1,203 results on '"Lixin Guo"'
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2. Treatments, medical expenses and complications of hospital outpatient healthcare associated with stroke in patients with diabetes in China: a retrospective analysis of the Beijing Municipal Medical Insurance Database
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Yi Zeng, Ying Luo, Zhen Zhang, Weihao Wang, Lixin Guo, SiTing Liang, Hanming Wang, JiaDong Zeng, JingTao Qiao, and Jingwen Fan
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Medicine - Abstract
Objectives Diabetes is closely associated with risk of stroke and its adverse sequelae. Approximately 20%–33% of patients with stroke have diabetes. In China, however, it is unclear how stroke affects healthcare utilisation, medications and complications among people with diabetes. This study aimed to analyse the clinical characteristics, treatment options, medical expenses and complications of hospital outpatient healthcare associated with stroke in patients with diabetes in China.Design A retrospective, multicentre, observational study.Setting Beijing Municipal Medical Insurance Database, with data from 2016 to 2018.Participants The study included patients with diabetes whose data included 2016–2018 outpatient medication records and who had Beijing medical insurance. Patients who did not have continuous prescription records for more than 2 months were excluded from the analysis. In total, 2 853 036 people with diabetes were included, and patients who had and did not have a stroke were compared.Results In our study, 19.75%–22.30% of patients with diabetes suffered from stroke between 2016 and 2018. The average annual medical cost for a patient diagnosed with diabetes is ¥9606.65, and the cost increases to ¥13 428.39 when diabetes was combined with stroke; thus, stroke increases the medical cost for patients with diabetes by 39.78% (p
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- 2024
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3. The genetic causal effect of hand grip strength on osteoporosis and falling risk: a Mendelian randomization study
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Yanhua Ma, Jingtao Qiao, Zhenxing Wang, Qi Pan, and Lixin Guo
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hand grip strength ,osteoporosis ,falling risk ,single nucleotide polymorphisms ,Mendelian randomization ,Diseases of the endocrine glands. Clinical endocrinology ,RC648-665 - Abstract
BackgroundPatients with osteoporosis (OP) are often associated with decreased hand grip strength and increased risk of falling. It remains unclear whether there is a genetic causal between hand grip strength and OP, falling risk.MethodsThe Mendelian randomization study was used to investigate the genetic causal effect of low hand grip strength on total body bone mineral density (BMD) at different ages, OP, and falling risk. Genes for low hand grip strength, total body BMD at different ages, OP, and falling risk were obtained from published genome-wide association studies. Inverse variance weighted, MR‐Egger, and weighted median were applied to perform the MR analysis. The Cochran’s Q test, MR‐Egger intercept test, MR-PRESSO global test, and leave-one-out analysis were used to detect the pleiotropy or heterogeneity.ResultsThe results showed strong evidence that low hand grip strength was positively associated with OP (OR: 1.006, 95% CI: 1.003-1.010; P= 0.0001) and falling risk (OR: 1.069, 95% CI: 1.013-1.129; P= 0.0160), and could not directly affect the different ages of total body BMD (P> 0.05). There was no heterogeneity or horizontal pleiotropy in the sensitivity analysis (all P> 0.05).ConclusionThe study found a positive causal relationship between low hand grip strength and higher risk of OP and falling, which should be taken into account in the development of future prevention and screening strategies for OP and falling.
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- 2024
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4. Unraveling the propagation dynamics of radially polarized anomalous vortex beams in turbulent maritime atmospheres
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Hassan Al-Ahsab, Mingjian Cheng, Yuancong Cao, ShuaiLing Wang, Xiang Yi, and Lixin Guo
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Extended Huygens-Fresnel principle ,Multiple random phase screen ,Anomalous vortex beam ,Turbulent maritime atmosphere ,Radial polarization ,Physics ,QC1-999 - Abstract
Based on the unified theory of coherence-polarization, we utilize the extended Huygens-Fresnel principle to derive analytical expressions for the average intensity distribution of a radially polarized anomalous vortex beam (RPAVB) propagating through non-Kolmogorov maritime atmospheric turbulence. The hollow structure of the RPAVB can be sustained over long distances by manipulating the self-focusing point position, which depends on the initial beam parameters. This manipulation effectively mitigates the effect of maritime atmospheric turbulence. Additionally, the RPAVB undergoes a transition into a Gaussian form at significant distances, which can be intentionally slowed down by increasing the beam order, topological charge, beam width, or reducing the turbulent strength.
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- 2024
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5. Guideline for the Management of Diabetes Mellitus in the Elderly in China (2024 Edition)
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Lixin Guo and Xinhua Xiao
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diabetes ,guidelines ,the older adults ,Geriatrics ,RC952-954.6 - Abstract
Abstract With the deepening of aging in China, the prevalence of diabetes in older people has increased noticeably, and standardized diabetes management is critical for improving clinical outcomes of diabetes in older people. In 2021, the National Center of Gerontology, Chinese Society of Geriatrics, and Diabetes Professional Committee of Chinese Aging Well Association organized experts to write the first guideline for diabetes diagnosis and treatment in older people in China, the Guideline for the Management of Diabetes Mellitus in the Elderly in China (2021 Edition). The guideline emphasizes that older patients with diabetes are a highly heterogeneous group requiring comprehensive assessment and stratified and individualized management strategies. The guideline proposes simple treatments and de‐intensified treatment strategies for older patients with diabetes. This edition of the guideline provides clinicians with practical and operable clinical guidance, thus greatly contributing to the comprehensive and full‐cycle standardized management of older patients with diabetes in China and promoting the extensive development of clinical and basic research on diabetes in older people and related fields. In the past 3 years, evidence‐based medicine for older patients with diabetes and related fields has further advanced, and new treatment concepts, drugs, and technologies have been developed. The guideline editorial committee promptly updated the first edition of the guideline and compiled the Guideline for the Management of Diabetes Mellitus in the Elderly in China (2024 Edition). More precise management paths for older patients with diabetes are proposed, for achieving continued standardization of the management of older Chinese patients with diabetes and improving their clinical outcomes.
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- 2024
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6. IPILT–OHPL: An Over-the-Horizon Propagation Loss Prediction Model Established by Incorporating Prior Information Into the LSTM–Transformer Structure
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Hanjie Ji, Lixin Guo, Jinpeng Zhang, Yiwen Wei, Xiangming Guo, Yusheng Zhang, Tianhang Nie, and Jie Feng
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Evaporation duct ,long short-term memory (LSTM) network ,over-the-horizon propagation loss (OHPL) ,prediction ,transformer ,Ocean engineering ,TC1501-1800 ,Geophysics. Cosmic physics ,QC801-809 - Abstract
The evaporation duct is a prevalent atmospheric structure in the marine lower troposphere with significant regional nonuniformity. This structure can trap radio waves inside its layer and enable them to propagate over the horizon with less loss. Therefore, accurately predicting the over-the-horizon propagation loss (OHPL) is important for optimizing the performance of radio-electronic systems. Considering the OHPL characteristics in nonuniform evaporation ducts, this article establishes an OHPL prediction model by incorporating prior information into the long short-term memory (LSTM)–transformer structure (IPILT–OHPL). The combination of the LSTM network and transformer is used to construct the LSTM–transformer, aimed at leveraging their respective strengths to extract important features of OHPL effectively. In addition, to improve the prediction accuracy, this article incorporates the evaporation duct height as an environmental prior information into the LSTM–transformer. Finally, this article comprehensively evaluates IPILT–OHPL model performance in different application scenarios. The evaluation results show that the established model not only has high prediction accuracy but also strong generalization ability, which provides a new method for efficiently predicting the OHPL in nonuniform evaporation ducts.
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- 2024
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7. Research on Radar Target Detection Based on the Electromagnetic Scattering Imaging Algorithm and the YOLO Network
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Guangbin Guo, Rui Wang, and Lixin Guo
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radar imaging ,time-domain electromagnetic scattering ,YOLOv3 network ,attention mechanism ,Science - Abstract
In this paper, the radar imaging technology based on the time-domain (TD) electromagnetic scattering algorithm is used to generate image datasets quickly and apply them to target detection research. Considering that radar images are different from optical images, this paper proposes an improved strategy for the traditional You Only Look Once (YOLO)v3 network to improve target detection accuracy on radar images. The speckle noise in radar images can cover the real information of a target image and increase the difficulty of target detection. The attention mechanisms are added to the traditional YOLOv3 network to strengthen the weight of the target region. By comparing the target detection accuracy under different attention mechanisms, an attention module with higher detection accuracy is obtained. The validity of the proposed detection network is verified on a simulation dataset, a measured real dataset, and a mixed dataset. This paper is about an interdisciplinary study of computational electromagnetics, remote sensing, and artificial intelligence. Experiments verify that the proposed composite network has better detection performance.
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- 2024
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8. AFMSFFNet: An Anchor-Free-Based Feature Fusion Model for Ship Detection
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Yuxin Zhang, Chunlei Dong, Lixin Guo, Xiao Meng, Yue Liu, and Qihao Wei
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anchor free ,feature pyramid fusion ,ship detection ,SAR image ,Science - Abstract
This paper aims to improve a small-scale object detection model to achieve detection accuracy matching or even surpassing that of complex models. Efforts are made in the module design phase to minimize parameter count as much as possible, thereby providing the potential for rapid detection of maritime targets. Here, this paper introduces an innovative Anchor-Free-based Multi-Scale Feature Fusion Network (AFMSFFNet), which improves the problems of missed detection and false positives, particularly in inshore or small target scenarios. Leveraging the YOLOX tiny as the foundational architecture, our proposed AFMSFFNet incorporates a novel Adaptive Bidirectional Fusion Pyramid Network (AB-FPN) for efficient multi-scale feature fusion, enhancing the saliency representation of targets and reducing interference from complex backgrounds. Simultaneously, the designed Multi-Scale Global Attention Detection Head (MGAHead) utilizes a larger receptive field to learn object features, generating high-quality reconstructed features for enhanced semantic information integration. Extensive experiments conducted on publicly available Synthetic Aperture Radar (SAR) image ship datasets demonstrate that AFMSFFNet outperforms the traditional baseline models in detection performance. The results indicate an improvement of 2.32% in detection accuracy compared to the YOLOX tiny model. Additionally, AFMSFFNet achieves a Frames Per Second (FPS) of 78.26 in SSDD, showcasing superior efficiency compared to the well-established performance networks, such as faster R-CNN and CenterNet, with efficiency improvement ranging from 4.7 to 6.7 times. This research provides a valuable solution for efficient ship detection in complex backgrounds, demonstrating the efficacy of AFMSFFNet through quantitative improvements in accuracy and efficiency compared to existing models.
