Dupilumab Therapy of Prurigo Nodularis: A Single-Center, Real-Life Observational Study

Prurigo nodularis (PN) is a chronic inflammatory skin disease characterized by severe itching accompanied by multiple nodules throughout the body. There is currently no efective drug-targeted treatment for PN. Dupilumab is a fully human monoclonal antibody which can suppress the Th2 inflammatory reaction. We aimed to assess the efficacy and safety of dupilumab in PN. There were 29 PN patients who received dupilumab treatment for four months. Serum total immunoglobulin E (Ig E), eosinophil counts, dermatology life quality index (DLQI), and numeric rating scale (NRS) were assessed on patients before and after treatment. We count the vaccination of novel coronavirus pneumonia (COVID-19) in patients and the impact on PN and treatment measures after vaccination. Plotting was performed using GraphPad Prism8, and the statistical analysis was performed using PASW Statistics18. The eosinophil counts in patients higher decreased to normal, and the Ig E levels gradually decreased and tended to normal levels after receiving dupilumab injection. The average DLQI score at the baseline was 23.93 +/- 0.66 and decreased to 11.66 +/- 0.55 (P < 0.01) and 1.83 +/- 0.22 (P < 0.01) at 1-month and 6-monthfollow-up of treatment, respectively. The average NRS score at the baseline was 9.79 +/- 0.08 and decreased to 3.52 +/- 0.23 (P < 0.01) and 0.31 +/- 0.15 (P < 0.01) at the 1-month and 6monthfollow-up of treatment, respectively. Our study shows that dupilumab has achieved good efficacy in PN with few adverse reactions and high safety. We can recommend that patients follow the advice of specialists to be vaccinated and under the condition of stable disease, separated from dupilumab treatment for one week.

Prediction and Analysis of COVID-19 Epidemic Based on Improved GEP Algorithm to Optimize SEIR Mode

In 2019, COVID-19 (CoronaVirus Disease 2019) broke out all over the world. COVID-19 is an infectious disease, which has a huge impact on the global economy. It is very difficult to prevent and control the epidemic situation of this infectious disease. At present, many SEIR(Susceptible Exposed Infected Recovered)models are used to predict the number of infectious diseases, which has the shortcomings of low prediction accuracy and inaccurate inflection point prediction. Therefore, this paper proposes that the prediction and analysis of COVID-19 based on improved GEP algorithm and optimized SEIR model can improve the prediction accuracy and inflection point prediction accuracy, and provide a theoretical basis for epidemic prevention of large-scale infectious diseases in the future. The algorithm. First, establish SEIR (Susceptible Exposed Infected Recovered) model to analyze the epidemic trend, and then use improved GEP (Gene Expression Programming) algorithm to analyze the infection coefficient of SEIR model beta And coefficient of restitution y, perform parameter estimation to optimize the initial value I and recovery coefficient of the infected population y and so on to improve the accuracy of model prediction. The experimental data take the number of COVID-19 infected people in the United States, China, the United Kingdom and Italy as examples. The results show that the SEIR model optimized based on the improved GEP algorithm conforms to the inflection point of the actual data, and the average error value is 1.32%. The algorithm provides a theoretical basis for the future epidemic prevention. © 2022 IEEE.

Remote telemedicine strategy based on multi-risks intervention by intelligent wearable health devices in elderly comorbidities patients with coronary heart disease

