Search

Though mesh generated by UAV-based oblique photogrammetry has revolutionized the large urban scene data representation, its semantic segmentation still challenging due to structural irregularities. In this paper, a deep learning model is proposed for the mesh semantic segmentation. To efficiently capture local geometry and neighbourhood context within the mesh, graph concept and transformer blocks are employed for mesh representation and feature learning. Based on these components, a hierarchical network architecture is presented. Experimental results demonstrate that the proposed network performs well on the self-made Wuhan dataset. The ablation study shows the improvement brought by each component in the network. By comparison, both mIoU and mF1 of our network are much higher than the prior work on the public SUM dataset, achieving 83.7% and 73.7%. [ABSTRACT FROM AUTHOR]

aiming Zhuo,1,3 Kai Yu,5 Tian Shen,4 Yifeng Xu,1,2 Zhen Wang1– 31Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China; 2Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China; 3Shanghai Psychological Medical Team Supporting Hubei, Shanghai, People's Republic of China; 4School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China; 5MoE Key Laboratory of Artificial Intelligence, AI Institute Shanghai Jiao Tong University, Shanghai, People's Republic of ChinaCorrespondence: Zhen Wang Email wangzhen@smhc.org.cnYifeng Xu Email xuyifeng@smhc.org.cn Background: Since the novel coronavirus disease (COVID-19) outbreak in Wuhan, thousands of medical workers have been dispatched to support Wuhan against the virus. The purpose of this study was to identify the independent risk factors for psychological distress in order to develop a more effective strategy and precise evidence-based psychological intervention for medical workers. Methods: This multisite cross-sectional survey recruited doctors and nurses from local and nonlocal medical teams working at 16 hospitals in Wuhan to complete this online survey from February to March, 2020. Psychological status was evaluated through Perceived Stress Scales (PSS), Patient Health Questionnaire-9 (PHQ-9), General Anxiety Disorder Scale (GAD-7) and Acute Stress Disorder Scale (ASDS). Results: Of 966 participants, the prevalence of stress (95.9%), depression (46.0%) and anxiety (39.3%) were high. Local medical workers exhibited even higher scores of PSS, PHQ-9, GAD-7 and ASDS than those from outside Hubei (P< 0.001). Females had more severe perceived stress, depression and anxiety than males (P< 0.001). Multiple logistic regression showed that perceived stress is associated with increased odds of depression (OR=1.413; 95% CI: 1.338– 1.493; P< 0.001) and anxiety (OR=1.515; 95% CI: 1.407– 1.631; P< 0.001). Conclusion: Our findings demonstrated a high prevalence of stress, depression, anxiety and acute distress among medical workers on the front-line during the COVID-19 outbreak in Wuhan. The level of psychological impact may be mediated by individual perceptions of stressful events. [ABSTRACT FROM AUTHOR]

