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The COVID-19 pandemic has had a profound impact on the aviation sector. Correspondingly, Extensive research has explored various perspectives on the effects of the pandemic on the aviation sector. With the pandemic gradually coming to an end, it is important to conduct a detailed review of the literature and analyze past events carefully. This paper presents a systematic review of the literature on the impact of COVID-19 on air passenger travel at different stages. It identifies potential direct effects and indirect effects of the COVID-19 pandemic. It also investigates the two stages of the pandemic-aviation relationship, providing insights into how the relationship has evolved over time. Additionally, the research summarises key findings on the effects of COVID-19 on air travel demand and supply. These findings encompass various aspects, including travel demand, airport operations, airline operations, and network operations. The paper concludes by suggesting that ongoing analysis of the pandemic's effects can inform future policies and measures that can help the aviation industry recover and thrive. [ABSTRACT FROM AUTHOR]

ObjectiveTo compare and evaluate the improvement degree of spermatogenic dysfunction mice at different recovery periods after cyclophosphamide modeling.MethodsForty-eight male ICR mice aged 4-5 weeks with the body weight of approximately 18-20 g were randomly divided into three control groups and three model groups, with 8 mice in each group. Each mouse of three model groups was intraperitoneally injected with 60 mg/kg cyclophosphamide continuously from the 1st to 7th day of the experiment, while each mouse of three control groups was intraperitoneally injected with the corresponding volume of normal saline. Then these mice were continued to be fed for another 7, 14 and 21 days after cyclophosphamide injection, respectively. A corresponding control group was set for each model group. The mice in each group were sacrificed after blood collection through orbital veins at corresponding time points. Testis, epididymis and seminal vesicle were taken and weighed, and their reproductive organ indexes were calculated. Histopathological changes of testis and epididymis were compared after HE staining.Sperm quality analysis was used to determine sperm-related indexes. Serum reproductive hormone content, testicular oxidative stress level and testicular signature enzyme activity were detected by ELISA and related kits.Results Compared with the control group, on the 7th, 14th and 21st day after cyclophosphamide treatment, the testicular index of mice in the model group decreased significantly (P

Objective To compare and evaluate the improvement degree of spermatogenic dysfunction mice at different recovery periods after cyclophosphamide modeling. Methods Forty-eight male ICR mice aged 4-5 weeks with the body weight of approximately 18-20 g were randomly divided into three control groups and three model groups, with 8 mice in each group. Each mouse of three model groups was intraperitoneally injected with 60 mg/kg cyclophosphamide continuously from the 1st to 7th day of the experiment, while each mouse of three control groups was intraperitoneally injected with the corresponding volume of normal saline. Then these mice were continued to be fed for another 7, 14 and 21 days after cyclophosphamide injection, respectively. A corresponding control group was set for each model group. The mice in each group were sacrificed after blood collection through orbital veins at corresponding time points. Testis, epididymis and seminal vesicle were taken and weighed, and their reproductive organ indexes were calculated. Histopathological changes of testis and epididymis were compared after HE staining.Sperm quality analysis was used to determine sperm-related indexes. Serum reproductive hormone content, testicular oxidative stress level and testicular signature enzyme activity were detected by ELISA and related kits.Results Compared with the control group, on the 7th, 14th and 21st day after cyclophosphamide treatment, the testicular index of mice in the model group decreased significantly (P<0.01). The epididymis index decreased significantly on the 7th and 14th day, and the seminal vesicle index decreased obviously on the 7th and 21st day (P<0.05). And the histopathological damage of testis and epididymis of the model group gradually alleviated over time. On the 7th and 14th day after cyclophosphamide treatment, the sperm count of the model group declined remarkably (P<0.01), the serum testosterone (T) level reduced (P<0.05), the malonaldehyde (MDA) content of testis increased significantly (P<0.01), the content of reduced glutathione (GSH) and superoxide dismutase (SOD) decreased obviously (P<0.05),the lactic dehydrogenase (LDH) activity of testis reduced obviously (P<0.05), the gamma-glutamyl transpeptidase (γ-GT) activity increased significantly (P<0.05), the latter two of which are important testicular signature enzymes. Therein on the 7th day after cyclophosphamide treatment, the sperm motility decreased significantly (P<0.001), the rate of sperm malformation increased obviously (P<0.05), the serum levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) increased notably (P<0.01). Nevertheless on the 21st day after cyclophosphamide treatment, the sperm-related indexes, the content of serum reproductive hormone, the level of testicular oxidative stress and the activity of testicular signature enzyme did not change significantly (P＞0.05). Conclusion The reproductive toxicity in mice was more apparent on the 7th day after intraperitoneal injection with 60 mg/kg cyclophosphamide for seven days, at which time the more desirable spermatogenic dysfunction model of mice could be established. However, with the prolongation of the recovery period, the indexes of spermatogenic dysfunction in mice gradually recovered and approached the normal level on the 21st day after cyclophosphamide treatment. [ABSTRACT FROM AUTHOR]