Background: Telemedicine based on wearable intelligent health devices becomes increasingly promissing for the elderly due to the accelerated aging population. Especially during COVID-19 pandemic, more elderly coronary heart disease patients with chronic comorbidities are in less secondary prevention management at home. Objective(s): To explore the prevention effect on main cardiovascular risk factors and repeated hospitalization in elderly comorbidities patients by telemedicine intervention based on multi-parameter wearable monitoring devices. Method(s): Total of 337 patients with comorbidities of coronary heart disease, hypertension and diabetes, with age more than 65 years old were recruited in the study from October 2019 to January 2021. They were randomly divided into control group and telemedcine intervention group. The latter used remote multi-parameter wearable devices to measure blood pressure, glycemic and electrocardiograph at home every day. A real-time monitoring platform would alarm any abnormal data to the doctors. Both doctors and patients can read the measurement results on a real-time mobile phone APP and interact with each other remotely twice a week routinely. A medical team remotely indicated the medications, while offering guidance on lifestyle. In contrast, the control group adopted traditional outpatient medical strategy to manage diseases. Result(s): A total of 306 patients were enrolled in the follow-up experiment finally: 153 in the intervention group and 153 in the control group. Patient characteristics at baseline were balanced between two groups. After 12 months, compared with the control group, the intervention group saw the following metrics significantly reduced: Systolic blood pressure (SBP) (131.66+/-9.43 vs 137.20+/-12.02 mmHg, P=0.000), total cholesterol (TC) (3.65+/-0.79 vs 4.08+/-0.82 mmol/L, P=0.001), low density lipoprotein cholesterol (LDL-C) (2.06+/-0.53 vs 2.38+/-0.61 mmol/L, P=0.002), and fasting blood glucose (FBG) (6.26+/-0.75 vs 6.81+/-0.97 mmol/L, P=0.000), while the following metrics went up significantly: Blood pressure control rate (77.3% vs 59.1%, P=0.039), blood lipid control rate(39.4% vs 21.2%, P=0.037), glycemic control rate (71.2% vs 51.5%, P=0.031), and medication adherence score (7.10+/-0.77 vs 6.80+/-0.73, P=0.020). Linear regression model analysis indicates that when interaction frequency >=1.53, 2.47 and 1.15 times/week, the SBP, LDL-C and FBG levels would be controlled, respectively. Cox survival analysis finds that the hospitalization rate of intervention group is significantly lower than that of the control group (24.18% vs 35.29%, P=0.031). Conclusion(s): The telemedicine interactive intervention based on multiparameter wearable devices provides effectively improvement of cardiovascular risk controlling, medication adherence, while reducing the hospitalization rate of patients. A frequency of doctor-patient interactions more than 2 times/week is beneficial for disease management the elderly at home. (Figure Presented) .

GeauxTrace: A Scalable Privacy-Protecting Contact Tracing App Design Using Blockchain

Contact tracing is the approach to identifying physical contact between human beings using a variety of data such as personal details and locations to discover the potential infection of diseases. Since the outbreak of the COVID-19 pandemic, contact tracing has been used extensively to quarantine the people at risk to stop the spread. Moreover, the data collected during contact tracing are typical spatiotemporal data, which can be used to study the disease and discover the spread pattern. However, both traditional labor-intensive and modern digital-based approaches have limitations in terms of cost and privacy concerns. In this paper, we proposed GeauxTrace, a Blockchain-based privacy-protecting contact tracing platform, which separates private data from proof of contact. Sensitive data collected by the front-end app via Bluetooth-based methods are stored locally, and only the proofs of contacts are uploaded onto the immutable private blockchain, which forms a global contact graph at the backend. Our approach not only enables multi-hop risky users to be notified but also reveals the infection patterns via the global graph, which could help study diseases and assist the policymaker. Our implementation shows the feasibility of the proposed platform in real-world scenarios and achieves the performance of 20-30 user requests per second. © 2022 IEEE.

Assessment of residual chlorine in soil microbial community using metagenomics

Chlorine-containing disinfectants have been widely used around the world for the prevention and control of the COVID-19 pandemic. However, at present, little is known about the impact of residual chlorine on the soil micro-ecological environment. Herein, we treated an experimental soil-plant-microbiome microcosm system by continuous irrigation with a low concentration of chlorine-containing water, and then analyzed the influence on the soil microbial community using metagenomics. After 14-d continuous chlorine treatment, there were no significant lasting effect on soil microbial community diversity and composition either in the rhizosphere or in bulk soil. Although metabolic functions of the rhizosphere microbial community were affected slightly by continuous chlorine treatment, it recovered to the original status. The abundance of several resistance genes changed by 7 d and recovered by 14 d. According to our results, the chlorine residue resulting from daily disinfection may present a slight long-term effect on plant growth (shoot length and fresh weight) and soil micro-ecology. In general, our study assisted with environmental risk assessments relating to the application ofchlorine-containing disinfectants and minimization of risks to the environment during disease control, such as COVID-19. © 2022, Higher Education Press.

