Showing papers by "China Three Gorges University published in 2020"

Clinical characteristics of novel coronavirus cases in tertiary hospitals in Hubei Province.

Abstract: BACKGROUND: The 2019 novel coronavirus (2019-nCoV) causing an outbreak of pneumonia in Wuhan, Hubei province of China was isolated in January 2020. This study aims to investigate its epidemiologic history, and analyze the clinical characteristics, treatment regimens, and prognosis of patients infected with 2019-nCoV during this outbreak. METHODS: Clinical data from 137 2019-nCoV-infected patients admitted to the respiratory departments of nine tertiary hospitals in Hubei province from December 30, 2019 to January 24, 2020 were retrospectively collected, including general status, clinical manifestations, laboratory test results, imaging characteristics, and treatment regimens. RESULTS: None of the 137 patients (61 males, 76 females, aged 20-83 years, median age 57 years) had a definite history of exposure to Huanan Seafood Wholesale Market. Major initial symptoms included fever (112/137, 81.8%), coughing (66/137, 48.2%), and muscle pain or fatigue (44/137, 32.1%), with other, less typical initial symptoms observed at low frequency, including heart palpitations, diarrhea, and headache. Nearly 80% of the patients had normal or decreased white blood cell counts, and 72.3% (99/137) had lymphocytopenia. Lung involvement was present in all cases, with most chest computed tomography scans showing lesions in multiple lung lobes, some of which were dense; ground-glass opacity co-existed with consolidation shadows or cord-like shadows. Given the lack of effective drugs, treatment focused on symptomatic and respiratory support. Immunoglobulin G was delivered to some critically ill patients according to their conditions. Systemic corticosteroid treatment did not show significant benefits. Notably, early respiratory support facilitated disease recovery and improved prognosis. The risk of death was primarily associated with age, underlying chronic diseases, and median interval from the appearance of initial symptoms to dyspnea. CONCLUSIONS: The majority of patients with 2019-nCoV pneumonia present with fever as the first symptom, and most of them still showed typical manifestations of viral pneumonia on chest imaging. Middle-aged and elderly patients with underlying comorbidities are susceptible to respiratory failure and may have a poorer prognosis.

Characteristics of Ocular Findings of Patients With Coronavirus Disease 2019 (COVID-19) in Hubei Province, China.

Abstract: Importance While the outbreak of coronavirus disease 2019 (COVID-19) has resulted in more than 100 000 infected individuals in China and worldwide, there are few reports on the association of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with ocular abnormalities. Understanding ocular manifestations of patients with COVID-19 by ophthalmologists and others may facilitate the diagnosis and prevention of transmission of the disease. Objective To investigate ocular manifestations and viral prevalence in the conjunctiva of patients with COVID-19. Design, Setting, and Participants In this case series, patients with COVID-19 treated from February 9 to 15, 2020, at a hospital center in Hubei province, China, were retrospectively reviewed for ocular manifestations. During the period of treatment, the ocular signs and symptoms as well as results of blood tests and reverse transcriptase–polymerase chain reaction (RT-PCR) from nasopharyngeal and conjunctival swabs for SARS-CoV-2 were noted and analyzed. Main Outcomes and Measures Ocular signs and symptoms as well as results of blood tests and RT-PCR for SARS-CoV-2. Results Of the 38 included patients with clinically confirmed COVID-19, 25 (65.8%) were male, and the mean (SD) age was 65.8 (16.6) years. Among them, 28 patients (73.7%) had positive findings for COVID-19 on RT-PCR from nasopharyngeal swabs, and of these, 2 patients (5.2%) yielded positive findings for SARS-CoV-2 in their conjunctival as well as nasopharyngeal specimens. A total of 12 of 38 patients (31.6%; 95% CI, 17.5-48.7) had ocular manifestations consistent with conjunctivitis, including conjunctival hyperemia, chemosis, epiphora, or increased secretions. By univariate analysis, patients with ocular symptoms were more likely to have higher white blood cell and neutrophil counts and higher levels of procalcitonin, C-reactive protein, and lactate dehydrogenase than patients without ocular symptoms. In addition, 11 of 12 patients with ocular abnormalities (91.7%; 95% CI, 61.5-99.8) had positive results for SARS-CoV-2 on RT-PCR from nasopharyngeal swabs. Of these, 2 (16.7%) had positive results for SARS-CoV-2 on RT-PCR from both conjunctival and nasopharyngeal swabs. Conclusions and Relevance In this study, one-third of patients with COVID-19 had ocular abnormalities, which frequently occurred in patients with more severe COVID-19. Although there is a low prevalence of SARS-CoV-2 in tears, it is possible to transmit via the eyes.

