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Digital contact tracing has been recently advocated by China and many countries as part of digital prevention measures on COVID-19. Controversies have been raised about their effectiveness in practice as it remains open how they can be fully utilized to control COVID-19. In this article, we show that an abundance of information can be extracted from digital contact tracing for COVID-19 prevention and control. Specifically, we construct a temporal contact graph that quantifies the daily contacts between infectious and susceptible individuals by exploiting a large volume of location-related data contributed by 10,527,737 smartphone users in Wuhan, China. The temporal contact graph reveals five time-varying indicators can accurately capture actual contact trends at population level, demonstrating that travel restrictions (e.g., city lockdown) in Wuhan played an important role in containing COVID-19. We reveal a strong correlation between the contacts level and the epidemic size, and estimate several significant epidemiological parameters (e.g., serial interval). We also show that user participation rate exerts higher influence on situation evaluation than user upload rate does, indicating a sub-sampled dataset would be as good at prediction. At individual level, however, the temporal contact graph plays a limited role, since the behavior distinction between the infected and uninfected individuals are not substantial. The revealed results can tell the effectiveness of digital contact tracing against COVID-19, providing guidelines for governments to implement interventions using information technology. Contact tracing using mobile phones has been a strategy used by many countries to limit the spread of COVID-19. Here, the authors use location-related phone data from Wuhan to construct a temporal contact graph and demonstrate a strong correlation between contacts level and epidemic size, thus justifying the effectiveness of the approach. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to explore the potential impact of maternal gestational weight gain (GWG), infant birth weight, and postnatal weight change (ΔWAZ) on the relationship between maternal prepregnancy BMI (ppBMI) and childhood BMI.Methods: This retrospective cohort study analyzed a data set from Wuhan, China. The mediation effect of targeted mediators on the association between maternal BMI and childhood BMI at the age of 2 years was analyzed.Results: In the mediation model comprising maternal GWG, infant birth weight, and the first-6-month ΔWAZ as mediators of the association between ppBMI and children's BMI, the per unit increase in ppBMI resulted in a 0.01-kg/m2 increase in children's BMI, through all three mediators. For the model comprising infant birth weight and the first-6-month ΔWAZ as mediators but maternal GWG as a moderator, the indirect effects of the first-6-month ΔWAZ on the relationship between ppBMI and childhood BMI was 0.0018 higher when maternal GWG increased from average values to 1 SD above the average values.Conclusions: Maternal GWG, infant birth weight, and the first-6-month ΔWAZ mediated the effects of maternal ppBMI on children's BMI. Interventions targeting these factors can mitigate the risk of childhood obesity. [ABSTRACT FROM AUTHOR]

Purpose: To summarize the clinical features and effective therapy of severe COVID-19 patients. Patients and Methods: In this retrospective, multicenter study, the medical records of COVID-19 patients in Hunan, from January 21, 2020 to February 19, 2020 were reviewed. Results: Of the 350 COVID-19 patients, 13.7% were severe cases. On admission, compared with non-severe patients, more severe patients had a neutrophil/lymphocyte ratio > 3 (58.3% vs 33.8%, P=0.001), D-dimer > 1 mg/L (41.7% vs 13.6%, P< 0.0001), higher level of CRP (39.1 mg/L, IQR18.1– 75.9 vs 13.4 mg/L, IQR5.0– 32.8, P< 0.0001), and multiple pneumonia on CT (77.1% vs 18.2%, P< 0.0001). All severe patients received oxygen support. 95.8% of them received antivirals, and the most frequent therapy was lopinavir and ritonavir plus human interferon-α 2b. Moxifloxacin was used in 70.8% severe patients. The total dosage of methylprednisolone sodium succinate was 640 mg (IQR 360– 960) in severe patients, and the duration of use was 8.5 days (IQR 6.8– 11.3). The total dosage of immunoglobulin was 80 g (IQR, 60– 140) in severe patients, and the duration was 8.0 days (IQR, 6.0– 11.5). As of March 15, 2020, 95.8% of the severe patients had been discharged and only two deaths occurred. Conclusion: The rate of severe cases and mortality of COVID-19 in Hunan are lower than those in Wuhan. In addition to antivirals and oxygen support, timely interventions including corticosteroids, immunoglobulin, and antibiotics, contribute to improving the prognosis of severe COVID-19 patients. [ABSTRACT FROM AUTHOR]

Potassium (K) fertilizer additions can result in high crop yields of good quality and low nitrogen (N) loss; however, the interaction between K and N fertilizer and its effect on N 2 O emissions and associated microbes remain unclear. We investigated this in a pot experiment with six fertilizer treatments involving K and two sources of N, using agricultural soil from the suburbs of Wuhan, central China. The aim was to determine the effects of the interaction between K and different forms of N on the N 2 O flux and the abundance of nitrifying and denitrifying microbial communities, using static chamber-gas chromatography and high-throughput sequencing methods. Compared with no fertilizer control (CK), the addition of nitrate fertilizer (NN) or ammonia fertilizer (AN) or K fertilizer significantly increased N 2 O emissions. However, the combined application (NNK) of K and NN significantly reduced the average N 2 O emissions by 28.3%, while the combined application (ANK) of K and AN increased N 2 O emissions by 22.7%. The abundance of nitrifying genes amoA in ammonia oxidizing archaea (AOA) and ammonia oxidizing bacteria (AOB) changed in response to N and/or K fertilization, but the denitrifying genes nar G, nir K and nor l were strongly correlated with N 2 O emissions. This suggests that N or K fertilizer and their interaction affect N 2 O emissions mainly by altering the abundance of functional genes of denitrifying microbes in the soil-plant system. The genera Paracoccus, Rubrivivax and Geobacter as well as Streptomyces and Hyphomicrobium play an important role in N 2 O emissions during denitrification with the combined application of N and K. • Potassium addition reduces nitrate-stimulations on soil N 2 O emissions. • NNK treatment lowers the abundance of nirK and norB and most denitrifiers than NN treatment. • Soils with lower N 2 O emissions have a lower norB/nosZ ratio. [ABSTRACT FROM AUTHOR]