Remote telemedicine strategy based on multi-risks intervention by intelligent wearable health devices in elderly comorbidities patients with coronary heart disease

Background: Telemedicine based on wearable intelligent health devices becomes increasingly promissing for the elderly due to the accelerated aging population. Especially during COVID-19 pandemic, more elderly coronary heart disease patients with chronic comorbidities are in less secondary prevention management at home. Objective: To explore the prevention effect on main cardiovascular risk factors and repeated hospitalization in elderly comorbidities patients by telemedicine intervention based on multi-parameter wearable monitoring devices. Methods: Total of 337 patients with comorbidities of coronary heart disease, hypertension and diabetes, with age more than 65 years old were recruited in the study from October 2019 to January 2021. They were randomly divided into control group and telemedcine intervention group. The latter used remote multi-parameter wearable devices to measure blood pressure, glycemic and electrocardiograph at home every day. A real-time monitoring platform would alarm any abnormal data to the doctors. Both doctors and patients can read the measurement results on a real-time mobile phone APP and interact with each other remotely twice a week routinely. A medical team remotely indicated the medications, while offering guidance on lifestyle. In contrast, the control group adopted traditional outpatient medical strategy to manage diseases. Results: A total of 306 patients were enrolled in the follow-up experiment finally: 153 in the intervention group and 153 in the control group. Patient characteristics at baseline were balanced between two groups. After 12 months, compared with the control group, the intervention group saw the following metrics significantly reduced: systolic blood pressure (SBP) (131.66±9.43 vs 137.20±12.02 mmHg, P=0.000), total cholesterol (TC) (3.65±0.79 vs 4.08±0.82 mmol/L, P=0.001), low density lipoprotein cholesterol (LDL-C) (2.06±0.53 vs 2.38±0.61 mmol/L, P=0.002), and fasting blood glucose (FBG) (6.26±0.75 vs 6.81±0.97 mmol/L, P=0.000), while the following metrics went up significantly: blood pressure control rate (77.3% vs 59.1%, P=0.039), blood lipid control rate(39.4% vs 21.2%, P=0.037), glycemic control rate (71.2% vs 51.5%, P=0.031), and medication adherence score (7.10±0.77 vs 6.80±0.73, P=0.020). Linear regression model analysis indicates that when interaction frequency ≥1.53, 2.47 and 1.15 times/week, the SBP, LDL-C and FBG levels would be controlled, respectively. Cox survival analysis finds that the hospitalization rate of intervention group is significantly lower than that of the control group (24.18% vs 35.29%, P=0.031). Conclusion: The telemedicine interactive intervention based on multi-parameter wearable devices provides effectively improvement of cardiovascular risk controlling, medication adherence, while reducing the hospitalization rate of patients. A frequency of doctor-patient interactions more than 2 times/week is beneficial for disease management the elderly at home. Funding Acknowledgement: Type of funding sources: Foundation. Main funding source(s): Key scientific research project of Health CommissionFigure 1. ResultsFigure 2. Flowchart and intervention strategy

PHASE 1b STUDY TO EVALUATE SAFETY, TOLERABILITY, PHARMACOKINETICS, AND ANTI-HEPATITIS B VIRUS (HBV) ACTIVITY OF NCO-48 FUMARATE (NCO48F), A NOVEL LIVER-TARGETED PRODRUG (LTP) OF TENOFOVIR (TFV), IN TREATMENT-NAIVE ADULTS WITH CHRONIC HBV INFECTION