Macroscopic Spontaneous Polarization and Surface Oxygen Vacancies Collaboratively Boosting CO2 Photoreduction on BiOIO3 Single Crystals

Abstract: Prompt recombination of photogenerated electrons and holes in bulk and on the surface of photocatalysts harshly impedes the photocatalytic efficiency. However, the simultaneous manipulation of photocharges in the two locations is challenging. Herein, the synchronous promotion of bulk and surface separation of photoinduced charges for prominent CO2 photoreduction by coupling macroscopic spontaneous polarization and surface oxygen vacancies (OVs) of BiOIO3 single crystals is reported. The oriented growth of BiOIO3 single-crystal nanostrips along the [001] direction, ensuing substantial well-aligned IO3 polar units, renders a large enhancement for the macroscopic polarization electric field, which is capable of driving the rapid separation and migration of charges from bulk to surface. Meanwhile the introduction of surface OVs establishes a local electric field for charge migration to catalytic sites on the surface of BiOIO3 nanostrips. Highly polarized BiOIO3 nanostrips with ample OVs demonstrate outstanding CO2 reduction activity for CO production with a rate of 17.33 µmol g-1 h-1 (approximately ten times enhancement) without any sacrificial agents or cocatalysts, being one of the best CO2 reduction photocatalysts in the gas-solid system reported so far. This work provides an integrated solution to governing charge movement behavior on the basis of collaborative polarization from bulk and surface.

Reverse Logistics Network Design for Effective Management of Medical Waste in Epidemic Outbreaks: Insights from the Coronavirus Disease 2019 (COVID-19) Outbreak in Wuhan (China)

Abstract: The outbreak of an epidemic disease may pose significant treats to human beings and may further lead to a global crisis. In order to control the spread of an epidemic, the effective management of rapidly increased medical waste through establishing a temporary reverse logistics system is of vital importance. However, no research has been conducted with the focus on the design of an epidemic reverse logistics network for dealing with medical waste during epidemic outbreaks, which, if improperly treated, may accelerate disease spread and pose a significant risk for both medical staffs and patients. Therefore, this paper proposes a novel multi-objective multi-period mixed integer program for reverse logistics network design in epidemic outbreaks, which aims at determining the best locations of temporary facilities and the transportation strategies for effective management of the exponentially increased medical waste within a very short period. The application of the model is illustrated with a case study based on the outbreak of the coronavirus disease 2019 (COVID-19) in Wuhan, China. Even though the uncertainty of the future COVID-19 spread tendency is very high at the time of this research, several general policy recommendations can still be obtained based on computational experiments and quantitative analyses. Among other insights, the results suggest installing temporary incinerators may be an effective solution for managing the tremendous increase of medical waste during the COVID-19 outbreak in Wuhan, but the location selection of these temporary incinerators is of significant importance. Due to the limitation on available data and knowledge at present stage, more real-world information are needed to assess the effectiveness of the current solution.

Two-Dimensional (2D) Covalent Organic Framework as Efficient Cathode for Binder-free Lithium-Ion Battery.

Abstract: Searching new organic cathode materials to address the issues of poor cycle stability and low capacity in lithium ion batteries (LIBs) is very important and highly desirable. In this research, a 2D boroxine-linked chemically-active pyrene-4,5,9,10-tetraone (PTO) covalent organic framework (2D PPTODB COFs) was synthesized as an organic cathode material with remarkable electrochemical properties, including high electrochemical activity (four redox electrons), safe oxidation potential window (between 2.3 and 3.08 V vs. Li/Li+ ), superb structural/chemical stability, and strong adhesiveness. A binder-free cathode was obtained by mixing 70 wt % PPTODB and 30 wt % carbon nanotubes (CNTs) as a conductive additive. Promoted by the fast kinetics of electrons/ions, high electrochemical activity, and effective π-π interaction between PPTODB and CNTs, LIBs with the as-prepared cathode exhibited excellent electrochemical performance: a high specific capacity of 198 mAh g-1 , a superb rate ability (the capacity at 1000 mA g-1 can reach 76 % of the corresponding value at 100 mA g-1 ), and a stable coulombic efficiency (≈99.6 % at the 150th cycle). This work suggests that the concept of binder-free 2D electroactive materials could be a promising strategy to approach energy storage with high energy density.