Background: As of June 1, 2020, coronavirus disease 2019 (COVID-19) has caused more than 6,000,000 infected persons and 360,000 deaths globally. Previous studies revealed pregnant women with COVID-19 had similar clinical manifestations to nonpregnant women. However, little is known about the outcome of neonates born to infected women.Methods and Findings: In this retrospective study, we studied 29 pregnant women with COVID-19 infection delivered in 2 designated general hospitals in Wuhan, China between January 30 and March 10, 2020, and 30 neonates (1 set of twins). Maternal demographic characteristics, delivery course, symptoms, and laboratory tests from hospital records were extracted. Neonates were hospitalized if they had symptoms (5 cases) or their guardians agreed to a hospitalized quarantine (13 cases), whereas symptom-free neonates also could be discharged after birth and followed up through telephone (12 cases). For hospitalized neonates, laboratory test results and chest X-ray or computed tomography (CT) were extracted from hospital records. The presence of antibody of SARS-CoV-2 was assessed in the serum of 4 neonates. Among 29 pregnant COVID-19-infected women (13 confirmed and 16 clinical diagnosed), the majority had higher education (56.6%), half were employed (51.7%), and their mean age was 29 years. Fourteen women experienced mild symptoms including fever (8), cough (9), shortness of breath (3), diarrhea (2), vomiting (1), and 15 were symptom-free. Eleven of 29 women had pregnancy complications, and 27 elected to have a cesarean section delivery. Of 30 neonates, 18 were admitted to Wuhan Children's Hospital for quarantine and care, whereas the other 12 neonates discharged after birth without any symptoms and had normal follow-up. Five hospitalized neonates were diagnosed as COVID-19 infection (2 confirmed and 3 suspected). In addition, 12 of 13 other hospitalized neonates presented with radiological features for pneumonia through X-ray or CT screening, 1 with occasional cough and the others without associated symptoms. SARS-CoV-2 specific serum immunoglobulin M (IgM) and immunoglobulin G (IgG) were measured in 4 neonates and 2 were positive. The limited sample size limited statistical comparison between groups.Conclusions: In this study, we observed COVID-19 or radiological features of pneumonia in some, but not all, neonates born to women with COVID-19 infection. These findings suggest that intrauterine or intrapartum transmission is possible and warrants clinical caution and further investigation.Trial Registration: Chinese Clinical Trial Registry, ChiCTR2000031954 (Maternal and Perinatal Outcomes of Women with coronavirus disease 2019 (COVID-19): a multicenter retrospective cohort study). [ABSTRACT FROM AUTHOR]

Wuhan took strict measures to prevent the spread of COVID-19 from January 26 to April 7 in 2020. The lockdown reduced the concentrations of atmospheric pollutants, except ozone (O 3). To investigate the increase in O 3 during the lockdown, trace gas pollutants were collected. The initial concentrations of volatile organic compounds (VOCs) were calculated based on a photochemical ratio method, and the ozone formation potential (OFP) was obtained using the initial and measured VOC concentrations. The O 3 formation regime was NO X -limited based on the VOCs/NO X diurnal ratios during the lockdown period. The reduced nitric oxide (NO) concentrations and lower wind speed (WS) could explain the night-time O 3 accumulation. The initial total VOCs (TVOCs) during the lockdown were 47.6 ± 2.9 ppbv, and alkenes contributed 48.1%. The photochemical loss amounts of alkenes were an order of magnitude higher than those of alkenes in the same period in 2019 and increased from 16.6 to 28.0 ppbv in the daytime. The higher initial alkene concentrations sustained higher OFP during the lockdown, reaching between 252.4 and 504.4 ppbv. The initial isoprene contributed approximately 35.0–55.0% to the total OFP and had a positive correlation with the increasing O 3 concentrations. Approximately 75.5% of the temperatures were concentrated in the range of 5 and 20 °C, which were higher than those in 2019. In addition to stronger solar radiation, the higher temperatures induced higher isoprene emission rates, partially accounting for the higher isoprene concentrations. Lower isoprene-emitting trees should be considered for future urban vegetation to control O 3 episodes. [Display omitted] • The ozone formation regime during the lockdown in Wuhan was NO X -limited. • Alkenes contributed 48.1% to the initial total VOC concentrations during the day. • Initial isoprene contributed 35%–55% to the ozone formation potential (OFP). • OFP derived from initial isoprene was positively correlated with ozone concentrations. • Higher air temperatures lead to increased emissions of isoprene. [ABSTRACT FROM AUTHOR]

• Introduces an evaluation method of solar energy potential for industrial block. • Single-storey industrial blocks have the largest total solar potential. • Density has a significant impact on solar potential for industrial blocks. • Roof has the highest effective installation rate, then South and West facade. Industrial blocks are an important part of the city which is very suitable for PV application because of its large-scale, unified property rights and simple form. In this study, a multi-dimensional evaluation method of solar energy potential suitable for the block-scale is constructed. Then, 48 cases of industrial blocks in a typical city of china were selected as examples. Basing on morphological parameters, all cases were classified into 7 types by clustering algorithm. Afterwards, the total amount and distribution of the solar energy potential were calculated. Finally, the strategies of the photovoltaic system application in blocks were proposed according to types of blocks. It is found that there is significant difference in solar energy potential between different types of industrial blocks. Among them, solar energy potential of single-storey types is the highest up to 90.85 kW h/m2•year, while solar energy potential of high-rise type blocks is relatively lower which is only 55.64 kW h/m2•year. In addition, block shape has obvious impact on solar energy potential, among which building density having the greatest influence, as building density increases from 20 % to 55 %, the solar energy potential also increased by 138.74 % from 42.54 kW h/m2•year to 101.56 kW h/m2•year. [ABSTRACT FROM AUTHOR]