This study was designed to determine the best intervention time (acute, subacute, and chronic stages) for Walkbot robot-assisted gait training (RAGT) rehabilitation to improve clinical outcomes, including sensorimotor function, balance, cognition, and activities of daily living, in hemiparetic stroke patients. Thirty-six stroke survivors (acute stage group (ASG), n = 11; subacute stage group (SSG), n = 15; chronic stage group (CSG), n = 10) consistently received Walkbot RAGT for 30 min/session, thrice a week, for 4 weeks. Six clinical outcome variables, including the Fugl–Meyer Assessment (FMA), Berg Balance Scale (BBS), Trunk Impairment Scale (TIS), Modified Barthel Index (MBI), Modified Ashworth Scale (MAS), and Mini-Mental State Examination, were examined before and after the intervention. Significant differences in the FMA, BBS, TIS, and MBI were observed between the ASG and the SSG or CSG. A significant time effect was observed for all variables, except for the MAS, in the ASG and SSG, whereas significant time effects were noted for the FMA, BBS, and TIS in the CSG. Overall, Walkbot RAGT was more favorable for acute stroke patients than for those with subacute or chronic stroke. This provides the first clinical evidence for the optimal intervention timing for RAGT in stroke. [ABSTRACT FROM AUTHOR]

Objective To investigate the serum level of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) -specific RBD IgG antibody (SARS-CoV-2 IgG antibody for short) in children with SARS-CoV-2 Omicron variant infection during the recovery stage, as well as the protective effect of SARS-CoV-2 vaccination against Omicron infection. Methods A retrospective analysis was performed on 110 children who were diagnosed with coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 Omicron variant infection in Tianjin of China from January 8 to February 7, 2022. According to the status of vaccination before diagnosis, they were divided into a booster vaccination (3 doses) group with 2 children, a complete vaccination (2 doses) group with 90 children, an incomplete vaccination (1 dose) group with 5 children, and a non-vaccination group with 13 children. The clinical data and IgG level were compared among the 4 groups. Results The complete vaccination group had a significantly higher age than the non-vaccination group at diagnosis (P<0.05), and there was a significant difference in the route of transmission between the two groups (P<0.05). There were no significant differences among the four groups in sex, clinical classification, and re-positive rate of SARS-CoV-2 nucleic acid detection (P>0.05). All 97 children were vaccinated with inactivated vaccine, among whom 85 children (88%) were vaccinated with BBIBP-CorV Sinopharm vaccine (Beijing Institute of Biological Products, Beijing, China). At 1 month after diagnosis, the booster vaccination group and the complete vaccination group had a significantly higher level of SARS-CoV-2 IgG antibody than the non-vaccination group (P<0.05), and at 2 months after diagnosis, the complete vaccination group had a significantly higher level of SARS-CoV-2 IgG antibody than the non-vaccination group (P<0.05). For the complete vaccination group, the level of SARS-CoV-2 IgG antibody at 2 months after diagnosis was significantly lower than that at 1 month after diagnosis (P<0.05). Conclusions Vaccination with inactivated SARS-CoV-2 vaccine has a protective effect against Omicron infection in children. For children vaccinated with 2 doses of the vaccine who experience Omicron infection, there may be a slight reduction in the level of SARS-CoV-2 IgG antibody at 2 months after diagnosis. [ABSTRACT FROM AUTHOR]