A Metal‐Free Donor–Acceptor Covalent Organic Framework Photocatalyst for Visible‐Light‐Driven Reduction of CO2 with H2O

Abstract: Visible-light-driven CO2 reduction to valuable chemicals without sacrificial agents and cocatalysts remains challenging, especially for metal-free photocatalytic systems. Herein, a novel donor-acceptor (D-A) covalent organic framework (CT-COF) was constructed by the Schiff-base reaction of carbazole-triazine based D-A monomers and possessed a suitable energy band structure, strong visible-light-harvesting, and abundant nitrogen sites. CT-COF as a metal-free photocatalyst could reduce CO2 with gaseous H2 O to CO as the main carbonaceous product with approximately stoichiometric O2 evolution under visible-light irradiation and without cocatalyst. The CO evolution rate (102.7 μmol g-1 h-1 ) was 68.5 times that of g-C3 N4 under the same conditions. In situ Fourier-transform (FT)IR analysis indicated that CT-COF could adsorb and activate the CO2 and H2 O molecules and that COOH* species may be a key intermediate. DFT calculations suggested that nitrogen atoms in the triazine rings may be photocatalytically active sites.

Deep Learning Method Based on Gated Recurrent Unit and Variational Mode Decomposition for Short-Term Wind Power Interval Prediction

Abstract: Wind power interval prediction (WPIP) plays an increasingly important role in evaluations of the uncertainty of wind power and becomes necessary for managing and planning power systems. However, the intermittent and fluctuating characteristics of wind power mean that high-quality prediction intervals (PIs) production is a challenging problem. In this article, we propose a novel hybrid model for the WPIP based on the gated recurrent unit (GRU) neural networks and variational mode decomposition (VMD). In the hybrid model, VMD is employed to decompose complex wind power data into simplified modes. Basic GRU prediction models, comprising a GRU input layer, multiple fully connected layers, and a rank-ordered terminal layer, are then trained for each mode to produce PIs, which are combined to obtain final PIs. In addition, an adaptive optimization method based on constructed intervals (CIs) is proposed to build high-quality training labels for supervised learning with the hybrid model. Several numerical experiments were implemented to validate the effectiveness of the proposed method. The results indicate that the proposed method performs better than the traditional interval prediction models with much higher quality PIs, and it requires less training time.

COVID-19 in patients with rheumatic disease in Hubei province, China: a multicentre retrospective observational study.

Abstract: Summary Background In the ongoing COVID-19 pandemic, the susceptibility of patients with rheumatic diseases to COVID-19 remains unclear. We aimed to investigate susceptibility to COVID-19 in patients with autoimmune rheumatic diseases during the ongoing COVID-19 pandemic. Methods We did a multicentre retrospective study of patients with autoimmune rheumatic diseases in Hubei province, the epicentre of the COVID-19 outbreak in China. Patients with rheumatic diseases were contacted through an automated telephone-based survey to investigate their susceptibility to COVID-19. Data about COVID-19 exposure or diagnosis were collected. Families with a documented history of COVID-19 exposure, as defined by having at least one family member diagnosed with COVID-19, were followed up by medical professionals to obtain detailed information, including sex, age, smoking history, past medical history, use of medications, and information related to COVID-19. Findings Between March 20 and March 30, 2020, 6228 patients with autoimmune rheumatic diseases were included in the study. The overall rate of COVID-19 in patients with an autoimmune rheumatic disease in our study population was 0·43% (27 of 6228 patients). We identified 42 families in which COVID-19 was diagnosed between Dec 20, 2019, and March 20, 2020, in either patients with a rheumatic disease or in a family member residing at the same physical address during the outbreak. Within these 42 families, COVID-19 was diagnosed in 27 (63%) of 43 patients with a rheumatic disease and in 28 (34%) of 83 of their family members with no rheumatic disease (adjusted odds ratio [OR] 2·68 [95% CI 1·14–6·27]; p=0·023). Patients with rheumatic disease who were taking hydroxychloroquine had a lower risk of COVID-19 infection than patients taking other disease-modifying anti-rheumatic drugs (OR 0·09 [95% CI 0·01–0·94]; p=0·044). Additionally, the risk of COVID-19 was increased with age (adjusted OR 1·04 [95%CI 1·01–1·06]; p=0·0081). Interpretation Patients with autoimmune rheumatic disease might be more susceptible to COVID-19 infection than the general population. Funding National Natural Science Foundation of China and the Tongji Hospital Clinical Research Flagship Program.