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- 2024
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9. Effects of Aluminum/Carbon and Morphology on Optical Characteristics and Radiative Forcing of Alumina Clusters Emitted by Solid Rockets in the Stratosphere
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Yueyuan Xu, Lu Bai, Jingyu Bai, and Lixin Guo
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radiative forcing ,Al2O3 clusters ,optical characteristic ,solid rocket ,Meteorology. Climatology ,QC851-999 - Abstract
Alumina (Al2O3) particles, the primary combustion products of solid rockets, can accumulate in the stratosphere, changing the global radiative balance. These Al2O3 particles were usually treated as homogeneous spheres. However, they contain impurities and may form clusters during the combustion process. Models representing Al-containing and C-containing Al2O3 clusters were developed, denoted as Al2O3 shell model (ASM) and Al2O3 core model (ACM), respectively. The superposition T-matrix method (STMM) was applied to examine their optical characteristics. Subsequently, a method to obtain the top-of-atmosphere flux was proposed by integrating the models with the moderate resolution atmospheric transmission code (MODTRAN). With the addition of Al/C, the absorption cross-section enhances by several orders of magnitude at 0.55 μm and increases slightly at 10 μm. The equivalent sphere models will weaken their scattering ability. A 4Tg mass burden of Al2O3 produces radiative forcing of −0.439 Wm−2. However, the addition of Al and C reduces the forcing by up to 15% and 12%, respectively. In summary, the optical characteristics and radiative forcing of Al2O3 clusters are sensitive to Al/C and morphology models. While our findings are impacted by various uncertainties, they contribute valuable insights into the radiative forcing of Al2O3 particles, potential climatic changes by space activities.
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- 2024
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10. Evaluating the long-term cost-effectiveness of fixed-ratio combination insulin degludec/liraglutide (IDegLira) versus other treatment regimens in the chinese type 2 diabetes patients
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Ran Wei, Weihao Wang, Xiusheng Huang, Jingtao Qiao, Jinghe Huang, Chang Xing, Qi Pan, and Lixin Guo
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Cost-effectiveness ,IDegLira ,China ,Type 2 diabetes ,Nutritional diseases. Deficiency diseases ,RC620-627 - Abstract
Abstract Background and aims To assess the cost-effectiveness of utilizing IDegLira in comparison to other treatment regimens ( liraglutide and degludec) in managing type 2 diabetes, taking into account the Chinese healthcare system’s perspective. Methods The clinical data were obtained from the randomized controlled trials (RCTs) of the DUAL I and DUAL II evidence studies that took place in China. To estimate the lifetime quality-adjusted life-years (QALYs) and direct medical costs of patients receiving different treatment strategies from a long-term perspective, the IQVIA CORE Diabetes Model version 9.0 (IQVIA, Basel, Switzerland) was utilized. The costs were evaluated from the perspective of the China National Health System. Future costs and clinical benefits were discounted annually at 5%, and sensitivity analyses were conducted. Results IDegLira was projected to reduce the incidence of diabetes-related complications and improve quality-adjusted life expectancy (QALE) versus liraglutide and degludec. A survival benefit was observed with IDegLira over Liraglutide (0.073 years). Lifetime costs were lower by Chinese yuan (CNY) 27,945 on IDegLira than on Liraglutide therapy. A similar survival benefit was observed with IDegLira over degludec (0.068 years). Lifetime costs were lower by CNY 1196 on IDegLira than on degludec therapy. Therefore, IDegLira was found to be cost-effective versus liraglutide and degludec with incremental cost-effectiveness ratios of Dominant per QALY gained, respectively, under the threshold of three times the gross domestic product (GDP) per capita in China. Conclusion IDegLira is a cost-effective hypoglycemic treatment option that delivers positive clinical outcomes while also reducing costs for Chinese patients living with type 2 diabetes.
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- 2023
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11. Prevalence of diabetic retinopathy and vision-threatening diabetic retinopathy in adults with diabetes in China
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Xuhong Hou, Limin Wang, Dalong Zhu, Lixin Guo, Jianping Weng, Mei Zhang, Zhiguang Zhou, Dajin Zou, Qiuhe Ji, Xiaohui Guo, Qiang Wu, Siyu Chen, Rong Yu, Hongli Chen, Zhengjing Huang, Xiao Zhang, Jiarui Wu, Jing Wu, Weiping Jia, and for the China National Diabetic Chronic Complications (DiaChronic) Study Group
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Science - Abstract
Abstract The current epidemic status of diabetic retinopathy in China is unclear. A national prevalence survey of diabetic complications was conducted. 50,564 participants with gradable non-mydriatic fundus photographs were enrolled. The prevalence rates (95% confidence intervals) of diabetic retinopathy and vision-threatening diabetic retinopathy were 16.3% (15.3%–17.2%) and 3.2% (2.9%–3.5%), significantly higher in the northern than in the southern regions. The differences in prevalence between those who had not attained a given metabolic goal and those who had were more pronounced for Hemoglobin A1c than for blood pressure and low-density lipoprotein cholesterol. The participants with vision-threatening diabetic retinopathy had significantly higher proportions of visual impairment and blindness than those with non-vision-threatening diabetic retinopathy. The likelihoods of diabetic retinopathy and vision-threatening diabetic retinopathy were also associated with education levels, household income, and multiple dietary intakes. Here, we show multi-level factors associated with the presence and the severity of diabetic retinopathy.
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- 2023
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12. A multicentre, prospective, non-interventional study evaluating the safety of dapagliflozin in patients with type 2 diabetes in routine clinical practice in China (DONATE)
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Lixin Guo, Jing Wang, Li Li, Lin Yuan, Sheng Chen, Hui Wang, Tonghuan Li, Lin Qi, and Hong Yang
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Chinese ,Dapagliflozin ,Genital tract infection ,Hypoglycaemia ,Non-interventional study ,Real world ,Medicine - Abstract
Abstract Background There are few large-scale studies evaluating the safety of the sodium-glucose cotransporter-2 inhibitor, dapagliflozin, in Chinese patients with type 2 diabetes. DONATE, a multicentre, single-arm, prospective, non-interventional study, is the first real-world study evaluating the safety of dapagliflozin in Chinese patients with type 2 diabetes in routine clinical practice. Methods Between August 2017 and July 2020, patients with type 2 diabetes who had initiated dapagliflozin therapy and received ≥1 dose were prospectively recruited from 88 hospitals in China. Patients were subsequently followed up for 24 weeks; if patients discontinued dapagliflozin they were followed up for an additional 7 days after treatment discontinuation. The primary outcome was the proportion of patients with adverse events and serious adverse events, particularly key adverse events of special interest (AESI) including urinary tract infection, genital tract infection (typical symptoms with or without microbiological diagnosis) and hypoglycaemia (typical symptoms with or without blood glucose ≤3.9 mmol/L, or blood glucose ≤3.9 mmol/L without symptoms). Exploratory outcomes included the absolute change in metabolic parameters and the proportion of patients with other AESI including volume depletion, abnormal blood electrolytes, polyuria, renal impairment, diabetic ketoacidosis, hepatic impairment and haematuria. Results A total of 3000 patients were enrolled, of whom 2990 (99.7%) were included in the safety analysis set. Mean (SD) age was 52.6 (12.0) years, and 65.8% of patients were male. Mean (SD) duration of type 2 diabetes at enrolment was 8.4 (7.1) years. Mean (SD) treatment duration of dapagliflozin was 209.1 (157.6) days. Adverse events were reported in 35.4% (n = 1059) of patients during the 24-week follow-up period. Overall, 9.0% (n = 268) were related to treatment and 6.2% (n = 186) were serious. Urinary tract infection, genital tract infection and hypoglycaemia were reported in 2.3% (n = 70), 1.3% (n = 39) and 1.1% (n = 32) of patients, respectively. The proportion of patients with other AESI was also low: polyuria (0.7%; n = 21), volume depletion (0.3%; n = 9), renal impairment (0.3%; n = 8), hepatic impairment (0.2%; n = 7), haematuria (0.2%; n = 6) and diabetic ketoacidosis (0.1%; n = 2). Conclusions This study demonstrated that once-daily dapagliflozin was well tolerated in Chinese patients with type 2 diabetes and the overall safety profile of dapagliflozin in clinical practice in China was consistent with that reported in clinical trials. Trial registration ClinicalTrials.gov, NCT03156985. Registered on 16 May, 2017.
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- 2023
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13. Research on the Extraction Algorithm of Dielectric Parameters of Simple Building
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Zhongyu Liu, Yuanxi Wang, Lixin Guo, Zhigang Zhong, Zuoyong Nan, Lingfeng Shen, and Jiangting Li
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Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 ,Cellular telephone services industry. Wireless telephone industry ,HE9713-9715 - Abstract
The aim of this study is to accurately extract the dielectric parameters of building materials through nondestructive measurement methods. The ultrawideband (UWB) measurement system is used to capture echoes from marble targets in the frequency range of 2.5–15 GHz, and the reflection coefficient is derived using a time window separation technique. By combining the particle swarm optimization (PSO) algorithm, the dielectric parameters of the marble targets are successfully inverted. Research results show that the relative dielectric constant extracted under three different incident angle conditions ranges from 5.370 to 5.545, and the conductivity ranges from 0.00429 to 0.00515 S/m. The root mean square error (RMSE) between the theoretically calculated reflection coefficient and the measured reflection coefficient ranges from 0.013 to 0.025, while the RMSE ranges from 0.047 to 0.066 if the dielectric parameters recommended by ITU-R P.2040-3 are used, thus confirming the accuracy and reliability of the proposed method for dielectric parameters extraction.
