Debt,sleep deprivation and psychological distress among online ride-hailing drivers:evidence from China

An online ride-hailing driver(ORHD)refers to a driver who takes orders and provides rental car services to passengers via an online service platform.1 ORHD plays a significant role in the urban transport system worldwide,operating through many platforms.According to official data from the Chinese Ministry of Transport,a total of 1.6 million vehicle transport permits were issued by the end of March 2022.

Low-Frequency Oscillation Analysis of Grid-Connected VSG System Considering Multi-Parameter Coupling

With the increasing integration of new energy generation into the power system and the massive withdrawal of traditional fossil fuel generation,the power system is faced with a large number of stability problems.The phenomenon of low-frequency oscillation caused by lack of damping and moment of inertia is worth studying.In recent years,virtual synchronous generator(VSG)technique has been developed rapidly because it can provide considerable damping and moment of inertia.While improving the stability of the system,it also inevitably causes the problem of active power oscillation,especially the low mutual damping between the VSG and the power grid will make the oscillation more severe.The traditional time-domain state-space method cannot reflect the interaction among state variables and study the interaction between different nodes and branches of the power grid.In this paper,a frequency-domain method for analyzing low-frequency oscillations considering VSG parameter coupling is proposed.First,based on the rotor motion equation of the synchronous generator(SG),a secondorder VSG model and linearized power-frequency control loop model are established.Then,the differences and connections between the coupling of key VSG parameters and low-frequency oscillation characteristics are studied through frequency domain analysis.The path and influencemechanism of a VSG during low-frequency power grid oscillations are illustrated.Finally,the correctness of the theoretical analysis model is verified by simulation.

Exosomal S100A4 derived from highly metastatic hepatocellular carcinoma cells promotes metastasis by activating STAT3

Intercellular cross-talk plays important roles in cancer progression and metastasis.Yet how these cancer cells interact with each other is still largely unknown.Exosomes released by tumor cells have been proved to be effective cell-to-cell signal mediators.We explored the functional roles of exosomes in metastasis and the potential prognostic values for hepatocellular carcinoma(HCC).Exosomes were extracted from HCC cells of different metastatic potentials.The metastatic effects of exosomes derived from highly metastatic HCC cells(HMH)were evaluated both in vitro and in vivo.Exosomal proteins were identified with iTRAQ mass spectrum and verified in cell lines,xenograft tumor samples,and functional analyses.Exosomes released by HMH significantly enhanced the in vitro invasion and in vivo metastasis of low metastatic HCC cells(LMH).S100 calcium-binding protein A4(S100A4)was identified as a functional factor in exosomes derived from HMH.S100A4r,ch exosomes significantly promoted tumor metastasis both in vitro and in vivo compared with S100A4^(rich) exosomes or controls.Moreover,exosomal S100A4 could induce expression of osteopontin(OPN),along with other tumor metastasis/stemness-related genes.Exosomal S100A4 activated OPN transcription via STAT3 phosphorylation.HCC patients with high exosomal S100A4 in plasma also had a poorer prognosis.In conclusion,exosomes from HMH could promote the metastatic potential of LMH,and exosomal S100A4 is a key enhancer for HCC metastasis,activating STAT3 phosphorylation and up-regulating OPN expression.This suggested exosomal S100A4 to be a novel prognostic marker and therapeutic target for HCC metastasis.

Clinical features of 162 fatal cases of COVID-19:a multi-center retrospective study

Background:The coronavirus disease 2019(COVID-19)has affected approximately 2 million individuals worldwide;however,data regarding fatal cases have been limited.Objective:To report the clinical features of 162 fatal cases of COVID-19 from 5 hospitals in Wuhan between December 30,2019 and March 12,2020.Methods:The demographic data,signs and symptoms,clinical course,comorbidities,laboratory findings,computed tomographic(CT)scans,treatments,and complications of the patients with fatal cases were retrieved from electronic medical records.Results:The median patient age was 69.5(interquartile range:63.0–77.25)years,and 80%of the patients were over 61 years.A total of 112(69.1%)patients were men.Hypertension(45.1%)was the most common comorbidity,while 59(36.4%)patients had no comorbidity.At admission,131(81.9%)patients had severe or critical COVID-19,whereas 39(18.1%)patients with hypertension or chronic lung disease had moderate COVID-19.In total,126(77.8%)patients received antiviral treatment,while 132(81.5%)patients received glucocorticoid treatment.A total of 116(71.6%)patients were admitted to the intensive care unit(ICU),and 137(85.1%)patients received mechanical ventilation.Most patients received mechanical ventilation before ICU admission.Approximately 93.2%of the patients developed respiratory failure or acute respiratory distress syndrome.There were no significant differences in the inhospital survival time among the hospitals(P=0.14).Conclusion:Young patients with moderate COVID-19 without comorbidity at admission could also develop fatal outcomes.The in-hospital survival time of the fatal cases was similar among the hospitals of different levels in Wuhan.

Correlation between clinical course and radiographic development on CT scan in patients with COVID-19

Background:To analyze the correlation between clinical course and radiographic development on computed tomography(CT)in patients with confirmed coronavirus disease 2019(COVID-19)and to provide more evidence for treatment.Methods:This retrospective,observational,cohort study enrolled 49 patients with Reverse transcription-polymerase chain reaction(RT-PCR)-confirmed COVID-19,which included 30 patients admitted to the intensive care unit(ICU)of Wuhan Third Hospital and 19 patients either admitted to or receiving telemedicine consultation from Shanghai General Hospital,Shanghai Xuhui Dahua Hospital,and hospitals in other provinces.CT scans were performed in all enrolled patients and the radiographic features including simple ground-glass opacities(GGOs),GGO with interlobular septal thickening,consolidations with GGO,and consolidations only were monitored by repeating the CT.The progression of these radiographic features was analyzed in combination with their clinical staging and the time interval between onset of symptoms to CT.Results:Based on illness severity,the 49 patients were classified into four stages:mild(n=6),moderate(n=12),severe(n=16),and critically ill(n=15).The CT findings were classified into three phases:early(n=5),progres-sion(n=39),and recovery(n=5).Among the 49 patients,9 had bilateral diffuse GGO or diffuse consolidations(white lungs)and were counted as 18 lesions.Three patients had no abnormal findings on initial CT,but their repeat CT showed new lesions.In all,we identified 892 lesions including simple GGO,GGO with interlobular septal thickening,consolidations with GGO,and consolidations only.Conclusions:Most patients had pulmonary lesions on the posterior,inferior,and peripheral lung fields on CT.The development of GGO with interlobular septal thickening,GGO with consolidations,and consolidations only happened mainly between day 8 and 14.The emergence of consolidations may suggest the progression to the severe phase of the illness,whereas simple consolidations or“white lung”may suggest a critically ill phase.