Interfacial Oxygen Vacancy Engineered Two-Dimensional g-C3N4/BiOCl Heterostructures with Boosted Photocatalytic Conversion of CO2

Abstract: The CO2 conversion by photocatalysis has been a focus of global concern as yet and the exploring of efficient heterostructures is critical to promote the photocatalytic performance. However, the we...

Chemoprophylaxis, diagnosis, treatments, and discharge management of COVID-19: An evidence-based clinical practice guideline (updated version)

Abstract: The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of a rapidly spreading illness, coronavirus disease 2019 (COVID-19), affecting more than seventeen million people around the world. Diagnosis and treatment guidelines for clinicians caring for patients are needed. In the early stage, we have issued “A rapid advice guideline for the diagnosis and treatment of 2019 novel coronavirus (2019-nCoV) infected pneumonia (standard version)”; now there are many direct evidences emerged and may change some of previous recommendations and it is ripe for develop an evidence-based guideline. We formed a working group of clinical experts and methodologists. The steering group members proposed 29 questions that are relevant to the management of COVID-19 covering the following areas: chemoprophylaxis, diagnosis, treatments, and discharge management. We searched the literature for direct evidence on the management of COVID-19, and assessed its certainty generated recommendations using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. Recommendations were either strong or weak, or in the form of ungraded consensus-based statement. Finally, we issued 34 statements. Among them, 6 were strong recommendations for, 14 were weak recommendations for, 3 were weak recommendations against and 11 were ungraded consensus-based statement. They covered topics of chemoprophylaxis (including agents and Traditional Chinese Medicine (TCM) agents), diagnosis (including clinical manifestations, reverse transcription-polymerase chain reaction (RT-PCR), respiratory tract specimens, IgM and IgG antibody tests, chest computed tomography, chest x-ray, and CT features of asymptomatic infections), treatments (including lopinavir-ritonavir, umifenovir, favipiravir, interferon, remdesivir, combination of antiviral drugs, hydroxychloroquine/chloroquine, interleukin-6 inhibitors, interleukin-1 inhibitors, glucocorticoid, qingfei paidu decoction, lianhua qingwen granules/capsules, convalescent plasma, lung transplantation, invasive or noninvasive ventilation, and extracorporeal membrane oxygenation (ECMO)), and discharge management (including discharge criteria and management plan in patients whose RT-PCR retesting shows SARS-CoV-2 positive after discharge). We also created two figures of these recommendations for the implementation purpose. We hope these recommendations can help support healthcare workers caring for COVID-19 patients.

Attack-Resilient Event-Triggered Controller Design of DC Microgrids Under DoS Attacks

Abstract: This paper is concerned with the attack-resilient event-triggered controller design problem of a DC microgrid with multiple nonlinear constant power loads and intermittent denial-of-service (DoS) attacks. First, for a resource efficiency purpose, an event-triggering communication scheme is delicately devised in such a way to only invoke the data transmission over the communication line when the DoS attack is inactive. Second, via characterizing the DoS active and inactive time intervals, a new switching piecewise system model for the nonlinear DC microgrid system is presented. Third, a numerically efficient design criterion on the existence of the desired attack-resilient event-triggered controller is established. It is further shown that various performance indices including resource efficiency, attack resilience, robustness against disturbance, sampling performance of the DC microgrid system can be evaluated in a unified framework. Finally, an illustrative example is given to verify the effectiveness of the proposed control design method for the DC microgrid.