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- 2024
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14. Composite Electromagnetic Scattering Characteristics of Actual Terrain and Moving Rockets
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Guanhongye Peng, Xincheng Ren, Lixin Guo, Xiaomin Zhu, Pengju Yang, Ye Zhao, Bohang Zhang, and Guoshan Wu
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Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 ,Cellular telephone services industry. Wireless telephone industry ,HE9713-9715 - Abstract
This research involved studying the characteristics of composite electromagnetic scattering from a rocket moving above actual terrain using the finite-difference time-domain method. The angular distribution curve of the composite scattering coefficient was obtained, and the influences of factors such as the angle of incidence, the frequency of the incident electromagnetic wave, the content of moisture in soil, the dielectric constant of the rocket-shell material, the height of the rocket, and the undulation of the terrain on the composite scattering coefficient were investigated. Results show that the composite scattering coefficient oscillates with the scattering angle and increases in the direction of mirror reflection. It also decreases with increasing angle of incidence, frequency of the incident wave, and altitude of the rocket, while it increases with increasing soil moisture and dielectric constant of the rocket-shell materials. Although the influence of different terrain undulations on the composite scattering coefficient is noticeable, it follows no fixed pattern.
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- 2024
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15. Wireless Channel Model Based on Ray Tracing Algorithm in the Sea Environment
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Zhongyu Liu, Qi Yao, Quanqing Li, Lixin Guo, and Shuo Hu
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Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 ,Cellular telephone services industry. Wireless telephone industry ,HE9713-9715 - Abstract
The maritime environment is complex and changeable, and an accurate maritime wireless channel model is particularly difficult to establish. This study investigates the sensitivity of a three-dimensional (3D) maritime ray tracing (RT) model for the use of the geometrical optics in radio channel characterizations of maritime environments. The channel measurement experiments are mainly carried out at three frequency points of 1.5, 1.8, and 2.5 GHz, and the simulation results of the model are compared and corrected with the measured received power. Analysis shows that the modified model simulation results at 1.5, 1.8, and 2.5 GHz frequency points are in good agreement with the actual measurement, and the RMS is within 7 dB. Moreover, the reverse RT algorithm has the advantages of fast calculation speed and high efficiency. The effects of the different sea conditions, frequencies, and distances on the propagation of electromagnetic waves are analyzed on the basis of this model.
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- 2024
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16. Corrigendum: Screening and identification of hub genes in the development of early diabetic kidney disease based on weighted gene co-expression network analysis
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Ran Wei, Jingtao Qiao, Di Cui, Qi Pan, and Lixin Guo
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bioinformatics ,WGCNA ,GSEA analysis ,early diabetic kidney disease ,hub gene ,Diseases of the endocrine glands. Clinical endocrinology ,RC648-665 - Published
- 2024
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17. A new, alternative risk score for sarcopenia in Chinese patients with type 2 diabetes mellitus
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Qinghua He, Xiuzhi Wang, Caizhe Yang, Xiaoming Zhuang, Yanfen Yue, Hongjiang Jing, Jing Hu, Mingxiao Sun, and Lixin Guo
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Sarcopenia ,Type 2 diabetes ,Risk score ,Medicine - Abstract
Abstract Objective To develop a new, alternative sarcopenia risk score to screen for sarcopenia in type 2 diabetes patients in China and to demonstrate its validity. Research design and methods The data for this study came from a multicenter, cross-sectional study that had been designed to estimate the prevalence of sarcopenia among adults with type 2 diabetes and had been conducted in several hospitals in Beijing, China. A total of 1125 participants were randomly divided into two groups: an exploratory population and a validation population. A multivariable logistic regression model using the backward stepwise likelihood ratio method to estimate the probability of sarcopenia was fitted with candidate variables in the exploratory population. A new, alternative sarcopenia risk score was developed based on the multivariable model. The internal and external validations were performed in the exploratory and validation populations. The study was registered at Chinese Clinical Trial Registry (ChiCTR-EOC-15006901). Results The new, alternative sarcopenia risk score included five variables: age, gender, BMI, total energy intake per day, and the proportion of calories supplied by protein. The score ranged from − 2 to 19. The area under the receiver operating characteristic (ROC) curve of the risk score for the prediction of sarcopenia in type 2 diabetes patients was 0.806 (95% CI 0.741–0.872) and 0.836 (95% CI 0.781–0.892) in the exploratory and validation populations, respectively. At the optimal cutoff value of 12, the sensitivity and specificity of the score for the prediction of sarcopenia were 70.9% and 81.0% in the exploratory population and 53.7% and 88.8% in the validation population, respectively. The Hosmer–Lemeshow goodness-of-fit test showed a good calibration with the risk score in external validation (χ 2 = 4.459, P = 0.813). Conclusions The new, alternative sarcopenia risk score appears to be an effective screening tool for identification of sarcopenia in Chinese patients with type 2 diabetes in clinical practice. Clinical trial registration Chinese Clinical Trial Registry, ChiCTR-EOC-15006901.
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- 2023
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18. Novel properties of vacancy-ordered perovskite-Cs2BCl6 induced by d-orbital electrons
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Siyu Zhang, Lu Wang, Yujia Guo, Jie Su, Haidong Yuan, Zhenhua Lin, Lixin Guo, Yue Hao, and Jingjing Chang
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Transition metal elements ,Vacancy-ordered perovskite ,Intermediate band ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
The all-inorganic lead-free vacancy-ordered perovskite offers a promising avenue toward nontoxic and stable optoelectronic materials. Herein, we present a first-principles study of the structural stability, optical absorption, electronic structure, and mechanical behavior of Cs2BCl6 compounds with B-site substitutions (BGe, Sn, Pb, Cr, Mo, W, Ti, Zr, and Hf). The structural analysis shows that the Cs2BCl6 perovskite with face-centered cubes has a stable chemical environment, especially Cs2HfCl6, Cs2WCl6, and Cs2PbCl6. Hf4+ and W4+ with high-energy d-state external electron configurations can further lower the valence band maximum position of the Cs2BCl6 structures and thus increase the band gap, assisting in tuning the optical absorption and emission properties of these structures in the optoelectronic application. For the light absorption properties of Cs2BCl6 materials, the best light absorption properties have been concluded for Ti4+, Cr4+, and Pb4+-based perovskite in the visible range due to a suitable band gap. Therefore, the excellent optical absorption and electronic properties make these vacancy-ordered perovskites promising candidates for optoelectronic applications.
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- 2025
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19. Electromagnetic scattering characteristics of a hypersonic vehicle with a microrough surface in the millimeter wave band
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Haifeng Zhang, Jiangting Li, Changkui Qiu, Zhefeng Yu, Zheng Bian, Lixin Guo, Linjing Guo, and Songhua Liu
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Physics ,QC1-999 - Abstract
The rough structure may affect the flow field and electromagnetic (EM) scattering characteristics of a hypersonic vehicle. In this study, the EM scattering characteristics of the hypersonic vehicle RAM C-II with a microrough surface were investigated in the millimeter wave band. We first simulated the flow field of a smooth RAM C-II vehicle and calculated the radar cross section (RCS) in the wideband using the physical optics method. The calculation results show that many factors contribute to the variation in the RCS; however, it is occasionally difficult to predict. We then used a one-dimensional Gaussian random rough surface to generate a RAM C-II with a microrough surface through a point-coordinate transformation and simulated its flow field. The electron density flow field of the rough surfaced aircraft fluctuates greatly on the wall. Finally, we calculated the RCS of RAM C-II with different values of roughness in the millimeter wave band. The change of surface structure can be reflected in millimeter waves, and the RCS is determined by both plasma and rough structure.
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- 2023
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20. Status and Prospects of Electromagnetic Scattering Echoes Simulation from Complex Dynamic Sea Surfaces and Targets
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Lixin GUO and Yiwen WEI
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em scattering ,sea clutter ,sea echo analysis ,sar imaging ,target detection and recognition ,Electricity and magnetism ,QC501-766 - Abstract
The ocean surface is a complicated dynamic system with considerable irregularity and nonrepetition in space and time. Sea clutter is the superposition of a large number of scatterer echoes generated by the radar electromagnetic signal irradiated to the sea surface, which is affected by wind, currents, waves, etc. and shows nonuniformity and nonsmoothness. The sea clutter signal has a certain interference effect on the detection of sea targets, especially under high sea conditions when the waves are furious, and the target signal is readily drowned out by the strong sea clutter signal, severely limiting the radar’s detection capability on sea targets. The investigation of sea clutter and target electromagnetic scattering properties serves as the foundation for improving the target detection capability in difficult marine environments. The formation of target echo data in the actual marine environment is of great significance for the analysis of sea clutter and target radar echo characteristics, as well as the supplementation of the actual measurement data set based on electromagnetic waves and the actual complex dynamic sea surface and target electromagnetic scattering mechanism. This study summarizes three key categories of echo simulation methods, analyzes the benefits, disadvantages, and adaptability of several categories of methods for the characteristics of the sea surface and target simulation scenarios, and provides some simulation results in order to make recent advancements and future trends of physics-based complex sea environment and target echo simulation methods more accessible to relevant researchers. It also introduces some echo datasets based on real measurements, which can facilitate scholars’ analysis of echo characteristics. Lastly, the trend toward developing complex sea surface and target echo simulation methods and characteristics for research is presented.
