratory failure were found in 5/13(38.5%), 3/13(23.1%), 6/13(46.2%) patients respectively. Five (38.5%) patients did not survive.Conclusions SARS-CoV-2 pneumonia exacerbations often occurs in the second week of disease course. Negative NAT result could not exclude exacerbation. CT manifestation is consistent with disease progression. Early admissions have positive effects on reducing complications and mortality.