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An ERA5 tropospheric parameters-augmented approach for improving GNSS precise point positioning
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作者 Liangke Huang feifan liu +4 位作者 Lijie Guo Guiwen Lan Lv Zhou Cheng Wang Lilong liu 《Geodesy and Geodynamics》 EI CSCD 2023年第5期467-476,共10页
Precise Point Positioning(PPP) technology has developed into a potent instrument for geodetic positioning, ionospheric modeling, tropospheric atmospheric parameter detection, and seismic monitoring.As atmospheric rean... Precise Point Positioning(PPP) technology has developed into a potent instrument for geodetic positioning, ionospheric modeling, tropospheric atmospheric parameter detection, and seismic monitoring.As atmospheric reanalysis data products’ accuracy and spatiotemporal resolution have improved recently, it has become important to apply these products to obtain high-accuracy tropospheric delay parameters, like zenith tropospheric delay(ZTD) and tropospheric horizontal gradient. These tropospheric delay parameters can be applied to PPP to reduce the convergence time and to increase the accuracy in the vertical direction of the position. The European Centre for Medium-Range Weather Forecasts Reanalysis 5(ERA5) atmospheric reanalysis data is the latest product with a high spatiotemporal resolution released by the European Center for Medium-Range Weather Forecasts(ECMWF). Only a few researches have evaluated the application of ERA5 data to Global Navigation Satellite System(GNSS)PPP. Therefore, this study compared and validated the ZTD products derived from ERA5 data using ZTD values provided by 290 global International GNSS Service(IGS) stations for 2016-2017. The results indicated a stable performance for ZTD, with annual average bias and RMS values of 0.23 cm and 1.09 cm,respectively. Further, GNSS observations for one week in each of the four seasons(spring: DOY 92-98;summer: DOY 199-205;autumn: DOY 275-281;and winter: DOY 22-28) from 34 multi-GNSS experiments(MGEX) stations distributed globally in 2016 were considered to evaluate the performance of ERA5-derived tropospheric delay products in GNSS PPP. The performance of ERA5-enhanced PPP was compared with that of the two standard GNSS PPP schemes(without estimated tropospheric horizontal gradient and with estimated tropospheric horizontal gradient). The results demonstrated that ERA5-enhanced GNSS PPP showed no significant improvement in the convergence times in both the Eastern(E) and Northern(N) directions, while the average convergence time over four weeks in the vertical(U)direction improved by 53.3% and 52.7%, respectively(in the case of pngm station). The average convergence times for each week in the U direction of the northern and southern hemisphere stations indicated a decrease of 16.3%, 12.6%, 9.6%, and 9.1%, and 16.9%, 9.6%, 8.9%, and 14.5%, respectively.Regarding positioning accuracy, ERA5-enhanced PPP showed an improvement of 13.3% and 16.2% over the two standard PPP schemes in the U direction, respectively. No significant improvement in the positioning performance was observed in both the E and N directions. Thus, this study demonstrated the potential application of the ERA5 tropospheric parameters-augmented approach to Beidou navigation and positioning. 展开更多
关键词 Precise point positioning ERA5 atmospheric reanalysis data Multi-GNSS Tropospheric delay
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A comparative study of the electrical characteristics of positive and negative narrow bipolar events
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作者 feifan liu BaoYou Zhu +3 位作者 HeLin Zhou GaoPeng Lu Ming Ma JiuHou Lei 《Earth and Planetary Physics》 CAS CSCD 2023年第6期675-683,共9页
Narrow bipolar events(NBEs)are intriguing intra-cloud discharge that have attracted enormous interest in the lightning community.They come with two polarities that dominate at different altitudes in thunderclouds.The ... Narrow bipolar events(NBEs)are intriguing intra-cloud discharge that have attracted enormous interest in the lightning community.They come with two polarities that dominate at different altitudes in thunderclouds.The sources of negative NBEs are usually located near the top of thunderclouds;those of positive NBEs are at the middle levels.NBEs may occur at the onset of lightning.The electrical properties of NBEs remain poorly understood.We present here the first comparative study of the electrical characteristics of negative and positive NBEs.To derive electrical parameters from the fast electric field change waveforms of 1673 positive NBEs and 364 negative NBEs recorded by the Jianghuai Area Sferic Array(JASA)in China,we use an improved method based on the transmission line model.This approach concludes that negative NBEs occurring at high altitudes tend to produce a narrower current pulse and take a shorter time to traverse the channel than their positive counterparts.Moreover,compared to positive NBEs,a larger portion of negative NBEs are associated with slightly greater peak current moments but smaller overall charge moments.The differences reported herein between electrical properties of negative and positive NBEs suggest that charge distribution in NBE-producing thunderstorms tends to vary systematically with altitude. 展开更多