Background: TFV is a nucleotide analogue whose active form, TFV diphosphate (TDP), inhibits reverse transcription of hepatitis B virus (HBV) and is the active metabolite of HBV treatment TFV alafenamide (TAF). NCO-48F is a novel TFV prodrug designed to increase the liver concentration and maximize efficacy and/or potency while reducing drug exposure outside of the liver. NCO-48F is expected to minimize kidney and bone toxicity by reducing systemic exposure of TFV. Method(s): Safety, tolerability, pharmacokinetics (PK), and anti-HBV activity of multiple daily oral doses of 4 and 20 mg of NCO-48F, compared with 25 mg TAF, were evaluated in a randomized, open-label, active-controlled, parallel-assignment study in adult subjects with treatment-naive HBV infection (3 groups of 8 subjects each). Each subject was administered NCO-48F or TAF daily for 28d and followed for 28d after the last dose. Result(s): Preliminary data from 12 subjects (4 subjects/group) were available for analysis. NCO-48F at 4 mg and 20 mg and TAF were safe and well tolerated. No subjects had a serious adverse event (AE) or were discontinued due to an AE. There were no clinically significant or dose-dependent changes in hematology, clinical chemistry, urinalysis, electrocardiograms, or vital signs. One treatment-emergent AE was reported by 1 NCO-48F 4 mg subject (COVID-19 infection) which was not considered drug-related. NCO-48F was orally absorbed with Cmax observed within 30 minutes. NCO-48F was metabolized to TFV and rapidly cleared. Minimal urinary excretion of intact NCO-48F was detected, consistent with conversion to TFV. TFV Cmax was observed within one hour of NCO-48F administration, a faster uptake than observed after TAF administration. TFV elimination kinetics appeared similar after administration of either NCO-48F or TAF. Plasma concentrations of NCO-48F and TFV increased approximately dose proportionately. Over 28d of treatment, declines in serum HBV DNA levels (log10 IU/mL) were observed among all dose groups, and mean changes in HBV DNA at day 28 were -2.12 and -3.29 for NCO48F 4 mg and 20 mg, and -3.27 for TAF. Three subjects treated with NCO48F 20 mg had levels below limit of quantitation during treatment, and recovery of HBV DNA levels was slower during the follow- up period compared to subjects treated with TAF. Conclusion(s): NCO-48F is a promising agent for the treatment of HBV, demonstrating excellent safety and PK properties, and declines in HBV DNA comparable to TAF.

Causal Associations Between Body Fat Accumulation and Covid-19 Severity: A Mendelian Randomization Study

Background: Previous studies reported associations between obesity measured by body mass index (BMI) and coronavirus disease 2019 (COVID-19). However, BMI is calculated only with height and weight and cannot distinguish between body fat mass and fat-free mass. Thus, it is not clear if one or both of these measures are mediating the relationship between obesity and COVID-19. Aims: To elucidate the independent causal relationships of body fat mass and fat-free mass with COVID-19 severity using Mendelian randomization (MR). Results: We identified single nucleotide polymorphisms associated with body fat mass and fat-free mass in 454,137 and 454,850 individuals of European ancestry from the UK Biobank, respectively. We then performed two-sample MR to ascertain their effects on severe COVID-19 (cases: 4,792;controls: 1,054,664) from the COVID-19 Host Genetics Initiative. We found that an increase in body fat mass by one standard deviation was associated with severe COVID-19 (odds ratio (OR)body fat mass = 1.61, 95% confidence interval [CI]: 1.28-2. 04, P = 5.51×10-5;ORbody fat-free mass = 1.31, 95% CI: 0.99-1.74, P = 5.77×10-2). Considering that body fat mass and fat-free mass were genetically correlated with each other (r = 0.64), we further evaluated the independent causal effects of body fat mass and fat-free mass using multivariable MR and revealed that only body fat mass was independently associated with severe COVID-19 (ORbody fat mass = 2.91, 95%CI: 1.71-4.96, P = 8.85×10-5 and ORbody fat-free mass = 1. 02, 95%CI: 0.61-1.67, P = 0.945). Conclusions: This study demonstrates the causal effects of body fat accumulation on COVID-19 severity and indicates that the biological pathways influencing the relationship between COVID-19 and obesity are likely mediated through body fat mass.Presentation: No date and time listed

ADDICTION MEDICINE IS MEDICINE: A REQUIRED TWO-WEEK CLINICAL ROTATION FOCUSED ON SUBSTANCE USE FOR INTERNAL MEDICINE RESIDENTS