Fault Diagnosis for Rolling Bearings Based on Composite Multiscale Fine-Sorted Dispersion Entropy and SVM With Hybrid Mutation SCA-HHO Algorithm Optimization

Abstract: The health condition of rolling bearing possesses a significant impact on the safety and efficiency of rotating machinery. Accordingly, to diagnose the faults in rolling bearings effectively and accurately, a novel hybrid approach coupling variational mode decomposition (VMD), composite multiscale fine-sorted dispersion entropy (CMFSDE) and support vector machine (SVM) optimized by mutation sine cosine algorithm and Harris hawks optimization (MSCAHHO) is proposed in the paper. Firstly, VMD is employed to decompose raw vibration signals with various fault types into different sets of intrinsic mode functions (IMFs) to weaken the non-stationarity of signals, before which the parameter $K$ of VMD is decided through central frequency observation method. Subsequently, CMFSDE is put forward in this paper to analyze the complexity of fault signals by fully considering the relationship between neighboring elements based on composite multiscale technique, with which the representative features of different fault samples are extracted to construct feature vectors. Later, an enhanced hybrid optimization approach called MSCAHHO is proposed by integrating sine cosine algorithm (SCA) and a periodic mutation strategy to improve Harris hawks optimization (HHO). Then, MSCAHHO is employed to optimize the parameters of SVM, after which the optimal SVM model is utilized for fault classification. Finally, the performance of the proposed methodology is evaluated with four validity indices through comparative experiments. The experimental results reveal that the proposed VMD-CMFSDE-MSCAHHO-SVM method achieves favorable diagnosis results comparing with other relevant methods.

DRAIM: A Novel Delay-Constraint and Reverse Auction-Based Incentive Mechanism for WiFi Offloading

Abstract: Offloading cellular traffic through WiFi Access Points (APs) has been a promising way to relieve the overload of cellular networks. However, data offloading process consumes a lot of resources (e.g., energy, bandwidth, etc.). Given that the owners of APs are rational and selfish, they will not participate in the data offloading process without receiving the proper reward. Hence, there is an urgent need to develop an effective incentive mechanism to stimulate APs to take part in the data offloading process. This paper proposes a novel Delay-constraint and Reverse Auction-based Incentive Mechanism, named DRAIM. In DRAIM, we model the reverse auction-based incentive problem as a nonlinear integer problem from the business perspective, aiming to maximize the revenue of the Mobile Network Operator (MNO), and jointly consider the delay constraint of different applications in the optimization problem. Then, two low-complexity methods: Greedy Winner Selection Method (GWSM), and Dynamic Programming Winner Selection Method (DPWSM) are proposed to solve the optimization problem. Furthermore, an innovative standard Vickrey-Clarke-Groves scheme-based payment rule is proposed to guarantee the individual rationality and truthfulness properties of DPWSM. At last, extensive simulation results show that the proposed DPWSM is superior to the proposed GWSM and the Random Winner Selection Method in terms of the MNO’s utility and traffic load under different scenarios.

A3Y2Ge3O12 (A = Ca, Mg): Two novel microwave dielectric ceramics with contrasting τf and Q × f

Abstract: Two garnet-structured microwave dielectric ceramics of A3Y2Ge3O12 (A = Ca, Mg; called CYG and MYG, respectively) were synthesized. CYG was crystallized in a normal cubic garnet structure with Ca2+ fully occupying the dodecahedral (A) site, whereas MYG was an inverse garnet with mixed distribution of Mg2+/Y3+ at the A site. The difference in ionic occupation resulted in anomalies in microwave dielectric properties, with dielectric constant (er) = 14.1, quality factor (Q × f) = 12,600 GHz and positive temperature coefficient of resonant frequency (τf) =120.5 ppm/°C for MYG ceramic and er = 10.8, Q × f = 97,126 GHz and τf = −40.6 ppm/°C for CYG ceramic. The large deviations in measured er from theoretical eth possibly resulted from the garnet structural constraints leading to ‘rattling’ Mg2+ and Y3+ in A site of MYG. Infrared reflectivity spectra analysis revealed ion polarization contributed mostly to the permittivity of both ceramics in microwave frequency ranges.

