Forecasting, capturing and activation of carbon-dioxide (CO$_2$): Integration of Time Series Analysis, Machine Learning, and Material Design (preprint)

This study provides a comprehensive time series analysis of daily industry-specific, country-wise CO$_2$ emissions from January 2019 to February 2023. The research focuses on the Power, Industry, Ground Transport, Domestic Aviation, and International Aviation sectors in European countries (EU27 & UK, Italy, Germany, Spain) and India, utilizing near-real-time activity data from the Carbon Monitor research initiative. To identify regular emission patterns, the data from the year 2020 is excluded due to the disruptive effects caused by the COVID-19 pandemic. The study then performs a principal component analysis (PCA) to determine the key contributors to CO$_2$ emissions. The analysis reveals that the Power, Industry, and Ground Transport sectors account for a significant portion of the variance in the dataset. A 7-day moving averaged dataset is employed for further analysis to facilitate robust predictions. This dataset captures both short-term and long-term trends and enhances the quality of the data for prediction purposes. The study utilizes Long Short-Term Memory (LSTM) models on the 7-day moving averaged dataset to effectively predict emissions and provide insights for policy decisions, mitigation strategies, and climate change efforts. During the training phase, the stability and convergence of the LSTM models are ensured, which guarantees their reliability in the testing phase. The evaluation of the loss function indicates this reliability. The model achieves high efficiency, as demonstrated by $R^2$ values ranging from 0.8242 to 0.995 for various countries and sectors. Furthermore, there is a proposal for utilizing scandium and boron/aluminium-based thin films as exceptionally efficient materials for capturing CO$_2$ (with a binding energy range from -3.0 to -3.5 eV). These materials are shown to surpass the affinity of graphene and boron nitride sheets in this regard.

Angina Bullosa Haemorrhagica in COVID 19: A Diagnostic Conundrum. Case Report and Review of Literature

Oral manifestations of COVID-19 are amongst the most obscure and ill-reported. Of these, angina bullosa haemorrhagica is amongst the rarest. Only 2 cases of angina bullosa haemorrhagica in COVID-19 patients have been reported in literature. Angina bullosa haemorrhagica (ABH) is an enigmatic, abstruse condition represented by sudden onset of painful subepithelial, mucosal blood-filled vesicles and bullae in the oral cavity. It is not attributed to any systemic conditions, blood dyscracias or other well-known dermatological pathologies. The occurrence of these lesions in patients of COVID-19 suggests that the underlying pathology of the latter may predispose to ABH and thus help in shedding some light onto the pathogenesis of this obscure disease. Herein we present 2 cases of ABH in patients of COVID-19 within a few weeks of the resolution of the latter. Both patients reported that they had never had this condition before and that this was the first presentation of the symptom. A review of literature shows that the etiopathogenesis of ABH is ambiguous at best and that the pathology underlying the oral manifestation of COVID-19 may well be applicable to ABH as well. Various mechanisms have been proposed to cause oral manifestations in COVID-19 patients. These include imbalance in the RAS pathway causing mucosal disruption, immune dysregulation, deranged cellular immune mechanism and disruption of local immune mechanisms. Since ABH has been reported in COVID 19, it is plausible that some of the mechanisms underlying the pathogenesis of oral manifestations may explain the pathogenesis of ABH.

Angina Bullosa Haemorrhagica in COVID 19: A Diagnostic Conundrum. Case Report and Review of Literature.

Oral manifestations of COVID-19 are amongst the most obscure and ill-reported. Of these, angina bullosa haemorrhagica is amongst the rarest. Only 2 cases of angina bullosa haemorrhagica in COVID-19 patients have been reported in literature. Angina bullosa haemorrhagica (ABH) is an enigmatic, abstruse condition represented by sudden onset of painful subepithelial, mucosal blood-filled vesicles and bullae in the oral cavity. It is not attributed to any systemic conditions, blood dyscracias or other well-known dermatological pathologies. The occurrence of these lesions in patients of COVID-19 suggests that the underlying pathology of the latter may predispose to ABH and thus help in shedding some light onto the pathogenesis of this obscure disease. Herein we present 2 cases of ABH in patients of COVID-19 within a few weeks of the resolution of the latter. Both patients reported that they had never had this condition before and that this was the first presentation of the symptom. A review of literature shows that the etiopathogenesis of ABH is ambiguous at best and that the pathology underlying the oral manifestation of COVID-19 may well be applicable to ABH as well. Various mechanisms have been proposed to cause oral manifestations in COVID-19 patients. These include imbalance in the RAS pathway causing mucosal disruption, immune dysregulation, deranged cellular immune mechanism and disruption of local immune mechanisms. Since ABH has been reported in COVID 19, it is plausible that some of the mechanisms underlying the pathogenesis of oral manifestations may explain the pathogenesis of ABH.