SETTING AND PARTICIPANTS: Montefiore Health System is the largest health care provider in Bronx, New York, a community that is disproportionately impacted by substance use disorders (SUDs). To better prepare resident physicians to care for patients with SUDs, we developed a novel addiction medicine rotation required for internal medicine residents. DESCRIPTION: The 2-week rotation includes inpatient and outpatient clinical experiences. During the inpatient week, residents rotate on the Addiction Consult Service, staffed by an addiction medicine attending, a fellow, and a peer navigator. Residents attend a weekly interdisciplinary meeting with the Psychiatry Consult Service to discuss cases. During the outpatient week, residents rotate through an opioid treatment program, an intensive outpatient substance use treatment program, and an addiction medicine “Bridge” clinic, which links patients with SUDs to primary care post- hospitalization. Residents also complete a self-study curriculum that includes addiction-focused readings and podcasts as well as the 8-hour online buprenorphine waiver training. All residents participate in Addiction Medicine Rounds, a weekly case conference and journal club led by addiction medicine faculty and trainees. EVALUATION: Between July and November 2021, 22 internal medicine residents participated in the rotation and 12 (55%) completed formal evaluations. All residents rated the overall rotation to be valuable for their education, with 33% in strong agreement based on a 4-point scale from strongly disagree to strongly agree. All residents also agreed (with 42% strongly agreed) that the rotation increased their knowledge and skills in diagnosing SUDs, and managing medication treatment for SUDs. One resident summarized: “This rotation is one of the best rotations I have experienced during my time as a resident. After completing this rotation, I felt very confident in my ability to diagnose, navigate, and manage the complexities of addiction related illness.” DISCUSSION / REFLECTION / LESSONS LEARNED: The Addiction Medicine Rotation was well-received in its first months of implementation. The experience on the Addiction Consult Service stood out as high-yield training, building on residents' familiarity with hospital-based care and leveraging multidisciplinary partnerships with psychiatry, pharmacy, and nursing departments. Providing rigorous inpatient training in addiction medicine is a unique feature of this rotation, as addiction consult services are not the mainstay in most hospitals. The “Bridge” clinic has also been valuable in training residents to provide medication treatment for SUDs within primary care. However, the outpatient experience in specialty care settings faced many scheduling challenges related to the COVID-19 pandemic, with reduced availability of preceptors, decreased number of in-person visits, and suspended group treatment. Optimizing outpatient addiction medicine training will be an ongoing goal in future rotation iterations. ONLINE RESOURCE URL: Rotation document: https://tinyurl.com/ MontefioreAddMedRotation.

Characterizing Disease Spreading via Visibility Graph Embedding

Gaining timely insights on real-world emergency events, such as infectious disease outbreaks, is critical for developing appropriate response strategies. In this work, we propose a data-driven approach to study the spreading dynamics of the global Covid-19 pandemic. Specifically, we aim to identify a set of most 'similar' geographic regions as proxies for making predictions on a targeted location. Example predictions include the number of new cases, number of hospitalizations, and number of deaths. Such predictions can be made at different levels of regional granularities, including city, county, and state levels. Our approach starts by transforming regional time series into graph representations using the natural visibility graph (NVG) model in order to capture their intrinsic trends and properties. These graphs are then projected onto a common embedding space using graph-level network embedding techniques. Essentially, each time series is converted as a data point in a feature embedding space, where spatial proximity indicates similarity among time series. Given a targeted region, our approach can identify the most 'relevant' geographic regions by finding its k-nearest neighbors in the embedding space. Subsequently, appropriate response strategies and policies (e.g., school shutdown, indoor dining restriction) can be adapted based on the success or failure experiences from relevant regions. Our approach will potentially provide valuable insights in mitigating the spreading of infectious disease. © 2021 IEEE.