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- 2023
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21. Physical Activity, Sedentary Behavior, and the Risk of Cardiovascular Disease in Type 2 Diabetes Mellitus Patients: The MIDiab Study
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Yafei Wu, Guijun Qin, Guixia Wang, Libin Liu, Bing Chen, Qingbo Guan, Zhongshang Yuan, Xu Hou, Ling Gao, Chao Xu, Haiqing Zhang, Xu Zhang, Qiu Li, Yongfeng Song, Fei Jing, Shizhan Ma, Shanshan Shao, Meng Zhao, Qingling Guo, Nanwei Tong, Hongyan Zhao, Xiaomin Xie, Chao Liu, Zhongyan Shan, Zhifeng Cheng, Xuefeng Yu, Shulin Chen, Tao Yang, Yangang Wang, Dongmei Li, Zhaoli Yan, Lixin Guo, Qiuhe Ji, Wenjuan Wang, and Jiajun Zhao
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Type 2 diabetes ,Physical activity ,Sedentary time ,Cardiovascular disease ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
The aim of this study was to explore the associations of moderate-to-vigorous-intensity physical activity (MVPA) time and sedentary (SED) time with a history of cardiovascular disease (CVD) and multifactorial (i.e., blood pressure (BP), body mass index (BMI), low-density lipoprotein cholesterol (LDL-C), and glycated hemoglobin A1c (HbA1c)) control status among type 2 diabetes mellitus (T2DM) patients in China. A cross-sectional analysis of 9152 people with type 2 diabetes from the Multifactorial Intervention on Type 2 Diabetes (MIDiab) study was performed. Patients were grouped according to their self-reported MVPA time (low, < 150 min·week−1; moderate, 150 to < 450 min·week−1; high, ≥ 450 min·week−1) and SED time (low, < 4 h·d–1; moderate, 4 to < 8 h·d–1; high, ≥ 8 h·d–1). Participants who self-reported a history of CVD were identified as having a CVD risk. Odds ratios (ORs) and 95% confidence intervals (CIs) of CVD risk and multifactorial control status associated with MVPA time and SED time were estimated using mixed-effect logistic regression models, adjusting for China’s geographical region characteristics. The participants had a mean ± standard deviation (SD) age of (60.87 ± 8.44) years, 44.5% were women, and 25.1% had CVD. After adjustment for potential confounding factors, an inverse association between high MVPA time and CVD risk that was independent of SED time was found, whereas this association was not observed in the moderate-MVPA group. A higher MVPA time was more likely to have a positive effect on the control of BMI. Compared with the reference group (i.e., those with MVPA time ≥ 450 min·week−1 and SED time
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- 2023
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22. Beneficial effect of time-restricted eating on blood pressure: a systematic meta-analysis and meta-regression analysis
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Weihao Wang, Ran Wei, Qi Pan, and Lixin Guo
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Time-restricted eating ,Blood pressure ,Meta-analysis ,Nutrition. Foods and food supply ,TX341-641 ,Nutritional diseases. Deficiency diseases ,RC620-627 - Abstract
Abstract Background As a cardiometabolic disease, hypertension has shown an obvious upward trend, becoming a global epidemic chronic disease. Lifestyle intervention is a fundamental method for lowering blood pressure. This systematic review and meta-analysis aimed to evaluate the effects of time-restricted eating (TRE) on blood pressure. Methods Studies were retrieved from the PubMed, Embase, Cochrane Library, and Web of Science databases to evaluate the effects of TRE on blood pressure. The time frame of search was from the start of database construction until July 14, 2022.There were no language restrictions. Meta-analysis and meta-regression were performed using Stata version 16. The weighted mean difference with 95% CI was used to assess the effect of TRE on blood pressure, heart rate, weight, blood glucose, total cholesterol, HDL-C, LDL-C, and triglycerides. The main ending of this article were blood pressure and heart rate, while the secondary ending were weight, blood glucose, total cholesterol, HDL-C, LDL-C, and triglycerides. Results Ten randomized controlled trials involving 694 patients were identified. TRE significantly reduced systolic blood pressure (SBP) (mean difference = −4.15; 95% CI: −6.73, −2.30; P < 0.0001), but had no significant effect on diastolic blood pressure (DBP) (mean difference = −2.06; 95% CI: −4.16, 0.02; P = 0.053) and no beneficial effect on heart rate (mean difference = 0.36; 95% CI: −2.83, 3.54; P = 0.0825). TRE promoted weight loss (mean difference = −1.63; 95% CI: −2.61, −0.64; P = 0.001) and decreased blood glucose levels (mean difference = −2.80; 95% CI: −4.64, −0.96; P = 0.003), but had no significant effect on total cholesterol (mean difference = 0.03, 95% CI: −10.01, 10.08; P = 0.995), HDL-C (mean difference = 0.85, 95% CI: −1.80, 3.49; P = 0.531), LDL-C (mean difference = −0.86, 95% CI: −6.47, 4.76; P = 0.764), or triglycerides (mean difference = −3.524, 95% CI: −9.49, 2.45; P = 0.248). In a separate meta-regression analysis, the degree of SBP change was related to weight loss (P = 0.044) but not to glucose improvement (P = 0.867). Conclusions The present meta-analysis suggests that TRE significantly reduced SBP, while no effect of reducing DBP was seen. The observed lower blood pressure may be attributed to significant weight loss. The effects of TRE on heart rate and blood lipid levels were not apparent.
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- 2022
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23. Prevalence of obstructive sleep apnea syndrome in hospitalized patients with type 2 diabetes in Beijing, China
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Shan Ding, Puhong Zhang, Li Wang, Du Wang, Kaige Sun, Yahui Ma, Hongbing Wang, Chun Xu, Rui Zhang, Xianbo Zhang, Hongyu Wang, Fang Zhao, Xian Li, Linong Ji, and Lixin Guo
- Subjects
Obstructive sleep apnea ,Prevalence ,Type 2 diabetes ,Diseases of the endocrine glands. Clinical endocrinology ,RC648-665 - Abstract
Abstract Aims/Introduction To estimate the prevalence, and patient clinical and demographic profile, as well as risk factors associated with obstructive sleep apnea syndrome (OSAS) in hospitalized patients with type 2 diabetes mellitus in Beijing, China. Materials and Methods Hospitalized adult patients with type 2 diabetes mellitus were consecutively screened and invited for an overnight polysomnography from four hospitals in Beijing, China, from May 2016 to February 2017. We used the American Academy of Sleep Medicine 2012 polysomnography recording techniques and scoring criteria to identify the type of apnea and the severity of OSAS. The χ2‐test was used to evaluate differences between groups regarding the prevalence, and demographic and other clinical parameters. Results A total of 735 patients were found eligible for the study, of whom 309 patients completed the overnight polysomnography. The mean age of the patients was 58.2 ± 10.9 years, and most (67.3%) were men. The prevalence of overall (apnea hypopnea index ≥5/h), moderate‐to‐severe (apnea hypopnea index ≥15/h) and severe (apnea hypopnea index ≥30/h) OSAS was 66.3% (95% confidence interval 60.8–71.6%), 35.6% (95% confidence interval 30.3–41.2%) and 16.5% (95% confidence interval 12.5–21.1%), respectively. Central and mixed apnea contributed 12% to all sleep‐disordered breathing. With the aggravation of OSAS, the combined prevalence for central, mixed and obstructive apnea increased from 57% to 70%. We found OSAS to be associated with older age, obesity, self‐reported snoring and apnea, and diabetes complications. Conclusions Guidelines on screening and treatment of OSAS among hospitalized patients with diabetes are needed to direct the routine practice for diabetes endocrinologists for optimal clinical care of such patients.
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- 2022
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24. Design of a point-focusing lens antenna based on 3D printing for a small-area plasma
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Dong Yue, Lixin Guo, Jiangting Li, and Linjing Guo
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Physics ,QC1-999 - Abstract
The interaction mechanism between plasmas and electromagnetic waves has not been fully defined, and experiments are helpful for investigating the mechanism and verifying the theoretical analysis. This paper proposes a point-focusing lens antenna based on three-dimensional (3D) printing technology for the experimental study of the interaction between electromagnetic waves and a small-area plasma. First, CST simulation software was used for the simulation design of the horn antenna and focusing lens. Subsequently, 3D printing technology was used to print the lens combined with the horn antenna for experimental verification of the focusing performance. Finally, an electromagnetic wave passing through a plasma was experimentally investigated, and it was mutually verified with the propagation theory of electromagnetic waves in plasmas. The experimental and theoretical data indicated that the 3D-printed point-focusing lens antenna exhibited a good focusing effect on electromagnetic waves. This method may be used by employing a variety of materials and designs, thereby considerably improving the detection of small-area plasma. It may also solve the issue of the radial diffraction effect of narrow cylindrical plasma generated by inductively coupled plasma-generation equipment and reduce the error associated with experimental data. Therefore, this method may be useful for plasma propagation measurement, plasma-environment diffraction analysis, and parameter inversion of complex plasma environments.
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- 2023
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25. Propagation behavior of orbital angular momentum in vector anomalous vortex beams under maritime atmospheric turbulence
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Hassan T. Al-Ahsab, Qi Cheng, Mingjian Cheng, Lixin Guo, Yuancong Cao, and ShuaiLing Wang
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orbital angular momentum ,anomalous vortex beam ,maritime atmospheric turbulence ,detection probability ,Rytov approximation ,Physics ,QC1-999 - Abstract
This study explores the propagation properties of orbital angular momentum (OAM) carried by a vector anomalous vortex beam (VAVB) in maritime atmospheric turbulence, utilizing the Rytov approximation. A comparative analysis is conducted between the VAVB and Laguerre-Gaussian beam, revealing that the VAVB exhibits a higher detection probability under specific circumstances. This suggests that the VAVB is more suitable for scenarios where maximizing detection probability is critical. The detection probability of the signal OAM mode is affected by the characteristics of maritime atmospheric turbulence and propagation distance, but can be significantly improved by manipulating beam parameters such as wavelength, beam order, beam waist, and quantum number, while considering the characteristics of maritime atmospheric turbulence. Hence, the use of VAVB has the potential to facilitate reliable optical communication in challenging maritime environments.