Background: In December 2019, the novel coronavirus disease 2019 (COVID-19) emerged in Wuhan, Hubei Province, China. It rapidly spread and many cases were identified in multiple countries, posing a global health problem. Here, we report the first patient cured of COVID-19 infection in Changsha, China, and the symptoms, diagnosis, treatment, and management of this patient are all described in this report.Case Presentation: A 57-year-old woman developed cough and fever after returning to Changsha from Wuhan on January 9, 2020. She tested positive for COVID-19 infection, a diagnosis which was supported by chest CT. The patient was treated with lopinavir and ritonavir tablets and interferon alfa-2b injection. A low dose of glucocorticoids was used for a short period to control bilateral lung immune response, and this patient avoided being crushed by cytokine storms that might have occurred. The clinical condition of this patient improved, and a COVID-19 assay conducted on January 25, 2020 generated negative results. This patient recovered and was discharged on January 30, 2020.Conclusions: Currently, there are numerous reports on COVID-19 infections focusing on the disease's epidemiological and clinical characteristics. This case describes the symptoms, diagnosis, treatment, and management of a patient cured of COVID-19 infection, which may serve as reference for future cases, while further studies are needed. [ABSTRACT FROM AUTHOR]

Potassium (K) fertilizer plays an important role in increasing crop yield, quality, and nitrogen use efficiency. However, little is known about its environmental impacts, such as its effects on emissions of the greenhouse gas nitrous oxide (N 2 O). A nitrogen-15 (15N) tracer laboratory experiment was therefore performed in an acidic agricultural soil in the suburbs of Wuhan, central China, to determine the effects of K fertilizer on N 2 O emissions and nitrification/denitrification product ratios under N fertilization. During 15-d incubation periods with a fixed initial N concentration (80 mg kg−1), K application increased average N 2 O emission rates significantly (1.6–10.8-fold) compared to the control treatment. N 2 O emissions derived from nitrification and denitrification both increased in K-treated soil, and denitrification contributed more to the increase; its contribution ratio rose from 32% without K fertilizer to 53% with 300 mg kg−1 of K applied. The increase in N 2 O emissions under K fertilization is probably due to an increase in the activity of denitrifying microorganisms and acid-resistant nitrifying microorganisms caused by higher K+ concentrations and lower soil pH. Combined treatment with potassium chloride (KCl) and N fertilizer produced lower N 2 O emissions than combined treatment with potassium sulfate (K 2 SO 4) and N fertilizer during 15-d incubation periods. Our results imply that there are significant interaction effects between N fertilizers and K fertilizers on N 2 O emissions. In particular, combining N fertilizers with fertilizers that reduce soil acidity or contain Cl or K ions may significantly affect agricultural N 2 O emissions. Image 1 • K fertilizer application significantly increased N 2 O emissions in agricultural acid soil. • Denitrification was an important pathway of N 2 O production in agricultural acid soil. • Potassium fertilizer increased the contribution of denitrification to N 2 O emission. [ABSTRACT FROM AUTHOR]

Coronavirus disease 2019 (COVID-19) is profoundly affecting lives around the globe. Previous studies on COVID-19 mainly focused on epidemiological, clinical, and radiological features of patients with confirmed infection. Little attention has been paid to the follow-up of recovered patients. As a vulnerable population to adverse events, the health status of the COVID-19 recovered pediatric patients is of great concern. We aimed to investigate the prevalence of behavioral problems among pediatric patients recovered from the COVID-19 in Wuhan, China. A total of 122 children who were suspected or confirmed COVID-19 cases and hospitalized for treatment were enrolled in the study between April 2020 and May 2020 in Wuhan, China. We collected related information about hospitalization and discharge of the children and emotional symptoms of their parents through electronic medical records and questionnaire. The behavioral problems of children were examined by applying the parent-reported the Strengths and Difficulties Questionnaire (SDQ). The participant children were discharged from hospital after about two months. Among them, 76 (62%) were boys, and the mean age was 6.71 years old. The highest prevalence of behavioral problems among pediatric children with COVID-19 was for prosocial behavior (15%), followed by total difficulties (13%), emotional symptoms (11%), hyperactivity (10%), conduct problems (9%), and peer problems (1%). With regarding to their parents, 26% reported having symptoms of anxiety and 23% as having symptoms of depression. The scores of SDQ were higher in those children whose parents have emotional problems compared to parents without. Long-term follow up studies on the psychological and behavioral problems of COVID-19 recovered children and their parents are warranted. • About 15% recovered children infected with COVID-19 have prosocial behavior problems. • For parents of children infected with COVID-19, 26% had depression symptoms. • For parents of children infected with COVID-19, 23% had anxiety symptoms. • Children whose parents had emotional problems scored higher on behavioral problems. [ABSTRACT FROM AUTHOR]