关键词 LIGHTNING THUNDERSTORM narrow bipolar events
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Investigation and Analysis of Catheter-Associated Skin Impairment in PICC’s Patients in Jingzhou City 被引量:1
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作者 Qianwen Li Hong Wang +1 位作者 feifan liu Yiqing He 《Journal of Biosciences and Medicines》 2020年第10期38-46,共9页
Objective: To understand the status quo of PICC Catheter-associated Skin Impairment (CASI) in some hospitals at all levels in Jingzhou city, and to explore the risk factors for PICC Catheter-associated Skin Impairment... Objective: To understand the status quo of PICC Catheter-associated Skin Impairment (CASI) in some hospitals at all levels in Jingzhou city, and to explore the risk factors for PICC Catheter-associated Skin Impairment. Methods: From June 2019 to July 2020, a self-made questionnaire for CASI status was used to facilitate the extraction of CASI patients in PICC in some hospitals at all levels in Jingzhou city. Local skin lesions were collected and classified during PICC maintenance, and the damage types, occurrence frequency and related influencing factors of CASI were counted to identify independent risk factors. Results: In this study, there were 173 cases of CASI in PICC’s patients including local infection 56.1% (97/173), exudation at the puncture site 16.8% (29/173), irritant dermatitis 21.4% (37/173), allergic dermatitis 4.6% (8/173), and tension injury 1.2% (2/173). After univariate analysis, there were statistically significant differences between CASI occurrence type and duration of catheter wear, age, underlying disease, skin moisture and hyperhidrosis, PICC maintenance as required, hospital grade maintenance and intermittent chemotherapy (P < 0.05). Then, disordered multiple Logistic regression analysis was performed, and exudation at the puncture site was used as the reference group. The results showed that patients with PICC were more likely to have CASI if they were aged, long catheter time, had diabetes, had moist and sweaty skin, and were in the intermittent stage of chemotherapy. Conclusion: The incidence of CASI is high in patients aged 70 - 79 years, and local infection is the most common. PICC’s patients with diabetes are at high risk of CASI. PICC’s patients with excessive sweating are more likely to have CASI. The intermittent stage of chemotherapy is the excessive CASI;time with tube affects CASI occurrence. 展开更多
关键词 PICC CASI Status Survey Multifactor Analysis
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Frailty Syndrome Prevalence and Its Correlation with Cognitive Function in Elderly Surgical Inpatients
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作者 feifan liu Yanling Heng +1 位作者 Qianwen Li Qingyi He 《Journal of Biosciences and Medicines》 2020年第10期148-156,共9页
<strong>Background:</strong> Frailty is a geriatric syndrome, and a common negative consequence of aging, which shares some obvious characteristics as cognitive impairment. Preventing and relieving frailty... <strong>Background:</strong> Frailty is a geriatric syndrome, and a common negative consequence of aging, which shares some obvious characteristics as cognitive impairment. Preventing and relieving frailty may reduce the possibility of developing cognitive impairment. <strong>Objective: </strong>This study aimed to investigate frailty prevalence and its correlation with cognitive function in elderly surgical inpatients. <strong>Methods: </strong>We enrolled a random sample of elderly surgical inpatients from Jingzhou from June 2020 to August 2020. We used a self-made registration sheet to collect their demographic data (gender, age, nationality, educational level and monthly income), and used the FRAIL Scale to assess the prevalence of frailty, and used the Mini-Mental State Examination (MMSE) to assess cognitive function. We used multiple linear regression analysis to explore the correlation between frailty level and demographic data, then Pearson correlation analysis was performed to analyze the correlation between frailty and cognitive function. <strong>Results: </strong>In the 143 elderly surgical inpatients, prevalence of frail was seen in 29 (20.3%), and pre-frail state was found in 64 (44.8%). Only 50 (34.9%) were in healthy state. Cognitive impairment was seen in 28 (19.5%). Pearson correlation analysis showed that the frail scoring was correlated with cognitive function in elderly surgical inpatients (r = -0.378, P < 0.05). <strong>Conclusion:</strong> The prevalence of frailty is high in elderly surgical inpatients, which is closely related to age and gender. Elderly surgical inpatients have high cognitive impairment, and frailty appears strongly associated with cognitive status. The findings suggest that attention should be paid to the frailty and cognitive function in the elderly surgical inpatients by pro-vision of effective interventions. 展开更多
关键词 Frailty Syndrome Cognitive Impairment Aged Surgical Inpatients Mini Mental State Examination
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Locating Parent Lightning Strokes of Sprites Observed over a Mesoscale Convective System in Shandong Province,China 被引量:6