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- 2023
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26. Pharmacokinetics, pharmacodynamics, and safety of prandial oral insulin (N11005) in healthy subjects
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Qi Pan, Xiaoxia Wang, Wenjia Li, Xiaofeng Chen, Yulei Zhuang, Qinghong Zhou, Yuhui Huang, Yijie Zhou, Li Lan, Zhijie Wang, Wenjia Wang, Juan Hong, Wei-Hua Hao, Yu-Tsai Yang, and Lixin Guo
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oral insulin ,pharmacokinetics ,pharmacodynamics ,safety ,healthy subjects ,Diseases of the endocrine glands. Clinical endocrinology ,RC648-665 - Abstract
AimsTo verify whether the oral insulin N11005 is administered as a prandial insulin by assessing the pharmacokinetics (PK), pharmacodynamics (PD), and safety profiles of N11005 with a short-acting biosynthetic human insulin (Novolin R) as reference.MethodsThis was a randomized, open-label, single-dose, crossover hyperinsulinemic-euglycemic clamp study in healthy Chinese male subjects. A total of 12 subjects were enrolled in the test (T) group (N11005, 300 IU, p.o.) and the reference (R) group (Novolin R, 0.1 IU/Kg, i.h.) with a washout period of 14 days. All subjects were administered on the same day of the clamp study. Glucose Infusion Rates (GIR), serum insulin, and C-peptide concentration were determined during every 8-hour clamp cycle. Trial registration: Clinicaltrials.gov identifier NCT04975022.ResultsAfter administration, the ratios of mean serum C-peptide concentration to baseline concentration in both T and R groups were lower than 50%, which confirmed the stability of the clamp platform. T group (N11005) showed a more rapid onset of action (tGIR10%max≈11 min) and a comparable duration of action to the R group, which was basically in line with the characteristics of prandial insulins. No adverse events (AEs) occurred throughout the study, which demonstrated that N11005 and Novolin R are safe and well-tolerated.ConclusionsThe PD profiles of the single-dose N11005 in the human body are similar to those of prandial insulins, with an excellent safety profile.Clinical trial registrationClinicaltrials.gov, identifier NCT04975022.
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- 2023
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27. A self-controlled, cross-over study of intensive insulin treatment with needle-based injection versus needle-free injection in hospitalized patients with type 2 diabetes
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Quanying Wu, Mingqun Deng, Weihao Wang, Shuyi Yu, Miao Wang, Chao Sun, Qi Pan, and Lixin Guo
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needle-free injection ,diabetes ,intensive insulin therapy ,in hospital ,cross-over study ,Diseases of the endocrine glands. Clinical endocrinology ,RC648-665 - Abstract
Background and AimsNeedle injection and needle-free injection were proven effective in improving glycated hemoglobin (HbA1c) in type 2 diabetes mellitus (T2DM) patients. However, it is unclear if needle-free and needle injections of insulin during intensive insulin therapy in hospitalized patients provide similar efficacy and safety benefits.MethodsA self-controlled cross-over study was conducted on 62 patients with T2DM who received intensive long-acting and short-acting insulin injections with or without needles. The 7-point blood glucose test was performed on the 6th day after insulin administration and the injection method switched on the 7th day of hospitalization. The difference was compared in 7-point blood glucose levels.ResultsThe blood glucose levels at fasting (mean difference=-1.09 ± 2.38mmol/L, 95% CI, -1.69 to -0.48, p=0.0007) and post-breakfast (-1.14 ± 3.02mmol/L, 95%CI, -1.91 to -0.37, p=0.004) were better when patients were receiving needle-free injections compared to when receiving a needle injection. Indeed, daily blood glucose fluctuation, which presented as the area under the curve of glycemia, was decreased in needle-free injection periods (-0.3.48 ± 9.64, 95%CI, -5.95 to -1.01, p=0.0065). There was no significant difference in the dose of long-acting insulin between the two injection methods (-0.32 ± 2.69, 95%CI, -0.99 to 0.37, p>0.05). The dose of fast-acting insulin during the needle-free period was lower than that of when patients received needle injections (-1.66 ± 6.45, 95%CI, -3.29 to -0.025, p
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- 2023
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28. Scattering Field Intensity and Orbital Angular Momentum Spectral Distribution of Vortex Electromagnetic Beams Scattered by Electrically Large Targets Comprising Different Materials
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Minghao Sun, Songhua Liu, and Lixin Guo
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angular spectral decomposition ,electrically large target ,orbital angular momentum spectra ,physical optics ,scattering field ,vortex electromagnetic beam ,Science - Abstract
In this study, we obtained the intensity and orbital angular momentum (OAM) spectral distribution of the scattering fields of vortex electromagnetic beams illuminating electrically large targets composed of different materials. We used the angular spectral decomposition method to decompose a vortex beam into plane waves in the spectral domain at different elevations and azimuths. We combined this method with the physical optics algorithm to calculate the scattering field distribution. The OAM spectra of the scattering field along different observation radii were analyzed using the spiral spectrum expansion method. The numerical results indicate that for beams with different parameters (such as polarization, topological charge, half-cone angle, and frequency) and targets with different characteristics (such as composition), the scattering field intensity distribution and OAM spectral characteristics varied considerably. When the beam parameters change, the results of scattering from different materials show similar changing trends. Compared with beams scattered by uncoated metal and dielectric targets, the scattering field of the coating target can better maintain the shape and OAM mode of beams from the incident field. The scattering characteristics of metal targets were the most sensitive to beam-parameter changes. The relationship between the beam parameters, target parameters, the scattering field intensity, and the OAM spectra of the scattering field was constructed, confirming that the spiral spectrum of the scattering field carries the target information. These findings can be used in remote sensing engineering to supplement existing radar imaging, laying the foundation for further identification of beam or target parameters.
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- 2024
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29. Charging Process in Dusty Plasma of Large-Size Dust Particles
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Dong Yue, Ke Li, Lixin Guo, Jiangting Li, and Yan Zheng
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dusty plasma ,charging process ,Debye radius ,electromagnetic waves ,Science - Abstract
During reentry, the high temperatures experienced by near-space hypersonic vehicles result in surface ablation, generating ablative particles. These particles become part of a plasma, commonly referred to as a “dusty plasma sheath” in radar remote sensing. The dusty plasma model, integral in radar studies, involves extensive charge and dynamic interactions among dust particles. Previous derivations assumed that the dust particle radius significantly surpassed the Debye radius, leading to the neglect of dust radius effects. This study, however, explores scenarios where the dust particle radius is not markedly smaller than the Debye radius, thereby deducing the charging process of dusty plasma. The derived equations encompass the Debye radius, charging process, surface potential, and charging frequency, particularly considering larger dust particle radii. Comparative analysis of the dusty plasma model, both before and after modification, reveals improvements when dust particles approach or exceed the Debye length. In essence, our study provides essential equations for understanding dusty plasma under realistic conditions, offering potential advancements in predicting electromagnetic properties and behaviors, especially in scenarios where dust particles closely align with or surpass the Debye radius.
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- 2024
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30. Research on the Ionospheric Delay of Long-Range Short-Wave Propagation Based on a Regression Analysis
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Xiaoli Jiang, Huimin Li, Lixin Guo, Dalin Ye, Kehu Yang, and Jiawen Li
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group delay ,phase advance ,short-wave ,regression analysis ,ray-tracing algorithm ,Science - Abstract
The ionospheric delay effect is inevitable when a radio signal propagates through the ionosphere. It has been extensively studied in the L-band. Typically, the influence of the ionosphere on the code phase and carrier phase is regarded as the same. In this study, a numerical ratio between the group delay time and phase advance time with reference to the study of the L-band is investigated in the short-wave band. The variation in the numerical ratio with frequency, critical frequency, and elevation angle is discussed in detail. There appears an interesting phenomenon wherein the elevation angle has a greater effect on the ratio than the frequency and critical frequency. The numerical ratio increases with an increasing elevation angle. On the other hand, a regression analysis is used to establish the mapping relation between the ratio and the three factors of frequency, critical frequency, and elevation angle, based on the simulation results obtained by a ray-tracing algorithm. The little relative errors between the fitted values and simulation values under different ionospheric models prove the relationship between the ratio and the three factors of frequency, critical frequency, and elevation angle.
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- 2024
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31. Fast Solution of Scattering and Micro-Doppler Features from Moving Target Using a Tailored Shooting and Bouncing Ray Method
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Yongji Xi, Juan Li, Lixin Guo, Wei Meng, and Shunkang Wen
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micro-Doppler ,moving target ,dynamic space division ,shooting and bouncing ray (SBR) ,time-frequency analysis ,Science - Abstract
In this paper, we present a tailored shooting and bouncing ray (SBR) method for the fast solution of electromagnetic (EM) scattering from a moving target. And, the micro-Doppler features of the moving target are investigated using a time-frequency analysis technique. In our method, a dynamic spatial division technique is employed to accelerate facet information processing and ray-tracing progress of the moving target. At first, the two coordinate systems are established, which are the geodetic coordinate system (GCS) and the local coordinate system (LCS). In GCS, the target is moving with translation and rotation. The dynamic spatial division is established in LCS to store the facet information and remain relatively stationary to the target. In comparison with the traditional SBR method, this technique avoids repetitive spatial division at each moment in the GCS. Then, ray tracing is performed to find the illuminated facets in the LCS. Finally, the scattering field and the phase compensation are computed in the GCS. In numerical simulations, the verification and computation efficiency comparison are provided using our method and other solutions (MLFMM, RL-GO, and traditional SBR). Moreover, the micro-Doppler features are extracted and analyzed using the time-frequency analysis technique, which includes the precession and spin of the missile, and the rotation of the aircraft. Meanwhile, the micro-Doppler spectra of the target is also compared with the theoretical Doppler of equivalent strong scattering points, which are obtained using the instantaneous high-resolution range profile (HRRP).