• New method for evaluating rooftop PV potential in land-use type. • Decline the difficulty of obtaining urban land-use data. • Capability of analyzing several cities with less time cost. • Three types of land use have the highest rooftop solar utilization potential. To strengthen the synergy between urban photovoltaic development and urban planning, which can help to promote photovoltaic and renewable energy development in cities, a workflow based on a deep-learning method by using neural networks and urban satellite images is constructed, which is applied to study the relationship between urban rooftop photovoltaic potential and urban land use. A Chinese city, Wuhan, has been considered the subject and divided into 5184 units, which is a 1201.2 km2 area in central urban space. The result shows that, three types of urban land use type have the highest rooftop photovoltaic potential, which are Continuous Urban area, Discontinuous Dense Urban area and Industrial, commercial, public and education unit. The annual photovoltaic potential of these three land use types have reached 1818.41 GWh/year, 1957.32 GWh/year and 2022.71 GWh/year, and the average photovoltaic power generation per unit area of these three types have reached 11.23 GWh/km2·year, 9.99 GWh/km2·year and 13.07 GWh/km2·year. In addition, these three land use types contributed 71.4% of the city's total rooftop photovoltaic potential. When considering the coordination of roof photovoltaic development and urban planning, these three types of land use should be given priority. The method and findings can provide urban planning authorities with tools and data to reference when developing urban master plan and PV development plans. [ABSTRACT FROM AUTHOR]

• An urban block classification method based on clustering algorithm is applied. • Occlusion coefficient shows three main groups, which represent three types of urban block. • Occlusion factors of urban block types helps to revise the evaluation of urban roof solar energy potential. • A method for quickly obtaining solar energy potential based on 2D urban roof images is introduced. • Correlation between coefficient and latitude of cities has been discussed, which shows high relevance and can help to assess other cities. Relevant research shows that the potential of solar energy utilization varies greatly in different occlusion conditions. However, existing methods of assessing macro-city-scale solar roof utilization potential are not capable of considering the factor of mutual occlusion between urban buildings. To measure the overall solar photovoltaic utilization potential of the city, it is necessary to quantify the occlusion caused by the urban environmental building roof. This paper uses typical high-density blocks to quantify differences of occlusions on the building roof caused by urban blocks and building functions. Taking Wuhan as an example, a large number of urban blocks which form indicators were counted were selected as research samples, the data sets covers six types of morphological indicators to classify the urban blocks, and then the above blocks was modelled to simulate the solar radiation in order to obtain the values and combine with their morphological parameters, which will help to get roof solar occlusion factors by linear regression ways. The overall roof occlusion coefficient result of Wuhan is 0.079. By applying the above-mentioned occlusion coefficient to measure the solar energy potential of Hongshan District in Wuhan, the annual photovoltaic power generation was calculated to be able to reach 168.02GWh. [ABSTRACT FROM AUTHOR]