Seedlings in regenerating layer are frequently attacked by herbivorous insects, while the combined effects of defoliation and shading are not fully understood. In the present study, two Leguminosae species (Robinia pseudoacacia and Amorpha fruticosa) were selected to study their responses to combined light and defoliation treatments. In a greenhouse experiment, light treatments (L+, 88% vs L−, 8% full sunlight) and defoliation treatments (CK, without defoliation vs DE, defoliation 50% of the upper crown) were applied at the same time. The seedlings' physiological and growth traits were determined at 1, 10, 30, and 70 days after the combined treatment. Our results showed that the effects of defoliation on growth and carbon allocation under high light treatments in both species were mainly concentrated in the early stage (days 1–10). R. pseudoacacia can achieve growth recovery within 10 days after defoliation, while A. fruticosa needs 30 days. Seedlings increased SLA and total chlorophyll concentration to improve light capture efficiency under low light treatments in both species, at the expense of reduced leaf thickness and leaf lignin concentration. The negative effects of defoliation treatment on plant growth and non-structural carbohydrates (NSCs) concentration in low light treatment were significantly higher than that in high light treatment after recovery for 70 days in R. pseudoacacia , suggesting sufficient production of carbohydrate would be crucial for seedling growth after defoliation. Plant growth was more sensitive to defoliation and low light stress than photosynthesis, resulting in NSCs accumulating during the early period of treatment. These results illustrated that although seedlings could adjust their resource allocation strategy and carbon dynamics in response to combined defoliation and light treatments, individuals grown in low light conditions will be more suppressed by defoliation. Our results indicate that we should pay more attention to understory seedlings' regeneration under the pressure of herbivorous insects. [ABSTRACT FROM AUTHOR]

Seedlings in regenerating layer are frequently attacked by herbivorous insects, while the combined effects of defoliation and shading are not fully understood. In the present study, two Leguminosae species (Robinia pseudoacacia and Amorpha fruticosa) were selected to study their responses to combined light and defoliation treatments. In a greenhouse experiment, light treatments (L+, 88% vs L−, 8% full sunlight) and defoliation treatments (CK, without defoliation vs DE, defoliation 50% of the upper crown) were applied at the same time. The seedlings’ physiological and growth traits were determined at 1, 10, 30, and 70 days after the combined treatment. Our results showed that the effects of defoliation on growth and carbon allocation under high light treatments in both species were mainly concentrated in the early stage (days 1–10). R. pseudoacacia can achieve growth recovery within 10 days after defoliation, while A. fruticosa needs 30 days. Seedlings increased SLA and total chlorophyll concentration to improve light capture efficiency under low light treatments in both species, at the expense of reduced leaf thickness and leaf lignin concentration. The negative effects of defoliation treatment on plant growth and non-structural carbohydrates (NSCs) concentration in low light treatment were significantly higher than that in high light treatment after recovery for 70 days in R. pseudoacacia, suggesting sufficient production of carbohydrate would be crucial for seedling growth after defoliation. Plant growth was more sensitive to defoliation and low light stress than photosynthesis, resulting in NSCs accumulating during the early period of treatment. These results illustrated that although seedlings could adjust their resource allocation strategy and carbon dynamics in response to combined defoliation and light treatments, individuals grown in low light conditions will be more suppressed by defoliation. Our results indicate that we should pay more attention to understory seedlings’ regeneration under the pressure of herbivorous insects.

This study was designed to determine the best intervention time (acute, subacute, and chronic stages) for Walkbot robot-assisted gait training (RAGT) rehabilitation to improve clinical outcomes, including sensorimotor function, balance, cognition, and activities of daily living, in hemiparetic stroke patients. Thirty-six stroke survivors (acute stage group (ASG), n = 11; subacute stage group (SSG), n = 15; chronic stage group (CSG), n = 10) consistently received Walkbot RAGT for 30 min/session, thrice a week, for 4 weeks. Six clinical outcome variables, including the Fugl–Meyer Assessment (FMA), Berg Balance Scale (BBS), Trunk Impairment Scale (TIS), Modified Barthel Index (MBI), Modified Ashworth Scale (MAS), and Mini-Mental State Examination, were examined before and after the intervention. Significant differences in the FMA, BBS, TIS, and MBI were observed between the ASG and the SSG or CSG. A significant time effect was observed for all variables, except for the MAS, in the ASG and SSG, whereas significant time effects were noted for the FMA, BBS, and TIS in the CSG. Overall, Walkbot RAGT was more favorable for acute stroke patients than for those with subacute or chronic stroke. This provides the first clinical evidence for the optimal intervention timing for RAGT in stroke.