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- 2023
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32. How does diabetic peripheral neuropathy impact patients' burden of illness and the economy? A retrospective study in Beijing, China
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Qi Pan, Sijia Fei, Lina Zhang, Huan Chen, Jingyi Luo, Weihao Wang, Fei Xiao, and Lixin Guo
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diabetic peripheral neuropathy (DPN) ,medications ,medical costs ,burden of illness ,hypoglycemic therapy ,Public aspects of medicine ,RA1-1270 - Abstract
ObjectiveDiabetic peripheral neuropathy (DPN) causes significant illness in patients and has a negative impact on the economy. The objective of this study is to evaluate the cost and quantity of anti-diabetic drugs needed by patients with or without DPN, as well as their variation trends in Beijing between 2016 and 2018.MethodsThis observational cross-sectional study used data on diabetic patients with outpatient medication records obtained from Beijing Medical Insurance from 2016 to 2018. The medications, comorbidities, diabetes-related complications, treatment strategies, and costs of drug treatment were compared between DPN patients and non-DPN patients.ResultsOf the 28,53,036 diabetic patients included in the study, 3,75,216 (13.15%) had DPN and 1,87,710 (50.03%) of the DPN patients were women. Compared with non-DPN patients, DPN patients used more mediations (4.7 ± 2.47 vs. 3.77 ± 2.32, p < 0.0001, in 2018) to treat related complications and comorbidities (2.03 ± 1.2 vs. 1.71 ± 1.05; 2.68 ± 1.93 vs. 2.06 ± 1.86, p < 0.0001, respectively, in 2018). The total annual costs of drug treatment were higher in DPN patients than in non-DPN patients (¥12583.25 ± 10671.48 vs. ¥9810.91 ± 9234.14, p < 0.0001, in 2018). The usage of DDP4i increased from 2.55 to 6.63% in non-DPN patients and from 4.45 to 10.09% in DPN patients from 2017 to 2018.ConclusionsThe number of comorbidities, diabetic complications, medications, and annual drug treatment costs were greater in DPN patients than in non-DPN patients.
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- 2023
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33. Orbital angular momentum of Laguerre-Gaussian beams with non-zero radial index at limited aperture size
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Yankun Wang, Lu Bai, Chao Huang, Jinyu Xie, Danmeng Zhang, and Lixin Guo
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Orbital angular momentum ,Radial numbers ,LG beam ,Limited aperture ,Physics ,QC1-999 - Abstract
The study of orbital angular momentum (OAM) calculation and measurement of complex radial structure beams with limited receiving aperture size is of practical significance. In this paper, taking the Laguerre-Gaussian beam with non-zero radial index as an example, we give the calculation method of its OAM at limited aperture size and design an experiment. We theoretically and experimentally demonstrate the strong correlation between OAM and radial number and we believe that the calculation method can be extended to all local OAM calculations with complex radial structure beams.
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- 2023
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34. Analysis of Infrared Spectral Radiance of O2 1.27 μm Band Based on Space-Based Limb Detection
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Jingyu Bai, Lu Bai, Jinlu Li, Chao Huang, and Lixin Guo
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oxygen ,infrared spectral radiance ,limb detection ,spectral line selection ,Science - Abstract
The infrared spectral radiance of O2 is of great significance for space-based infrared detection. In this work, based on the demand for near-infrared spectral radiance of O2 limb detection, a method of spectral radiance calculation coupled with an atmospheric remote sensing model of limb detection is proposed. According to the selection criteria of fine spectral lines, the most suitable spectral lines of the O2 1.27 μm band for detection are given. Specifically, the limb infrared radiances of the O2 1.27 μm band were simulated by using the spectral line data from the spectral database, and the effects of molecular self-absorption were also considered. Furthermore, the infrared spectral radiance distribution of the O2 1.27 μm band was simulated under the influence of altitude, and finally, the detectability of the 1.27 μm band of O2 molecules was analyzed using the criteria of spectral line selection, radiance intensity, spectral separation range and temperature sensitivity. The calculation results show that the spectral radiance of the 1.27 μm band of O2 molecules first increases and then decreases with the decrease of the limb height, and the radiance reaches the peak value in the range of 40–50 km. In terms of the selection of spectral lines, the two groups of spectral lines R7R7, R7Q8 and R11R11, R11Q12 are most suitable for the limb detection and measurement of the O2 1.27 μm band.
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- 2023
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35. Efficacy of unblinded and blinded intermittently scanned continuous glucose monitoring for glycemic control in adults with type 1 diabetes
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Lixin Guo, Yuxiu Li, Mei Zhang, Xinhua Xiao, Hongyu Kuang, Tao Yang, Xiaofan Jia, and Xianbo Zhang
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clinical trial ,continuous glucose monitor ,sensors ,type 1 diabetes ,blinded and unblinded ,Diseases of the endocrine glands. Clinical endocrinology ,RC648-665 - Abstract
ObjectiveIntermittently scanned continuous glucose monitoring (isCGM) is used for unblinded or blinded monitoring of interstitial glucose. We aimed to compare the efficacy of blinded and unblinded isCGM with the FreeStyle Libre system for glycemic control in adults with type 1 diabetes (T1D).Research design and methodsThis randomized clinical trial conducted between October 2018 and September 2019 across four endocrinology practices in China included 273 adults aged ≥18 years with T1D, who were randomly divided in a 2:1 ratio into the unblinded (n = 199) or blinded isCGM group (n = 78). In the blinded group, the clinician used FreeStyle Libre Pro system for monitoring, but self-monitoring was also performed by the patients.ResultsTwo hundred sixteen (78%) participants completed the study (152 [75%] in the unblinded and 64 [82%] in the blinded group). At 12 weeks, a significant increase in TIR (3.9-10.0 mmol/L) was only observed in the unblinded group, along with a significant decrease in hyperglycemia (>13.9 mmol/L), hypoglycemia (
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- 2023
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36. lncRNA MELTF-AS1 facilitates osteosarcoma metastasis by modulating MMP14 expression
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Lei Ding, Taiyuan Liu, Yuan Qu, Zhichen Kang, Lixin Guo, Haina Zhang, Junjie Jiang, Fuling Qu, Wanbao Ge, and Shanyong Zhang
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MELTF-AS1 ,miR-485-5p ,MMP14 ,osteosarcoma ,tumor metastasis ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Osteosarcoma is a highly aggressive cancer common in children and adolescents. There is still a lack of effective treatments for metastatic or recurrent osteosarcoma. The role of long non-coding RNAs (lncRNAs) in osteosarcoma has gradually attracted attention. Here, we identified lncRNAs that were abnormally expressed in metastatic osteosarcoma through analyzing the sequencing data of osteosarcoma tissues and selected upregulated lncRNA MELTF-AS1 for detailed study. The qRT-PCR analysis showed that the expression of MELTF-AS1 was increased in osteosarcoma tissues and cells, and the high expression of MELTF-AS1 indicated a poor prognosis of osteosarcoma patients. The high expression of MELTF-AS1 in osteosarcoma was partly due to the transcriptional activation of RREB1. The results of transwell assays, scratch wound healing assays, and the tail vein injection lung metastasis model demonstrated that knocking down MELTF-AS1 inhibited metastasis ability of osteosarcoma cells. Furthermore, the results of RNA pull-down assays, luciferase reporter assays, and RNA immunoprecipitation (RIP) assays revealed that MELTF-AS1 could regulate MMP14 expression through interaction with miR-485-5p. Our study suggested that MELTF-AS1 functioned as a pro-metastasis gene in osteosarcoma by upregulating MMP14 and that it could be a potential therapeutic and diagnostic target for osteosarcoma.
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- 2021
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37. Influence of oral nutritional agents rich in soluble dietary fiber on intestinal flora of elderly men with malnutrition
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Dongni Yu, Mingyue Cheng, Lixin Guo, Wenli Liu, Ye Liu, Kang Ning, Yigang Tong, Xuejiao Yan, Lei Qiu, and Haimei Qi
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elderly male subjects ,intestinal flora ,malnutrition ,oral nutritional agents ,Geriatrics ,RC952-954.6 - Abstract
Abstract Objective Observe the influence of oral nutritional agents rich in soluble dietary (enteral nutritional suspension [TPF‐DM]) on intestinal flora of elderly male subjects with malnutrition. Method Seventy‐eight subjects with good nutrition were considered as the healthy control group. Twenty‐eight male subjects who had malnutrition and were older than 70 years were included and randomly divided into the short‐term (3 months) intervention group (n = 20) and the long‐term (12 months) group (n = 8). They were provided with enteral nutritional suspension (TPF‐DM) 500 mL/day or maximum tolerance dose, so as to observe the changes in nutrition‐related indexes and intestinal flora after the elderly take enteral nutritional suspension (TPF‐DM). Results (1) For elderly male subjects with malnutrition, their body weight, body mass index, hemoglobin, total protein, and albumin were significantly lower than the control group with favorable nutrition. (2) There were obvious differences in intestinal flora between healthy elderly male subjects and those with malnutrition. After the treatment of enteral nutritional suspension (TPF‐DM), intestinal flora of the malnourished elderly subjects showed recovery toward the healthy elderly subjects. The obvious gradient changes of the flora were mainly in the bacteroidetes, firmicutes, and proteobacteria phyla, and the relative abundance of CAG2 clusters in the malnourished group was higher than that in the healthy control group, and the relative abundance decreased after long‐term treatment, and the change approached the healthy control group. The relative abundance of CAG3 and CAG6 clusters in the malnourished group was lower than that in the healthy control group, and the relative abundance increased after long‐term treatment, and the change approached the healthy control group. Conclusion Malnutrition has obvious impact on intestinal flora of the elderly. Enteral nutritional suspension (TPF‐DM) not only prevents the further decline in the state of nutrition but also helps the recovery in intestinal flora of the elderly. Long‐term application can produce better effects.