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作者 Anjing HUANG Gaopeng LU +5 位作者 Hongbo ZHANG feifan liu Yanfeng FAN Baoyou ZHU Jing YANG Zhichao WANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2018年第11期1396-1414,共19页
In this paper, we report the location results for the parent lightning strokes of more than 30 red sprites observed over an asymmetric mesoscale convective system(MCS) on 30 July 2015 in Shandong Province, China, with... In this paper, we report the location results for the parent lightning strokes of more than 30 red sprites observed over an asymmetric mesoscale convective system(MCS) on 30 July 2015 in Shandong Province, China, with a long-baseline lightning location network of very-low-frequency/low-frequency magnetic field sensors. The results show that almost all of these cloud-to-ground(CG) strokes are produced during the mature stage of the MCS, and are predominantly located in the trailing stratiform region, which is similar to analyses of sprite-productive MCSs in North America and Europe. Comparison between the location results for the sprite-producing CG strokes and those provided by the World Wide Lightning Location Network(WWLLN) indicates that the location accuracy of WWLLN for intense CG strokes in Shandong Province is typically within 10 km, which is consistent with the result based on analysis of 2838 sprite-producing CG strokes in the continental United States. Also, we analyze two cases where some minor lightning discharges in the parent flash of sprites can also be located, providing an approach to confine the thundercloud region tapped by the sprite-producing CG strokes. 展开更多
关键词 red SPRITES positive cloud-to-ground strokes(+CGs) MESOSCALE CONVECTIVE system(MCS)
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Triangulation of red sprites observed above a mesoscale convective system in North China 被引量:4
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作者 YongPing Wang GaoPeng Lu +14 位作者 Ming Ma HongBo Zhang YanFeng Fan GuoJin liu ZheRun Wan Yu Wang Kang-Ming Peng ChangZhi Peng feifan liu BaoYou Zhu BinBin Ni XuDong Gu Long Chen Juan Yi RuoXian Zhou 《Earth and Planetary Physics》 CSCD 2019年第2期111-125,共15页
The triangulation of red sprites was obtained, based on concurrent observations over a mesoscale convective system(MCS) in North China from two stations separated by about 450 km. In addition, broadband sferics from t... The triangulation of red sprites was obtained, based on concurrent observations over a mesoscale convective system(MCS) in North China from two stations separated by about 450 km. In addition, broadband sferics from the sprite-producing lightning were measured at five ground stations, making it possible to locate and identify the individual causative lightning discharges for different elements in this dancing sprite event. The results of our analyses indicate that the sprites were produced above the trailing stratiform region of the MCS, and their parent strokes were located mainly in the peripheral area of the stratiform. The lateral offset between sprites and causative strokes ranges from a few km to more than 50 km. In a particularly bright sprite, with a distinct halo feature and streamers descending down to an altitude of approximately 48 km, the sprite current signal identified in the electric sferic, measured at a range of about 1,110 km, peaked at approximately 1 ms after the return stroke. 展开更多
关键词 SPRITE TRIANGULATION peak current hybrid location
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Research Progress on Modern Biological Mechanism of Chinese Medicine in Prevention and Treatment of Gouty Nephropathy
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作者 feifan liu Shifang LUO +4 位作者 Yan WAN Linao ZHANG Xue WU Yuhuan XIE Peixin GUO 《Medicinal Plant》 2024年第4期129-132,共4页
Chinese medicine prevention and treatment of gouty nephropathy often uses single drugs and compound formulae to regulate uric acid,which has the effect of lowering uric acid,protecting the kidneys and improving clinic... Chinese medicine prevention and treatment of gouty nephropathy often uses single drugs and compound formulae to regulate uric acid,which has the effect of lowering uric acid,protecting the kidneys and improving clinical symptoms.In conclusion,the mechanism of action of Chinese medicine against gouty nephropathy mainly involves oxidative stress,inflammatory response,etc.,with a view to providing new ideas and methods for the prevention and treatment of gouty nephropathy by Chinese medicine. 展开更多
关键词 Chinese medicine Gouty nephropathy Mechanism of action Research progress
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Research Progress of Dai and Western Medicine in the Treatment of Gouty Arthritis
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作者 feifan liu Shifang LUO +4 位作者 Yan WAN Linao ZHANG Xue WU Yuhuan XIE Peixin GUO 《Medicinal Plant》 2024年第4期118-121,共4页
This paper reviews the pathogenesis,diagnostic criteria,and treatment means of gouty arthritis from the perspectives of Western medicine and Dai medicine in order to provide a reference for clinical medication.