The service performances of asphalt pavement, especially rutting, will be inevitably affected by climate change. However, existing studies have generally focused on the rutting depth and rutting life, and thus became insufficient for comprehensively evaluating the influence of climate change on rutting over the service life. A resilience assessment method for asphalt pavement rutting is developed to solve the above problem. First, the original resilience method is extended to fit the system whose performance level continues to decline. Then, the calculation formulas of rutting resilience are derived by combining the rutting prediction model and the level assessment model. Subsequently, the influence degrees of climate change in representative cities on rutting resilience are studied. The results suggest that neglecting climate change in rutting design of asphalt pavement will lead to insufficient resilience, especially in northern China. Furthermore, the predicted temperature under RCP8.5 should be employed for asphalt pavement design. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the serum level of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific RBD IgG antibody (SARS-CoV-2 IgG antibody for short) in children with SARS-CoV-2 Omicron variant infection during the recovery stage, as well as the protective effect of SARS-CoV-2 vaccination against Omicron infection., Methods: A retrospective analysis was performed on 110 children who were diagnosed with coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 Omicron variant infection in Tianjin of China from January 8 to February 7, 2022. According to the status of vaccination before diagnosis, they were divided into a booster vaccination (3 doses) group with 2 children, a complete vaccination (2 doses) group with 90 children, an incomplete vaccination (1 dose) group with 5 children, and a non-vaccination group with 13 children. The clinical data and IgG level were compared among the 4 groups., Results: The complete vaccination group had a significantly higher age than the non-vaccination group at diagnosis ( P <0.05), and there was a significant difference in the route of transmission between the two groups ( P <0.05). There were no significant differences among the four groups in sex, clinical classification, and re-positive rate of SARS-CoV-2 nucleic acid detection ( P >0.05). All 97 children were vaccinated with inactivated vaccine, among whom 85 children (88%) were vaccinated with BBIBP-CorV Sinopharm vaccine (Beijing Institute of Biological Products, Beijing, China). At 1 month after diagnosis, the booster vaccination group and the complete vaccination group had a significantly higher level of SARS-CoV-2 IgG antibody than the non-vaccination group ( P <0.05), and at 2 months after diagnosis, the complete vaccination group had a significantly higher level of SARS-CoV-2 IgG antibody than the non-vaccination group ( P <0.05). For the complete vaccination group, the level of SARS-CoV-2 IgG antibody at 2 months after diagnosis was significantly lower than that at 1 month after diagnosis ( P <0.05)., Conclusions: Vaccination with inactivated SARS-CoV-2 vaccine has a protective effect against Omicron infection in children. For children vaccinated with 2 doses of the vaccine who experience Omicron infection, there may be a slight reduction in the level of SARS-CoV-2 IgG antibody at 2 months after diagnosis. Citation:Chinese Journal of Contemporary Pediatrics, 2022, 24(7): 736-741 .

Objective: To observe the effect of thumb-tack needles based on " Biaoben acupoint compatibility" on sequela symptoms, mental state and pulmonary ventilation function in patients with coronavirus disease 2019 (COVID-19) during recovery period., Methods: Fifty cases of COVID-19 during recovery period were randomly divided into an observation group and a control group, 25 cases in each group. The patients in the observation group were treated with thumb-tack needles at Guanyuan (CV 4), Zusanli (ST 36) and Taiyuan (LU 9). The patients in the control group were treated with sham thumb-tack needles at identical acupoints as the observation group. The treatment in the two groups was given once a day, 7-day treatment was taken as a course of treatment, and totally two courses of treatment were given. The TCM symptom score, Hamilton anxiety scale (HAMA) score, Hamilton depression scale (HAMD) score, pulmonary function (forced vital capacity [FVC], forced expiratory volume in the first second [FEV1], peak expiratory flow [PEF]), the severity of pulmonary ventilation dysfunction and pulmonary imaging changes in the two groups were compared before and after treatment., Results: Compared before treatment, the total scores and each item scores of TCM symptom scale, HAMA scores and HAMD scores in the two groups were reduced after treatment ( P <0.05). Except for the symptom scores of dry throat and dry stool, the total score and each item score of TCM symptom scale, HAMA score and HAMD score in the observation group were lower than those in the control group ( P <0.05). Compared before treatment, FVC, FEV1 and PEF in the two groups were increased after treatment ( P <0.05), and those in the observation group were higher than the control group ( P <0.05). The severity of pulmonary ventilation dysfunction in the two groups was reduced after treatment ( P <0.05), and the severity in the observation group was better than that in the control group ( P <0.05). After treatment, the lung shadow area in the two groups was decreased ( P <0.05), and that in the observation group was smaller than the control group ( P <0.05). The improvement of imaging change in the observation group was better than that in the control group ( P <0.05)., Conclusion: The thumb-tack needles based on " Biaoben acupoint compatibility" could significantly reduce the sequela symptoms, anxiety and depression in patients with COVID-19 during recovery stage, and improve the pulmonary ventilation function.