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- 2021
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38. Scintillation theory of optical waves propagating through moderate to strong compressible turbulence
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Jinyu Xie, Lu Bai, Yankun Wang, and Lixin Guo
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Wave propagation ,Scintillation index ,Compressible turbulence ,Extended Rytov theory ,Physics ,QC1-999 - Abstract
Compressible turbulence around an aircraft will cause irradiance fluctuations in the optical waves in optical communication between the aircraft and the outside. Turbulence can cause signal fluctuation or even interruption, and the exploration of the issue plays an important role in aero-optics. Based on the extended Rytov theory, we develop theoretical expressions of the scintillation index for plane and spherical waves propagating in moderate to strong compressible fluctuations by a near wall compressible turbulence refractive index spectrum. The numerical results show that the derived scintillation index is in good agreement with weak fluctuation and asymptotic theory approximation. The predicted scintillation index first increases sharply with the path length and reaches a peak, after which it falls back to saturation. During weak fluctuations, the scintillation index of long wavelength waves is smaller than that of short wavelength waves, but in moderate to strong turbulence, the scintillation index of short wavelength waves has an advantage over that of long wavelength waves. Furthermore, we provide physical explanations for the scintillation index trend.
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- 2022
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39. A Random Forest Algorithm Combined with Bayesian Optimization for Atmospheric Duct Estimation
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Chao Yang, Yulu Wang, Aoxiang Zhang, Hualei Fan, and Lixin Guo
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atmospheric duct estimation ,random forest ,radar sea clutter ,parabolic equation ,orthogonal experiment design ,Science - Abstract
Inversion of atmospheric ducts is of great importance in the field of performance evaluation for radar and communication systems. Since the model parameters in machine learning play a crucial role in prediction performance, this paper develops a random forest (RF) model integrated with Bayesian optimization (BO) called BO-RF for atmospheric duct prediction, and the BO is adopted to determine appropriate model parameters during the training process. In addition, the K-fold cross-validation (CV) method is also incorporated into the model to obtain the best model partition and overcome the overfitting problem. To test the performance of the proposed model, the results obtained by the BO-RF are compared with other commonly used methods, such as classical RF, extreme gradient boosting (XGBoost) with/without BO, and K-nearest neighbor (KNN) with/without BO. Comparisons demonstrate that BO-RF has the best accuracy and anti-noise ability for the estimation of duct parameters.
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- 2023
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40. Analytical Modeling of Electromagnetic Scattering and HRRP Characteristics from the 3D Sea Surface with a Plunging Breaker
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Chunlei Dong, Xiao Meng, Jinpeng Zhang, Yue Liu, Qihao Wei, and Lixin Guo
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sea surface ,plunging breaker ,sea-spikes ,HRRP ,Science - Abstract
Electromagnetic (EM) scattering of sea surface may exhibit sea-spikespikes when there exist breaking waves. As sea-spikes are usually mistaken for targets, the investigation of EM scattering characteristics and high-range resolution profiles (HRRPs) of three-dimensional (3D) sea surfaces with a plunging breaker is meaningful for target detection and recognition. To describe the basic features of a plunging breaker, this paper developed a feasible and wind-related plunging breaker model. Here, profiles of a plunging breaker in its life cycle are modeled according to the wind speed and time factor, and the small-scale roughness is considered. Then, the sea surface and plunging breaker are combined to obtain the composite model. Additionally, a hybrid algorithm based on the Capillary Wave Modification Facet Scattering Model (CWMFSM) and ray tracing technique is developed to calculate the EM scattering of 3D sea surface with a plunging breaker. Simulation results show that the sea-spike phenomenon is more likely to occur for the upwind and large incident angles. The amplitude of the backscattering electric field from the plunging breaker is much stronger than that of the sea surface. Furthermore, the HRRPs of 3D sea surface with a plunging breaker and target are computed. Sharp peaks from the plunging breaker that exhibit obvious target-like features are observed.
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- 2023
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41. Editorial: The relationship between sarcopenia and metabolic diseases: Its formation mechanism and intervention means
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Qingfeng Cheng, Chaodong Wu, Lixin Guo, and Jinbo Hu
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sarcopenia ,intervention ,aging ,mechanism ,metabolic diseases ,Diseases of the endocrine glands. Clinical endocrinology ,RC648-665 - Published
- 2022
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42. Medications and medical costs for diabetes patients with or without chronic respiratory disease in Beijing, China: A retrospective study
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Jingtao Qiao, Zheng Tan, Xiaomao Xu, Yan Zhou, Weihao Wang, Jingyi Luo, Jingwen Fan, Qi Pan, and Lixin Guo
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chronic respiratory disease (CRD) ,diabetes mellitus ,hypoglycemic therapy ,medical cost ,medications ,Diseases of the endocrine glands. Clinical endocrinology ,RC648-665 - Abstract
AimsThe cost of drug regimens prescribed to Chinese patients has not been evaluated. This study aims to evaluate the medical costs and hypoglycemic agents for diabetes mellitus patients with or without chronic respiratory disease in Beijing, and to investigate the changes in the costs and number of antidiabetic medications used for diabetes patients with chronic respiratory disease from 2016 to 2018.MethodsThis observational, retrospective study included diabetes patients with outpatient medication records from Beijing Medical Insurance between 2016 and 2018. The medications, including hypoglycemic and nonhypoglycemic drugs, insulin dosage, comorbidities, diabetes-related complications, treatment strategies, and annual medical costs, were recorded.ResultsThis study included 2,853,036 diabetes patients from 2016 to 2018. About 18.95%–20.53% of patients with chronic respiratory disease were predominantly distributed among those aged 45–84 years (88.7%–89.1%). Diabetes patients with chronic respiratory disease used more medications (4.48 ± 2.41 vs. 3.76 ± 2.33) and had higher total annual drug costs (¥12,286 ± 10,385 vs. ¥9700 ± 9202) to treat more comorbidities (2.52 ± 1.53 vs. 2.05 ± 1.85) than those without chronic respiratory disease (p
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- 2022
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43. Effects of liraglutide or lifestyle interventions combined with other antidiabetic drugs on abdominal fat distribution in people with obesity and type 2 diabetes mellitus evaluated by the energy spectrum ct: A prospective randomized controlled study
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Dongni Yu, Mingzhu Zou, Qi Pan, Yan Song, Miao Li, Xianbo Zhang, Yan Zhou, Xiaoxia Wang, and Lixin Guo
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liraglutide ,obesity type 2 diabetes mellitus ,abdominal fat distribution ,type 2 diabetes ,diabetes ,Diseases of the endocrine glands. Clinical endocrinology ,RC648-665 - Abstract
ObjectiveTo study the effects of liraglutide or lifestyle interventions combined with other antidiabetic drugs on glucose metabolism and abdominal fat distribution in patients with obesity and type 2 diabetes mellitus (T2DM).MethodsFrom April 30, 2020, to April 30, 2022, a prospective randomized controlled study was carried out at the Endocrinology Department of Beijing Hospital, the National Center of Gerontology. According to the in- and exclusion criteria and by the random table method, revisited T2DM patients were selected as the research subjects and were allocated into a Study group (taking liraglutide) and a Control group (underwent lifestyle interventions). All patients received continuous 12-weeks interventions to the endpoint, and the changes of value [Δ=(endpoint)-(baseline)] of physical measurements, blood tests, the energy spectrum CT examination results, and body composition analysis results were analyzed and compared.ResultsA total of 85 people completed this study, and among them, 47 were in the Study group and 38 were in the Control group. Compared with the Control group, the changes of hemoglobin A1c (HbA1c) level (-0.78 ± 1.03% vs. -1.57 ± 2.00%, P=0.025), visceral fat area (0.91 ± 16.59 cm2 vs. -7.1 ± 10.17 cm2, P=0.011), and subcutaneous fat area of abdomen [0 (-18.75, 15.5) cm2 vs. -16.5 (-41.75, -2.25) cm2, P=0.014] were all greater in the Study group. The adverse events caused by liraglutide were mainly concentrated in the gastrointestinal system and all of them were minor adverse events.ConclusionLiraglutide can be the drug of choice for weight management and reduction of abdominal fat distribution in patients with obesity and T2DM.
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- 2022
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44. Screening and Identification of Hub Genes in the Development of Early Diabetic Kidney Disease Based on Weighted Gene Co-Expression Network Analysis
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Ran Wei, Jingtao Qiao, Di Cui, Qi Pan, and Lixin Guo
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bioinformatics ,WGCNA ,GSEA analysis ,early diabetic kidney disease ,hub gene ,Diseases of the endocrine glands. Clinical endocrinology ,RC648-665 - Abstract
ObjectiveThe study aimed to screen key genes in early diabetic kidney disease (DKD) and predict their biological functions and signaling pathways using bioinformatics analysis of gene chips interrelated to early DKD in the Gene Expression Omnibus database.MethodsGene chip data for early DKD was obtained from the Gene Expression Omnibus expression profile database. We analyzed differentially expressed genes (DEGs) between patients with early DKD and healthy controls using the R language. For the screened DEGs, we predicted the biological functions and relevant signaling pathways by enrichment analysis of Gene Ontology (GO) biological functions and Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathways. Using the STRING database and Cytoscape software, we constructed a protein interaction network to screen hub pathogenic genes. Finally, we performed immunohistochemistry on kidney specimens from the Beijing Hospital to verify the above findings.ResultsA total of 267 differential genes were obtained using GSE142025, namely, 176 upregulated and 91 downregulated genes. GO functional annotation enrichment analysis indicated that the DEGs were mainly involved in immune inflammatory response and cytokine effects. KEGG pathway analysis indicated that C-C receptor interactions and the IL-17 signaling pathway are essential for early DKD. We identified FOS, EGR1, ATF3, and JUN as hub sites of protein interactions using a protein–protein interaction network and module analysis. We performed immunohistochemistry (IHC) on five samples of early DKD and three normal samples from the Beijing Hospital to label the proteins. This demonstrated that FOS, EGR1, ATF3, and JUN in the early DKD group were significantly downregulated.ConclusionThe four hub genes FOS, EGR1, ATF3, and JUN were strongly associated with the infiltration of monocytes, M2 macrophages, and T regulatory cells in early DKD samples. We revealed that the expression of immune response or inflammatory genes was suppressed in early DKD. Meanwhile, the FOS group of low-expression genes showed that the activated biological functions included mRNA methylation, insulin receptor binding, and protein kinase A binding. These genes and pathways may serve as potential targets for treating early DKD.