Detection of SARS-CoV-2 in a free ranging leopard (Panthera pardus fusca) in India.

We report an incidence of natural infection of SARS-CoV-2 in free-ranging Indian leopard (Panthera pardus fusca). The case was detected during routine screening. Post-mortem and laboratory examination suggested virus-induced interstitial pneumonia. Viral genome could be detected in various organs including brain, lung, spleen, and lymph nodes by real-time PCR. Whole-genome sequence analysis confirmed infection of Pango lineage B.1.617.2 of SARS-CoV-2. Till now, only Asiatic lions have been reported to be infected by SARS-CoV-2 in India. Infections in animals were detected during peak phase of pandemic and all the cases were captive with close contacts with humans, whereas the present case was observed when human cases were significantly low. No tangible evidence linked to widespread infection in the wild population and the incidence seems to be isolated case. High nucleotide sequence homology with prevailing viruses in humans suggested spillover infection to the animal. This report underlines the need for intensive screening of wild animals for keeping track of the virus evolution and development of carrier status of SARS-CoV-2 among wildlife species. Supplementary Information: The online version contains supplementary material available at 10.1007/s10344-022-01608-4.

Structure Analysis and Molecular Simulation Study of ACC Deaminase Mutants from Pseudomonas sp., an Endophyte in Reducing Abiotic Stress in Plants

[...]heme-copper oxidases from Rhodobacter sphaeroides underwent single amino acid substitutions, including N139D, which resulted in the elimination of proton pumping activity and an increase in steady-state activity rather than an inhibitory effect (Pawate et al. 2002). [...]ACC deaminase must begin the cyclopropane ring opening reaction without the availability of an R-carbanionic intermediate. [...]ACC deaminase from Pseudomonas sp. Site-specific docking with ACC was performed for each mutated structure, and the T199S mutant produced binding energy of -4.3 kcal/mol, whereas the E295G mutant was found to have a binding energy of -4.9 kcal/mol. [...]the E295G mutant, in which glutamic acid is substituted with glycine at the 295th position, was chosen

A review on the effect of micro- and nano-plastics pollution on the emergence of antimicrobial resistance

The recent upsurge in the studies on micro/nano plastics and antimicrobial resistance genes has proven their deleterious effects on the environmental and human health. Till-date, there is a scarcity of studies on the interactions of these two factors and their combined influence. The interaction of microplastics has led to the formation of new plastics namely plastiglomerates, pyroplastics. and anthropoquinas. It has long been ignored that the occurrence of microplastics has become a breeding ground for the emergence of antimicrobial resistance genes. Evidently microplastics are also associated with the occurrence of other pollutants such as polyaromatic hydrocarbons and pesticides. The increased use of antibiotics (after Covid breakout) has further elevated the detrimental effects on human health. Therefore, this study highlights the relation of microplastics with antibiotic resistance generation. The factors such as uncontrolled use of antibiotics and negligent plastic consumption has been evaluated. Furthermore, the future research prospective was provided that can be helpful in correctly identifying the seriousness of the environmental occurrence of these pollutants.

Treatment with anti-inflammatory viral serpin modulates immuno-thrombotic responses and improves outcomes in SARS-CoV-2 infected mice (preprint)