Design, synthesis, and application of metal sulfides for Li–S batteries: progress and prospects

Abstract: Lithium–sulfur batteries have low material costs and high energy densities, which have attracted considerable research interest for application in next-generation energy-storage systems. However, the practical applications of Li–S batteries face challenges owing to their poor sulfur utilization, service lifetimes, and rate capability. Recently, great progress has been made in the design, synthesis, and application of micro/nanostructured metal sulfides to address obstacles facing Li–S batteries. This review aims to highlight valuable concepts from the latest reports. Major approaches to improve sulfur cathodes and strategies for preparing metal sulfide-based materials are first summarized with a particular focus on their main functions and useful properties. Then, the electrochemical activities of metal sulfides are classified and their applications in Li–S batteries are introduced to provide a fundamental understanding of the material interactions involved. In parallel, advancements in the use of interlayers, modification of separators, and protection of lithium anodes that involve metal sulfides are surveyed. Finally, special attention is paid to the general design principles, future prospects, and challenges facing metal sulfides for high-energy-density Li–S batteries.

COVID-19 in persons with chronic myeloid leukaemia.

Abstract: We studied by questionnaire 530 subjects with chronic myeloid leukaemia (CML) in Hubei Province during the recent SARS-CoV-2 epidemic. Five developed confirmed (N = 4) or probable COVID-19 (N = 1). Prevalence of COVID-19 in our subjects, 0.9% (95% Confidence Interval, 0.1, 1.8%) was ninefold higher than 0.1% (0, 0.12%) reported in normals but lower than 10% (6, 17%) reported in hospitalised persons with other haematological cancers or normal health-care providers, 7% (4, 12%). Co-variates associated with an increased risk of developing COVID-19 amongst persons with CML were exposure to someone infected with SARS-CoV-2 (P = 0.037), no complete haematologic response (P = 0.003) and co-morbidity(ies) (P = 0.024). There was also an increased risk of developing COVID-19 in subjects in advanced phase CML (P = 0.004) even when they achieved a complete cytogenetic response or major molecular response at the time of exposure to SARS-CoV-2. 1 of 21 subjects receiving 3rd generation tyrosine kinase-inhibitor (TKI) developed COVID-19 versus 3 of 346 subjects receiving imatinib versus 0 of 162 subjects receiving 2nd generation TKIs (P = 0.096). Other co-variates such as age and TKI-therapy duration were not significantly associated with an increased risk of developing COVID-19. Persons with these risk factors may benefit from increased surveillance of SARS-CoV-2 infection and possible protective isolation.

There may be virus in conjunctival secretion of patients with COVID-19.

Abstract: The COVID-19 is a public health emergency. The COVID-19 patient is the main source of infection, and asymptomatic infective patient can also be a source of infection (Bhadelia 2020). The main route of transmission is through respiratory droplets and contact (Burki 2020). It is not clear whether the 2019nCoV is transmitted through the mucous membrane of the eye. S-protein of SARS-like coronavirus can interact with human ACE2 protein and infect human respiratory epithelial cells (Ge et al. 2013). The human cornea and conjunctiva express ACE2 receptor, which can theoretically bind to the 2019-nCoV and cause infection. Our hospital is from the epidemic area. In our hospital, 37 patients of 2019nCoV infection pneumonia were detected the nucleic acid in the conjunctival sac by real-time RT-PCR. According the Chinese COVID-19 diagnosis and treatment (V) (Huang et al. 2020), 12 cases were severe patients, and the others were mild patients. Three cases had conjunctival congestion and other inflammatory appearance. One case of severe patients, which conjunctival sac secretion nucleic acid test was positive by real-time RT-PCR, but this severe patient had no conjunctivitis. The other 36 patients were negative in nucleic acid test of conjunctival secretion. Therefore, we must pay attention to the possibility of virus in conjunctival sac secretion of COVID-19 patients and need to further detect the virus in conjunctival sac secretion as evidence. The viral load of conjunctival sac secretion of COVID-19 patients is relatively low, and we estimate the viral load is directly proportional to the severity of the disease. Whether the 2019-nCoV can be transmitted through conjunctiva is further studied. References

A child confirmed COVID-19 with only symptoms of conjunctivitis and eyelid dermatitis.