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- 2022
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45. Early neurovascular changes in the retina in preclinical diabetic retinopathy and its relation with blood glucose
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Hui Li, Xiaobing Yu, Bodi Zheng, Shan Ding, Zhongqing Mu, and Lixin Guo
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Vessel density ,Acircularity index ,Retinal nerve fiber layer thickness ,Retinopathy ,Type 2 diabetes ,Ophthalmology ,RE1-994 - Abstract
Abstract Background To investigate the changes in retinal nerve fiber layer thickness and macular blood flow density during the preclinical stage of diabetic retinopathy and their relationship with blood glucose. Methods In this cross-sectional study, 97 diabetic patients (total of 188 eyes; 144 eyes in no diabetic retinopathy group, 44 eyes in mild diabetic non-proliferative retinopathy group) and 35 healthy people (70 eyes) were enrolled, All the subjects were divided into different groups based on their HbA1c levels, and they underwent optical coherence tomography angiography. We compared the optical coherence tomography angiography parameters and retinal nerve fiber layer thickness among the different glucose groups. Results The parafoveal vessel density and the temporal retinal nerve fiber layer thickness were lower (p
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- 2021
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46. Composite cardiovascular risk and BMI affected comparative profiles of BIAsp 30 + metformin vs BIAsp 30 monotherapy: a MERIT post-hoc analysis
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Lixin Guo, Baocheng Chang, Li Chen, Liyong Yang, Yu Liu, Bo Feng, and Qinghua He
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Medicine ,Science - Abstract
Abstract We assessed whether comparative efficacy and safety of biphasic insulin aspart 30 (BIAsp 30) plus metformin versus BIAsp 30 monotherapy differed for patients with type 2 diabetes mellitus (T2DM) inadequately controlled with oral antidiabetic drugs with different cardiovascular risk scores and different body mass indexes (BMI) by performing a post hoc analysis of the randomized controlled MERIT study. In the MERIT study, eligible patients were randomized 1:1 to receive BIAsp 30 plus metformin or BIAsp 30 for 16 weeks. Patients in the 2 treatment groups were classified into “low” and “high” risk subgroups based on their GloboRisk scores and into “BMI ≤ 26 kg/m2”and “BMI > 26 kg/m2” subgroups. Primary efficacy endpoint was between-treatments comparison of HbA1c changes from baseline for these 2 sets of subgroups. Between-treatments comparisons of secondary efficacy and safety endpoints were also performed. We found that BIAsp 30 plus metformin led to significantly higher percentage of high-risk patients achieving HbA1c target
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- 2021
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47. Time-Domain Scattering Characteristics and Jamming Effectiveness in Corner Reflectors
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Ying Luo, Lixin Guo, Yanchun Zuo, and Wei Liu
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Time-domain bouncing ray method ,jamming effectiveness evaluation ,passive jamming ,high-resolution range profile ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
The outboard corner reflectors are widely used as a countermeasure to radar tracking and detection. Therefore, it is essential to determine the composite time-domain scattering characteristics of the corner reflector and ship against the sea background and the jamming effectiveness of the corner reflector array. In this paper, the composite electromagnetic scattering characteristics of ship target, corner reflector, and the sea surface are studied based on the time-domain bouncing ray method (TDSBR). The radar echo and broadband radar cross section (RCS) results for the time domain pulse incident are also obtained and the high-resolution range profile (HRRP) is calculated. We then devise an evaluation system based on centroid jamming intensity and range profile similarity to determine the jamming characteristics of passive jamming. We further propose an array composing of three sizes of corner reflectors. Finally, the centroid jamming effectiveness is analyzed by comparing the RCS of the corner reflector array and the ship, and the deception jamming effectiveness is measured by calculating the range profile similarity based on the cosine similarity method and the range profile peak envelope overlap. Simulation results show that the reflector array can achieve a good performance both for centroid and range profile deception. The simulation results given and the evaluation method proposed in this paper provides significant practical insights into the design and analysis of the passive jamming systems.
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- 2021
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48. Jamming Efficiency Analysis Based on the Range Profile of Target With Chaff
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Yanchun Zuo, Lixin Guo, Wei Liu, and Jianyang Ding
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Range profile ,target recognition ,chaff cloud ,jamming performance analysis ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
Chaff cloud is widely used in target covering. In this paper, a jamming performance estimation strategy is presented for the elliptical and cubic chaff clouds. The range profiles of the composite models of the plane with the chaff cloud are experimentally accessed in an anechoic chamber using a stepped-frequency waveform measurement system. Then, dimensions, characteristic length, and distributing entropy of the equivalent scattering centers of the plane and the jammer are extracted from the measured range profiles, respectively. Based on these features, support vector machines, naïve Bayesian classification, and decision tree classification methods are employed to determine the recognition rate of the target under the chaff jamming, and then determine the jamming efficiency of the two kinds of chaff clouds. Results show that two types of chaff clouds are able to reduce the target recognition rate. Besides, when the radar uses the Euclidean distance and decision tree classification methods to complete the recognition task, a good jamming efficiency can be achieved by releasing the elliptical or the cubic chaff cloud. Meanwhile, a low level of jamming performance outcomes using the support vector machines classification method. It is also found that the chaff cloud released from the side of the plane achieves a better jamming performance compared with the other releasing locations. Finally, the influence of environmental noise on the recognition rate of the plane is studied. Estimating results show that the recognition rates decrease with the increasing of the power level of the noise. When the transmitting power level of the noise reaches 1.2 times the reflected power level of the target, it is quite hard to estimate the jamming performance of two kinds of chaff clouds.
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- 2021
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49. Performance Analysis for Cooperative Communication System in Optical IoUT Network With HDAF Strategy
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Shuang Li, Ping Wang, Weina Pang, Wei Wang, and Lixin Guo
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Internet of Underwater Things ,hybrid decode-amplify-forward ,underwater wireless optical communication ,beam spread function ,Applied optics. Photonics ,TA1501-1820 ,Optics. Light ,QC350-467 - Abstract
In this work, a cooperative optical Internet of Underwater Things (IoUT) system with hybrid decode-amplify-forward (HDAF) strategy is first proposed and investigated over the aggregated underwater wireless optical communication (UWOC) channel. The impacts of absorption, scattering and the misalignment caused by spatial spreading in the sea, which are modeled by the beam spread function (BSF), as well as the oceanic turbulence on the underwater optical links are all included to describe the practical channel characteristics. With the help of Gauss-Hermite and Gauss-Legendre quadrature numerical methods, the closed-form expressions of the average bit error ratio (ABER) and outage probability for this cooperative optical HDAF-IoUT system are derived and verified by the Monte Carlo (MC) simulations. Furthermore, numerical analyses are offered to explore the effects of water type, turbulence strength, relay location and power allocation scheme on this HDAF-IoUT system. The performance of this optical system over the mixture Exponential Generalized Gamma (EGG) channel is also given for comparison. The obtained results indicate that the optical HDAF-IoUT system is superior to the IoUT system with fixed amplify-and-forward (FAF) strategy, and has a better performance when the relay is close to the middle position for a fixed power allocation scheme. This work is beneficial for the cooperative system design in IoUT network.
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- 2021
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50. Spiral Spectrum of a Laguerre-Gaussian Beam Propagating in Anisotropic Turbulent Plasma
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Yankun Wang, Lu Bai, Danmeng Zhang, Jinyu Xie, Ya Guo, and Lixin Guo
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Orbital angular momentum ,spiral spectrum ,anisotropic turbulence ,Applied optics. Photonics ,TA1501-1820 ,Optics. Light ,QC350-467 - Abstract
The explicit expression of orbital angular momentum (OAM) spiral spectrum of Laguerre-Gaussian (LG) beam propagating in anisotropic plasma turbulence is derived based on Rytov theory. The relationship between the detection probability of OAM and the crosstalk with the anisotropy parameters, topological charge, radial index, wavelength, beam width, receiving aperture, inner and outer scales are discussed in detail. In order to quantify the effect of plasma turbulence, we compared it with atmospheric turbulence based on restriction function. To optimize OAM detection probability, we also compared the effects of circular aperture method (CAM) with focusing mirror method (FMM) on the propagation characteristics of the spiral spectrum. The results show that even in the strong turbulence region of atmospheric turbulence, the radial dimension of LG beam in plasma turbulence is nearly twice that of atmospheric turbulence and the modes crosstalk has almost reached its upper bound. Besides, by comparing the two optimization methods, we found the ability to reduce crosstalk is related to the choice of beam width and receiving aperture. Therefore, we give a method to optimally select between the CAM and the FMM. We found the corresponding relationship and gave an analytical formula. The FMM has a greater ability to reduce crosstalk than the CAM when the beam width ≥4 cm and the aperture ≥3 cm. We quantified the effect of plasma turbulence and provide a guideline for the selection of beam width and receiving aperture under these two optimization methods. The research results may be helpful in the field of optical communication.
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- 2021
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