Severe acute respiratory distress syndrome (ARDS) during SARS-CoV-2 (severe acute respiratory syndrome coronavirus-2) infection, manifests as uncontrolled lung inflammation and systemic thrombosis with high mortality. Anti-viral drugs and monoclonal antibodies can reduce COVID-19 severity if administered in the early viremic phase, but treatments for later stage immuno-thrombotic syndrome and long COVID are limited. Serine protease inhibitors (SERPINS) regulate activated proteases during thrombotic, thrombolytic and immune responses. The myxoma poxvirus-derived Serp-1 protein is a secreted immunomodulatory serpin that targets activated coagulation and complement protease pathways as part of a self-defense strategy to combat viral clearance by the innate immune system. When purified and utilized as an anti-immune therapeutic, Serp-1 is effective as an anti-inflammatory drug in multiple animal models of inflammatory lung disease and vasculitis. Here, we describe systemic treatment with purified PEGylated Serp-1 (PEGSerp-1) as a therapy for immuno-thrombotic complications during ARDS. Treatment with PEGSerp-1 in two distinct mouse-adapted SARS-CoV-2 models in C57Bl/6 and BALB/c mice reduced lung and heart inflammation, with improved clinical outcomes. PEGSerp-1 significantly reduced M1 macrophage invasion in the lung and heart by modifying urokinase-type plasminogen activator receptor (uPAR) and complement membrane attack complex (MAC). Sequential changes in urokinase-type plasminogen activator receptor (uPAR) and serpin gene expression were observed in lung and heart with PEGSerp-1 treatment. PEGSerp-1 is a highly effective immune-modulator with therapeutic potential for treatment of severe viral ARDS with additional potential to reduce late SARS-CoV-2 complications related to immune-thrombotic events that persist during long COVID. Significance: Severe acute respiratory distress syndrome (ARDS) in SARS-CoV-2 infection manifests as uncontrolled tissue inflammation and systemic thrombosis with high mortality. Anti-viral drugs and monoclonal antibodies reduce COVID-19 severity if administered early, but treatments for later stage immuno-thrombosis are limited. Serine protease inhibitors (SERPINS) regulate thrombotic, thrombolytic and complement pathways. We investigate here systemic treatment with purified poxvirus-derived PEGSerp-1 as a therapeutic for immuno-thrombotic complications in viral ARDS. PEGSerp-1 treatment in two mouse-adapted SARS-CoV-2 models (C57Bl/6 and BALB/c) significantly reduced lung and heart inflammation and improved clinical outcomes, with sequential changes in thrombolytic (uPAR) and complement expression. PEGSerp-1 is a highly effective immune-modulator with therapeutic potential for immune-thrombotic complications in severe viral ARDS and has potential benefit for long COVID.

ABV-CoViD: An Ensemble Forecasting Model to Predict Availability of Beds and Ventilators for COVID-19 Like Pandemics.

Recently, healthcare stakeholders have orchestrated steps to strengthen and curb the COVID-19 wave. There has been a surge in vaccinations to curb the virus wave, but it is crucial to strengthen our healthcare resources to fight COVID-19 and like pandemics. Recent researchers have suggested effective forecasting models for COVID-19 transmission rate, spread, and the number of positive cases, but the focus on healthcare resources to meet the current spread is not discussed. Motivated from the gap, in this paper, we propose a scheme, ABV-CoViD (Availibility of Beds and Ventilators for COVID-19 patients), that forms an ensemble forecasting model to predict the availability of beds and ventilators (ABV) for the COVID-19 patients. The scheme considers a region-wise demarcation for the allotment of beds and ventilators (BV), termed resources, based on region-wise ABV and COVID-19 positive patients (inside the hospitals occupying the BV resource). We consider an integration of artificial neural network (ANN) and auto-regressive integrated neural network (ARIMA) model to address both the linear and non-linear dependencies. We also consider the effective wave spread of COVID-19 on external patients (not occupying the BV resources) through a [Formula: see text]- ARNN model, which gives us long-term complex dependencies of BV resources in the future time window. We have considered the COVID-19 healthcare dataset on 3 USA regions (Illinois, Michigan, and Indiana) for testing our ensemble forecasting scheme from January 2021 to May 2022. We evaluated our scheme in terms of statistical performance metrics and validated that ensemble methods have higher accuracy. In simulation, for linear modelling, we considered the [Formula: see text] model, and [Formula: see text] model for ANN modelling. We considered the [Formula: see text](12,6) forecasting. On a population of 2,93,90,897, the obtained mean absolute error (MAE) on average for 3 regions is 170.5514. The average root means square error (RMSE) of [Formula: see text]-ARNN is 333.18, with an accuracy of 98.876%, which shows the scheme's efficacy in ABV measurement over conventional and manual resource allocation schemes.