关键词 Gout Dai medicine Western medicine Research progress
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Risk Factors for Acute Kidney Injury in Patients Receiving Antibiotic Therapy:A Systematic Review and Meta-Analysis
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作者 feifan liu Yuanmei BAI +2 位作者 Yan WAN Yuhuan XIE Peixin GUO 《Medicinal Plant》 2024年第4期59-68,共10页
[Objectives]To systematically analyze the risk factors for acute kidney injury(AKI)in patients treated with antibiotics and to conduct a meta-analysis of published clinical studies.[Methods]PubMed,Web of Science,and E... [Objectives]To systematically analyze the risk factors for acute kidney injury(AKI)in patients treated with antibiotics and to conduct a meta-analysis of published clinical studies.[Methods]PubMed,Web of Science,and Embase were searched for relevant cohort and case-control studies from January 1,2001,to October 31,2022.Meta-analysis was performed using RevMan5.4 and StataMP15.[Results]A total of 22 studies were included.Regarding patient factors,serum creatinine(SCr;MD=1.03,95%CI of-0.07 to-0.02)was associated with increased antibiotic-associated AKI.Regarding the comorbidities and clinical factors,diabetes(OR=1.34,95%CI of 1.06 to 1.69,tumor(OR=2.07,95%CI of 1.13 to 3.79),pneumonia(OR=1.83,95%CI of 1.24 to 2.71),mechanical ventilation(OR=3.44,95%CI of 1.93 to 6.12),and ICU admission(OR=2.83,95%CI of 2.13 to 3.75)increased the risk of AKI in patients receiving antibiotic therapy.Regarding drug factors,diuretics(OR=2.76,95%CI of 2.16 to 3.52)increased the risk of antibiotic-associated AKI.[Conclusions]This paper may assist clinicians in predicting the risk factors for AKI in patients receiving antibiotic therapy. 展开更多
关键词 Acute kidney injury(AKI) Antibiotics Risk factors Meta-analysis
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Construction and evaluation of a novel prognostic risk model of aging-related genes in bladder cancer
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作者 Delin Wang Hao Ning +6 位作者 Haihu Wu Yufeng Song Yaru Chu feifan liu Zhenlin Zhao Fei Wu Jiaju Lyu 《Current Urology》 2023年第4期236-245,共10页
Background:Bladder cancer(BLCA)is the most common malignancy of the urinary system.Muscle-invasive bladder cancer(MIBC),which constitutes approximately 25%of all BLCA cases,is characterized by frequent recurrence and ... Background:Bladder cancer(BLCA)is the most common malignancy of the urinary system.Muscle-invasive bladder cancer(MIBC),which constitutes approximately 25%of all BLCA cases,is characterized by frequent recurrence and early onset of metastasis.Bladder cancer most commonly occurs in elderly patients and is significantly associated with aging.However,the prognostic value of age-related genes in BLCA,especially in MIBC,remains unclear.Materials and methods:Training and testing sets were obtained from The Cancer Genome Atlas BLCA project.Differentially expressed genes between BLCA and normal samples intersected with human aging-related genes.Univariate Cox regression and least absolute shrinkage and selection operator regression analyses were used to identify prognostic aging-related signatures,followed by the construction of a risk score model and nomogram.Kaplan-Meier and receiver operating characteristic analyses were conducted to assess the predictive power.An independent BLCA cohort of 165 samples was included for external validation.The CIBERSORT algorithm was used to explore the characteristics of the immune microenvironment.Results:Seven genes(IGF1,NGF,GCLM,PYCR1,EFEMP1,APOC3,and IFNB1)were identified by Cox and least absolute shrinkage and selection operator analyses.After combining the gene signature with the clinical parameters of patients with BLCA,a risk-prognosis model and nomogram were constructed and validated