Exploring extrinsic and intrinsic motivation of using User-Generated media in China: An empirical study on TikTok

During the COVID-19 period, governments have launched the "spatial distancing" policy to prevent virus transmission. With the shutdown of cultural and entertainment venues, information and communication technology (ICT) has taken on the role of alleviating the pressure caused by social distancing requirements, promoting more online activities, including user- generated media usage (UGM). In the absence of offline activities, UGM further proves the substantial economic benefits it brings. China, as the largest UGM market, provides unprecedented business opportunities for companies. Before implementing Chinese UGM market strategies, understanding users' motivations to use the media is essential. Therefore, this study investigates the extrinsic and intrinsic factors that affect the use and satisfaction of UGM in China. This study combines the Technology Acceptance Model (TAM) and Uses and Gratification Theory (U&G) to explore the motivations of using TikTok (Douyin), one of the most popular short video platforms that thrived during COVID- 19. The influences of perceived usefulness (PU), perceived ease of use (PEU), utilitarian motivations (UM), and experiential motivations (EM) on user's attitude, behavioral intention, and actual use. This study provides great value for companies to understand customer behaviors on TikTok (Douyin), thus better- implementing marketing strategies for achieving marketing goals, including customer involvement, communicating, and customer relationship management on this platform. © Peter Lang GmbH Internationaler Verlag der Wissenschaften Berlin 2021. All rights reserved.

[Application of remote "Internet+" interactive mode in the management of patients with hypertension during normalized epidemic prevention and control of COVID-19].

Objective: To explore the effect of remote "Internet+" interactive management strategy on blood pressure control in patients with hypertension during normalized epidemic prevention and control of COVID-19. Methods: This is a randomized controlled study. A total of 394 patients with hypertension who were treated in Chinese People's Liberation Army General Hospital from October 2019 to December 2020 were randomly divided into experimental group (197 cases) and control group (197 cases). The experimental group adopted remote "Internet+" interaction mode to carry out remote blood pressure intervention, and the control group received traditional blood pressure control mode, and the intervention time was 6 months. Evaluation indicators included blood pressure level, blood pressure lowering speed, time to target blood pressure, blood pressure measurement times, communication times with doctors, medication compliance, blood pressure measurement compliance and disease awareness after 6 months of intervention. The evaluation indexes of the two groups were compared, and the bivariate Pearson correlation analysis was used to explore the relationship between the speed of blood pressure reduction and the times of blood pressure measurement and doctor communication in all patients. Results: A total of 394 patients with hypertension were included in this study, including 209 males, aged (67.6±2.8) years old. After 6 months of intervention, the systolic and diastolic blood pressure of the two groups were both lower than the baseline blood pressure before intervention (both P<0.05), the systolic blood pressure ((125.7±11.7) mmHg (1 mmHg=0.133 kPa) vs. (132.6±12.9) mmHg, P<0.001) and diastolic blood pressure ((72.4±10.7) mmHg vs. (79.8±11.6) mmHg, P<0.001) in the experimental group were lower than those in the control group. The blood pressure reduction speed of the experimental group was faster than that of the control group ((18.63±1.59) mmHg/d vs. (13.26±2.85) mmHg/d, P<0.001), and the time to reach the target blood pressure in the experimental group was shorter than that in the control group ((23.69±2.93) d vs. (47.12±5.81) d, P<0.001). Compared with the control group, the blood pressure measurement times ((0.98±0.13) times/d vs. (0.20±0.40) times/d, P<0.05) and the number of communications with doctors ((0.97±0.16) times/week vs. (0.12±0.32) times/week, P<0.05) were significantly higher in the experimental group. Correlation analysis showed that the speed of blood pressure reduction was positively correlated with the number of blood pressure measurements (r=0.419, P<0.01) and the number of communications with doctors (r=0.857, P<0.01). The proportion of standardized medication (93.91% (185/197) vs. 51.78% (102/197), P<0.001), timely measurement (97.46% (192/197) vs. 47.21% (93/197), P<0.001) and high-degree disease awareness (94.42% (186/197) vs. 49.24% (97/197), P<0.001) were significantly higher in the experimental group than those in the control group. Conclusions: The remote "Internet+" interactive management strategy can effectively improve patients' blood pressure control. The doctor-patient interaction can improve medication compliance and measurement compliance of patients, and help shorten the time to reach the target blood pressure.