Application of surfactants for better tomorrow

Surfactants are the important class of amphiphilic species, which consists of both hydrophilic as well as hydrophobic part. They are characterized by some important properties like critical micelle concentration (CMC), charge, hydrophile-lypophile balance (HLB), aggregation, and chemical structure, which make them good emulsifying, dispersing and foaming agents. Presently, the global demand of the surfactants is on the peak due to their increased applications in detergents, paints, food emulsion, biotechnological processes, biosciences, pharmaceuticals, cosmetic products, etc. In order to prevent Corona pandemic disease, WHO and other regulatory authorities have recommended frequent use of soaps and sanitizers that makes surfactants an important class of species to be explored more in terms of their applications.

Analysis of predictors and outcomes of COVID-19 patients requiring ICU admission from COVID 19 (preprint)

BackgroundSevere Corona virus disease (COVID-19) is associated with high mortality. Although single centre intensive care units (ICU) have reported clinical characteristics and outcomes, no large scale multicentric study from India has been published. The present retrospective, multi-centre study was aimed to describe the predictors and outcomes of COVID-19 patients requiring ICU admission from COVID-19 Registry of Indian council of Medical Research (ICMR), India.MethodsProspectively collected data from multiple participating institutions was entered in the electronic National Clinical Registry of COVID 19. We enrolled patients aged>18 years with COVID-19 pneumonia requiring ICU admission between March 2020 and August 2021. Exclusion criteria were negative RT PCR, death within 24 hours of ICU admission, or patients with incomplete data in the registry Their demographic characteristics, laboratory variables, ICU severity indices, treatment strategies and outcomes were analysed.ResultsA total of 5865 patients, with mean age 56±15 years, with 3840/5865 (65.4%) men, were enrolled in the ICMR registry.. Overall mortality was 2535/5865 (43.5%). Non-survivors were older than survivors (58.2±15.4 years vs 53.6 ±14.7 years; P=0.001). Non-survivors had multiple comorbidities (n=1951, 52.9%) with hypertension (47.2%) and diabetes (45.6%) being the most common, higher creatinine (1.6 ± P=0.001, high D-dimer (1.56 vs 1.37, P=0.001), higher CT severity index (16.8±5.2 vs 13.5 ±5.47 ) compared to  survivors. Non survivors had longer hospital and ICU stay (P=0.001). On multivariate regression analysis, high NLR (HR 1.017, 95% CI 1.005- 1.029, P=0.001), high CRP (HR 1.008, 95% CI 1.006- 1.010, P=0.001), high D dimer ((HR 1.089, 95% CI 1.065- 1.113, P=0.001) were associated with mechanical ventilation while younger age, (HR 0.974, CI 0.965-0.983, p=0.001), high D dimer (HR-1.014, CI 1.001-1.027, P=0.035) and use of prophylactic LMWH (HR 0.647, CI 0.527-0.794, p=0.001) were independently associated with mortality. ConclusionIn this large retrospective study of 5865 critically ill COVID 19 patients admitted to ICU, overall mortality was 2535/5865 (43.5%). Age, high D dimer, CT Severity score and use of prophylactic LMWH were independently associated with mortality. 

Interplay of Nutrition and Psychoneuroendocrineimmune Modulation: Relevance for COVID-19 in BRICS Nations.

The consequences of COVID-19 are not limited to physical health deterioration; the impact on neuropsychological well-being is also substantially reported. The inter-regulation of physical health and psychological well-being through the psychoneuroendocrineimmune (PNEI) axis has enduring consequences in susceptibility, treatment outcome as well as recuperation. The pandemic effects are upsetting the lifestyle, social interaction, and financial security; and also pose a threat through perceived fear. These consequences of COVID-19 also influence the PNEI system and wreck the prognosis. The nutritional status of individuals is also reported to have a determinative role in COVID-19 severity and convalescence. In addition to energetic demand, diet also provides precursor substances [amino acids (AAs), vitamins, etc.] for regulators of the PNEI axis such as neurotransmitters (NTs) and immunomodulators. Moreover, exaggerated immune response and recovery phase of COVID-19 demand additional nutrient intake; widening the gap of pre-existing undernourishment. Mushrooms, fresh fruits and vegetables, herbs and spices, and legumes are few of such readily available food ingredients which are rich in protein and also have medicinal benefits. BRICS nations have their influences on global development and are highly impacted by a large number of confirmed COVID-19 cases and deaths. The adequacy and access to healthcare are also low in BRICS nations as compared to the rest of the world. Attempt to combat the COVID-19 pandemic are praiseworthy in BRICS nations. However, large population sizes, high prevalence of undernourishment (PoU), and high incidence of mental health ailments in BRICS nations provide a suitable landscape for jeopardy of COVID-19. Therefore, appraising the interplay of nutrition and PNEI modulation especially in BRICS countries will provide better understanding; and will aid in combat COVID-19. It can be suggested that the monitoring will assist in designing adjunctive interventions through medical nutrition therapy and psychopsychiatric management.