Abstract: Dear Editor, As we all know, the 2019 novel coronavirus disease (COVID-19) infected by SARS-CoV-2 are spreading worldwide. It was reported that there were different clinical features between pediatric and adult patients with COVID-19 [1]. Our previous study had shown that conjunctivitis symptoms were found in a minority of adult patients confirmed COVID-19, with positive results of viral nucleic acid in conjunctival swab samples [2]. Nevertheless, there are no reports in the medical literature at this time, to our knowledge, on children infected by SARS-CoV-2 with ocular abnormalities. Here we firstly report an infected boy characterized by conjunctivitis and eyelid dermatitis without any other symptom. The child, 2 years and 10 months old, was detected and confirmed through community screening with positive result of SARS-Cov-2 nucleic acid in his nasopharyngeal swabs on February 17, 2020. He likely acquired SARS-CoV-2 infection from his household member because of his father and grandma diagnosed before. He was quarantined at a government designated hotel with his mother, for being asymptomatic initially. On day 7 of confinement, the child presented with conjunctivitis and eyelid dermatitis (Fig. 1), and was referred to our hospital subsequently. Admission tests reconfirmed the SARSCoV-2 infection by RT-PCR, meanwhile revealed myocardial damage and atypical change in lymphocyte count (Table 1), with normal chest CT. After treatment depending on the national protocol in China [3], conjunctivitis and eyelid dermatitis gradually disappeared 5 days later. From days 10 to 12 of admission, negative results of viral nucleic acid twice in 48 h, with positive IgG but negative IgM of the virus in serum, indicated that the virus had been cleared [4]. The child left hospital on March 7, 2020, with no respiratory and other systemic symptoms until now. Our child was found muscle enzyme elevation unintentionally; meanwhile, the trend of recovery was not clear when leaving hospital (Table 1). It indicated that we should closely track the blood indexes of child patients as soon as earlier to know the condition of myocardium and whole system after diagnosed even though without any clinical manifestation. Lymphocyte count usually decreased in the early stage of most adult cases [5], while that of this child was slightly higher than normal in admission tests. To some extent, it was related to that the count and proportion of lymphocytes in children under 5 years old are higher than those in adults in the general populat ion. Therefore, the significance of this test for early diagnosis of COVID-19 should be combined with age and need to be confirmed by large sample data. Studies had shown that ACE2 is a receptor of SARSCoV-2 to invasion [6]. ACE2 is expressed not only in human type II alveolar epithelial cells, but also in cornea and conjunctiva [7], suggesting that ocular surface tissue may also be a potential target tissue infected by SARS-CoV-2. Our previous report had shown that conjunctivitis symptoms were found in a small number of adult patients confirmed COVID-19 [2]. However, so far, there has been no report on infected children with eye symptoms. This case showed a child involved conjunctivitis and eyelid dermatitis on day 7 of COVID-19 confirmed. It may be caused by virus infection, or by secondary bacterial infection with poor body resistance after systemic virus infection. * Liang Liang liangliang419519@ctgu.edu.cn

Soil erosion potential hotspot zone identification using machine learning and statistical approaches in eastern India

Abstract: Land degradation is very severe in the subtropical monsoon-dominated region due to the uncertainty of rainfall in the long term, and most of the rainfall occurs with high intensity and kinetic energy over short time periods. So, keeping this scenario in view, the main objective of this work is to identify areas vulnerable to soil erosion and propose the most suitable model for soil erosion susceptibility in subtropical environment. The implementation of machine learning and artificial intelligence techniques with a GIS environment for determining erosion susceptibility is highly acceptable in terms of optimal accuracy. The point-specific values of different elements from random sampling were considered for this study. Sensitivity analysis of the predicted models (i.e., analytical neural network, geographically weighted regression and GWR–ANN ensemble) was performed using the maximum causative factors and related primary field observations. The area under curve of receiver operating system reveals precision with 87.13, 89.57 and 91.64 for GWR, ANN and ensemble GWR–ANN, respectively. The ensemble GWR–ANN is more optimal than the GWR, ANN for determining water-induced soil erosion susceptibility. The process of soil erosion is not a unidirectional process, so the multidimensional impacts from the conditioning factors have to be determined precisely by considering the maximum possible factors as well as selecting optimal models for specific regions.