• Characteristics of PM 2.5 components, VOCs during the haze and dust period were investigated. • SOC were estimated by EC tracer method. • SOA formation were enhanced during dust episode. • Photochemical reactions were responsible for the enhanced SOA formation. To investigate the effect of frequently occurring mineral dust on the formation of secondary organic aerosol (SOA), 106 volatile organic compounds (VOCs), trace gas pollutants and chemical components of PM 2.5 were measured continuously in January 2021 in Wuhan, Central China. The observation period was divided into two stages that included a haze period and a following dust period, based on the ratio of PM 2.5 and PM 10 concentrations. The average ratio of secondary organic carbon (SOC) to elemental carbon (EC) was 1.98 during the dust period, which was higher than that during the haze period (0.69). The contribution of SOA to PM 2.5 also increased from 2.75% to 8.64%. The analysis of the relationships between the SOA and relative humidity (RH) and the odd oxygen (e.g., O X = O 3 + NO 2) levels suggested that photochemical reactions played a more important role in the enhancement of SOA production during the dust period than the aqueous-phase reactions. The heterogeneous photochemical production of OH radicals in the presence of metal oxides during the dust period was believed to be enhanced. Meanwhile, the ratios of trans-2-butene to cis-2-butene and m-/p-xylene to ethylbenzene (X/E) dropped significantly, confirming that stronger photochemical reactions occurred and SOA precursors formed efficiently. These results verified the laboratory findings that metal oxides in mineral dust could catalyse the oxidation of VOCs and induce higher SOA production. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: The outbreak of Coronavirus Disease 2019 (COVID-19) has been raising global anxiety and fear to the real or perceived health threat from the virus. This study aimed to investigate the psychological impacts and depression in the front-line non-medical workers in Wuhan, the first and the worst hit place by COVID-19.Methods: A total of 191 front-line non-medical workers in Wuhan were recruited by online survey. The Positive and Negative Affect Schedule (PANAS), the Stress Reaction Questionnaire (SRQ) and the Patient Health Questionnaire-9 (PHQ) were used.Results: The results showed that 50.3% (96) participants reported the clinically significant symptoms of depression. Among them, 33.0% (63) participants were with mild depression, 10.5% (20) participants with moderate depression, 5.8% (11) with moderately severe depression, and 1.0% (2) with severe depression. Participants with depression tend to be post-90 s (the generation born after 1990s), females, with increased levels of stress reactions, increased negative affects, but lower positive affects compared to these without depression. The stepwise logistic regression analysis revealed that post-90 s (β = 0.908, P = 0.016), the emotional reaction (β = 0.122, P = 0.005) and physical reaction (β = 0.124, P = 0.020) in SQR were significant independent responsible for the development of depression.Conclusion: The findings of the present study suggest the targeted psychological intervention measures should be developed to improve the mental health of non-medical workers on the front-line of COVID-19 epidemic, especially the females and younger individuals. [ABSTRACT FROM AUTHOR]

In this study, comprehensive field observations were collected out in urban, suburban and industrial areas of Wuhan, China in winter to compare and analyse the concentration level, source and secondary transformation potential of volatile organic compounds (VOCs). And the CJZ, SLDD and HGQ sites were used to assess the atmospheric VOC pollution in urban, suburban and industrial areas respectively. The total VOC (TVOC) concentrations at the three sites were 25.35 ± 12.66, 28.55 ± 9.19 and 66.81 ± 65.40 ppb, respectively, which shows that pollution in the industrial area is more serious. Vehicle exhaust and industrial emissions are the main sources of VOC emissions in Wuhan. The contributions of vehicle exhaust and industrial emissions to the VOCs are 57.03%, 48.44% and 55.18% at the CJZ, SLDD and HGQ sites, respectively. High potential source contribution function values mainly occur in the east and southwest areas of the sampling sites, indicating that Wuhan has a strong local VOC source. In addition, alkenes and aromatics play a leading role in secondary conversion during selected periods of relatively high O 3 concentration. At the same time, the simulation results of the F0AM model fall within the VOC-limited regimes, and the suburban and industrial area are more sensitive to VOCs. The O 3 concentration can be effectively reduced when the reduction ratio of AVOCs/NOx is 1.25–1.56, 1.11–1.20 and 1.42–1.61. In general, it is imperative to reduce VOC emissions by region and implement active VOC-species-focused strategies. [Display omitted] • The TVOC concentration in the industrial area was 2–3 times higher than that in the urban and suburban areas. • Different functional areas had distinct chemical features in atmosphere. • Emissions from industrial areas had a significant transmission impact on urban areas. • Alkenes and aromatics played a dominant role in secondary transformation. • Industrial areas had a higher reduction ratio of AVOCs/NOx. [ABSTRACT FROM AUTHOR]