Systemic infection of SARS-CoV-2 in free ranging Leopard (Panthera pardus fusca) in India (preprint)

We report patho-morphological and virological characterization of SARS-CoV-2 in naturally infected, free ranging Indian Leopard (Panthera pardus fusca). Whole genome sequence analysis confirmed infection of Delta variant of SARS-CoV-2, possibly spill over from humans, but the case was detected when infection level had dropped significantly in human population. This report underlines the need for intensive screening of wild animals for keeping track of the virus evolution and development of carrier status of SARS-CoV-2 among wildlife species.

Trends in mitigation of industrial waste: Global health hazards, environmental implications and waste derived economy for environmental sustainability.

Majority of industries, in order to meet the technological development and consumer demands generate waste. The untreated waste spreads out toxic and harmful substances in the environment which serves as a breeding ground for pathogenic microorganisms thus causing severe health hazards. The three industrial sectors namely food, agriculture, and oil industry are among the primary organic waste producers that affect urban health and economic growth. Conventional treatment generates a significant amount of greenhouse gases which further contributes to global warming. Thus, the use of microbes for utilization of this waste, liberating CO2 offers an indispensable tool. The simultaneous production of value-added products such as bioplastics, biofuels, and biosurfactants increases the economics of the process and contributes to environmental sustainability. This review comprehensively summarized the composition of organic waste generated from the food, agriculture, and oil industry. The linkages between global health hazards of industrial waste and environmental implications have been uncovered. Stare-of-the-art information on their subsequent utilization as a substrate to produce value-added products through bio-routes has been elaborated. The research gaps, economical perspective(s), and future research directions have been identified and discussed to strengthen environmental sustainability.

Management of Adolescent Three-Part Lateral Triplane Ankle Fracture with Ipsilateral Shaft of Tibia Fracture and Intact Fibula in COVID Pandemic: A Case Report with Review of Literature.

INTRODUCTION: Triplane fracture of ankle is a rare adolescent injury. Its association with ipsilateral tibial shaft fracture is very uncommon in pediatric orthopedic traumatology and rarely reported in the literature till date. Timely diagnosis and management is required to optimize the outcome and avoid complications. CASE REPORT: This is a case of a 14-year-old male who sustained a twisting injury to his right leg during early phase of COVID-19 pandemic. He sustained a three-part lateral triplane fracture of the ankle with a concomitant displaced spiral fracture of the shaft of the right tibia. He underwent close reduction under fluoroscopy and above-knee casting for 10 weeks followed patellar tendon weight-bearing cast for 4 weeks. Both fractures healed uneventfully in 14 weeks with patient returning to full activities in 22 weeks. CONCLUSION: The ankle injury in adolescent age group (12-15 years) can easily be missed in the presence of the more obvious tibial fracture and therefore, we recommend ankle assessment of all patients with tibial shaft fractures in this age group both clinically and radiologically.

Approach to dealing with orthopedic trauma patients at semi-urban centers during COVID-19 pandemic: An insight from a developing country

Coronavirus disease 2019 (COVID-19) has wreaked havoc on global health care. Although tertiary care hospitals and major trauma centers in developing countries are well equipped to render trauma care safely, this is not the case in district or nonmetropolitan small centers. Herein, we intend to outline the problems currently being faced by these small peripheral centers and their carefully crafted strategy in managing trauma victims. We also proposed some recommendations that are hoped to boost the endeavor to work in a sound and effective milieu.

Fulminant necrotising amoebic colitis after corticosteroid therapy for severe COVID-19.

Acute fulminant necrotising colitis is an uncommon presentation of amoebiasis, which can be precipitated after corticosteroid therapy. Clinicians treating patients with COVID-19 with corticosteroid therapy should be familiar with this condition to avoid delay in diagnosis. The disease is associated with high mortality, and prompt diagnosis and management are essential for salvaging patients. We report successful management of a patient who developed this complication following administration of steroids for COVID-19.

CASE-CF: Context Aware Smart Epidemic Control Framework.