Beyond Entertainment: Unpacking Danmaku and Comments' Role of Information Sharing and Sentiment Expression in Online Crisis Videos

Online videos are playing an increasingly important role in timely information dissemination especially during public crises. Video commentary, synchronous or asynchronous, is indispensable in viewers' engagement and participation, and may in turn contribute to video with additional information and emotions. Yet, the roles of video commentary in crisis communications are largely unexplored, which we believe that an investigation not only provides timely feedback but also offers concrete guidelines for better information dissemination. In this work, we study two distinct commentary features of online videos: traditional asynchronous comments and emerging synchronous danmaku. We investigate how users utilize these two features to express their emotions and share information during a public health crisis. Through qualitative analysis and applying machine learning techniques on a large-scale danmaku and comment dataset of Chinese COVID-19-related videos, we uncover the distinctive roles of danmaku and comments in crisis communication, and propose comprehensive taxonomies for information themes and emotion categories of commentary. We also discover the unique patterns of crisis communications presented by danmaku, such as collective emotional resonance and style-based highlighting for emphasizing critical information. Our study captures the unique values and salient features of the emerging commentary interfaces, in particular danmaku, in the context of crisis videos, and further provides several design implications to enable more effective communications through online videos to engage and empower users during crises. © 2021 ACM.

Dynamic analysis of single-file pedestrian movement with maintaining social distancing in times of pandemic

In order to uncover the characteristics of pedestrian movement under different social distancing measures, we performed a series of single-file experiments considering two types of social distancing measures, namely 1 m and 2 m, and compared them with normal experiments conducted before Covid-19. Firstly, the findings indicate that social distancing measures do make pedestrians keep a greater distance, but there are social distance violations. When the density is greater than 0.23 m(-1), pedestrians have more violations under the measure of 2 m than that of 1 m at the same density. Although the typical stop-and-go wave is still observed in social distancing experiments, the increase in social distancing causes pedestrian stopping behavior to occur at lower density, and shortens the density range of the transition from free flow to jammed flow. Moreover, the headway-speed relation under social distancing measures is not a simple horizontal displacement of that under normal conditions. Although their free speeds are similar, the increase in social distancing makes pedestrians need longer adaption time and more space to transform the motion state. Finally, fundamental diagrams are obtained, and the maximum specific flows for social distancing of 1 m and 2 m is 0.62 s(-1) and 0.53 s(-1), respectively. Apart from the comparison with normal conditions, the comparison with the two-dimensional social distancing experiments shows that pedestrians are more able to comply with the prescribed social distance and stop less in single-file movement. These enrichments offer empirical data of pedestrian movement under different social distancing measures and benefit pedestrian modeling during pandemics.

Polymer Composites Completely Derived from Waste: The Crystalline Structure and the Mechanical Enhancement Effect

During the recent COVID-19 pandemic, wearing face masks has become the simplest and most effective way to block the spread of the disease. However, after people wear masks, thousands of tons of medical waste caused by used disposable masks is being generated every day in the world, causing great pressure on the environment. Herein, polymer composites completely derived from waste are manufactured by simple melt blending of disposable mask fragments (mask polypropylene, short for mPP) and discarded loofah sponge (LS). LS was used as a reinforcing agent for the composites because of its unique micron channel structure. The crystalline structure and the mechanical enhancement effect of the composites were investigated. LS powders played a role in promoting the crystallization of mPP by expediting the crystalline nucleation, leading to an improvement in the amount of crystalline nuclei. After being incorporated within the mPP with high fluidity, the LS fiber changing from hollow to solid provides reinforcement for composite materials. With 12 wt % LS loading, the tensile strength of the composites was increased by 326%. The findings may open a way for high-value utilization of disposable masks. © 2021 American Chemical Society.

Educational purgatory: Medical education in the era of covid-19

Medical education and technological adaptations in the time of COVID-19 affect medical students at all levels of training, though in different ways. First- and second-year students have fully transitioned to online learning with minimal disruption. Third-year students are likely the most affected due to major restructuring of their curriculum and the sudden halt in clinical activities on core rotations that may be critical to their residency choice. Fourth-year students’ medical school education component stands to be least affected;however, disruptions to their training will extend into their first year of residency. Technological adaptations will likely play a larger role in medical education and practice in the months ahead. © 2020, British Columbia Medical Association. All rights reserved.