with the testing set.Bladder cancer cases with high 7-gene signature scores(high-risk group)and low scores(low-risk group)showed distinct prognoses.Furthermore,7 types of immune cells were significantly altered between the low-and high-risk groups.Conclusions:Collectively,our data provide a 7-gene signature that serves as a potential biomarker for BLCA,especially MIBC.Moreover,this 7-gene signature highlights the role of the tumor immune microenvironment in prognosis and thus might be related to the response to anti-programmed cell death protein 1-based immunotherapy. 展开更多
关键词 Bladder cancer PROGNOSIS Aging-related genes BIOMARKER Immune microenvironment Overall survival
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Exploring the Mechanism of Action of Gastrodin in Parkinson's Disease Based on Network Pharmacology
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作者 feifan liu Shifang LUO +4 位作者 Yan WAN Linao ZHANG Xue WU Yuhuan XIE Peixin GUO 《Medicinal Plant》 2024年第4期16-19,25,共5页
[Objectives]To explore the mechanism of action of gastrodin in the treatment of Parkinson's disease(PD)by employing network pharmacology technology,and to provide a scientific theoretical basis for the rational cl... [Objectives]To explore the mechanism of action of gastrodin in the treatment of Parkinson's disease(PD)by employing network pharmacology technology,and to provide a scientific theoretical basis for the rational clinical application of gastrodin.[Methods]The target of gastrodin was identified through a search of the SwissTargetPrediction database.The keyword"Parkinson Disease"was employed to identify the pertinent targets of PD in the GeneCards and OMIM databases.The relationship between gastrodin and PD was elucidated,and a Veen map was constructed to identify the genes that were common to both.A total of 52 common drug targets associated with PD as identified in the Wayne chart were imported into the String database(https://string-db.org/)for protein-protein interaction prediction.Subsequently,Cytoscape 3.9.1 software was employed to construct a"drug-target"network.The potential targets of gastrodin in the treatment of PD were then imported into the DAVID database,where GO analysis and KEGG enrichment results were obtained.[Results]A total of 22 core targets and 53 related pathways of gastrodin were identified as potentially beneficial for the treatment of PD.[Conclusions]Gastrodin may be a potential therapeutic agent for the treatment of PD by modulating the biological process of apoptosis,affecting the relevant pathways such as the IL-17 signaling pathway and the TNF signaling pathway,and acting on GAPDH,EGFR,CASP3,MMP9 and other targets. 展开更多
关键词 Parkinson's disease Network pharmacology Gastrodin
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Advances in Research of Chinese Medicine Tianma in the Treatment of Parkinson's Disease
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作者 feifan liu Shifang LUO +4 位作者 Yan WAN Linao ZHANG Xue WU Yuhuan XIE Peixin GUO 《Medicinal Plant》 2024年第4期133-135,共3页
In this study,a systematic review was conducted on the experimental study as well as the clinical application of Tianma(Gastrodia elata Blume),a traditional Chinese medicine,in the prevention and treatment of Parkinso... In this study,a systematic review was conducted on the experimental study as well as the clinical application of Tianma(Gastrodia elata Blume),a traditional Chinese medicine,in the prevention and treatment of Parkinson's disease(PD).On this basis,a summary and outlook were made,so as to provide ideas and theoretical basis for the study,development and utilization of Tianma PD field. 展开更多
关键词 Tianma(Gastrodia elata Blume) Parkinson's disease(PD) Clinical application
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