Novel Coronavirus (COVID-19) has become one of the deadliest pandemics that has affected almost all the nations in the world. Lockdown and systematic re-opening of shopping malls, offices, etc. is still one of the major weapons against this virus. However, the government and medical agencies take long time to reopen the places due to risks involved in this deadly virus. The delay to reopen places has resulted in sharp decline in the growth of economy. In this paper a current context aware framework is proposed which uses multiple inputs for a specific region to decide whether to open it or not. The proposed framework used series of deep neural network models to generate recommendations specific to a particular region. Most of the inputs are real-time and readily available with the government. The main aim is to develop framework which can be used in any kind of pandemic even in small region to easily contain it. However, it has been tested using opensource data available for COVID-19. Data was crawled from web for 22 districts of Haryana state of India. Experimental result proved the efficiency of proposed framework.

Profile of Mucormycosis Cases from a Network of Hospitals in North India Amidst COVID-19 Pandemic (preprint)

Incidence of mucormycosis suddenly surged in India after the second wave of COVID-19. This is a crippling disease and needs to be studied in detail to understand the disease, its course, and the outcomes. Between 1st March and 15th July 2021, our network of hospitals in North India received a total of 155 cases of COVID-associated mucormycosis cases as all of them reported affliction by COVID-19 earlier or concurrent. Their records were retrieved from the Electronic Health Records system of the hospitals and their demographics, clinical features, treatments, and outcomes were studied. More than 80% (125 cases) had proven disease and the remaining 30 were categorized as possible mucormycosis as per the EORTC criteria. More than two-thirds (69.0%) of the cases were males and the mean age was 53 years for either sex. Nearly two-thirds (64.5%) had symptoms of nose and jaws and 42.6% had eye involvement. Some had multiple symptoms. As many as 78.7% had diabetes and 91.6% gave history of use of steroids during COVID-19 treatment. The primary surgery was functional endoscopic sinus surgery (FESS) (83.9%). Overall mortality was 16.8%, which is one-and-a-half times the mortality in hospitalized COVID-19 patients in the corresponding population. Occurrence of mucormycosis was associated with diabetes and use of steroids, but mortality was not associated with either of them. Cases undergoing surgery and on antifungal had steeply lower mortality (11.9% vs. 50.0%, P < 0.001) than those who were exclusively on antifungal drugs. Treatment by different drugs did not make much of a difference in mortality.

Disaster relief supply chain design for personal protection equipment during the COVID-19 pandemic.

The global epidemic caused by novel coronavirus continues to be a crisis in the world and a matter of concern. The way the epidemic has wreaked havoc on the international level has become difficult for the healthcare systems to supply adequately personal protection equipment for medical personnel all over the globe. In this paper, considering the COVID-19 outbreak, a multi-objective, multi-product, and multi-period model for the personal protection equipment demands satisfaction aiming to optimize total cost and shortage, simultaneously, is developed. The model is embedded with instances and validated by both modern and classic multi-objective metaheuristic algorithms. Moreover, the Taguchi method is exploited to set the metaheuristic into their best performances by finding their parameters' optimum level. Furthermore, fifteen test examples are designed to prove the established PPE supply chain model and tuned algorithms' applicability. Among the test examples, one is related to a real case study in Iran. Finally, metaheuristics are evaluated by a series of related metrics through different statistical analyses. It can be concluded from the obtained results that solution methods are practical and valuable to achieve the efficient shortage level and cost.

Effect of recirculation zones on the ventilation of a public washroom (preprint)

Air-borne transmission can pose a major risk of infection spread in enclosed spaces. Venting the air out using exhaust fans and ducts is a common approach to mitigate the risk. In this work, we study the air flow set up by an exhaust fan in a typical shared washroom that can be a potential hot spot for COVID-19 transmission. The primary focus is on the regions of recirculating flow that can harbor infectious aerosol for much longer than the well-ventilated parts of the room. Computational fluid dynamics is used to obtain the steady state air flow field, and Lagrangian tracking of particles give the spatial and temporal distribution of infectious aerosol in the domain. It is found that the washbasin located next to the door is in a prominent recirculation zone, and particles injected in this region take much longer to be evacuated. The ventilation rate is found to be governed by the air residence time in the recirculation zone, and it is much higher than the time scale based on fully-mixed reactor model of the room. Increasing the fan flow rate can reduce the ventilation time, but cannot eliminate the recirculation zones in the washroom.