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Hupo Bian,1 Shaoqi Zhu,2 Yonghua Zhang,3 Qiang Fei,4 Xiuhua Peng,1 Zanhui Jin,1 Tianxiang Zhou,5 Hongxing Zhao1,6 1Department of Radiology, The First Affiliated Hospital of Huzhou Normal University, Huzhou, Zhejiang, People’s Republic of China; 2Department of Endocrinology, The First Affiliated Hospital of Huzhou Normal University, Huzhou, Zhejiang, People’s Republic of China; 3Department of Radiology, The Wuxing District People’s Hospital, Huzhou, Zhejiang, People’s Republic of China; 4Department of Radiology, The Linghu People’s Hospital, Huzhou, Zhejiang, People’s Republic of China; 5Department of Urinary Surgery, The First Affiliated Hospital of Huzhou Normal University, Huzhou, Zhejiang, People’s Republic of China; 6Huzhou Key Laboratory of Precise Diagnosis and Treatment of Urinary Tumors, Huzhou, Zhejiang, 313000, People’s Republic of ChinaCorrespondence: Hongxing Zhao, Department of Radiology, The First Affiliated Hospital of Huzhou Normal University, No. 158, Plaza Back Road, Wuxing District, Huzhou City, Zhejiang Province, People’s Republic of China, Email zhx2113408@126.comObjective: A bibliometric analysis was conducted using VOSviewer and CiteSpace to examine studies published between 2009 and 2023 on the utilization of artificial intelligence (AI) in chronic obstructive pulmonary disease (COPD).Methods: On March 24, 2024, a computer search was conducted on the Web of Science (WOS) core collection dataset published between January 1, 2009, and December 30, 2023, to identify literature related to the application of artificial intelligence in chronic obstructive pulmonary disease (COPD). VOSviewer was utilized for visual analysis of countries, institutions, authors, co-cited authors, and keywords. CiteSpace was employed to analyze the intermediary centrality of institutions, references, keyword outbreaks, and co-cited literature. Relevant descriptive analysis tables were created using Excel2021 software.Results: This study included a total of 646 papers from WOS. The number of papers remained small and stable from 2009 to 2017 but started increasing significantly annually since 2018. The United States had the highest number of publications among countries/regions while Silverman Edwin K and Harvard Medical School were the most prolific authors and institutions respectively. Lynch DA, Kirby M. and Vestbo J. were among the top three most cited authors overall. Scientific Reports had the largest number of publications while Radiology ranked as one of the top ten influential journals. The Genetic Epidemiology of COPD (COPDGene) Study Design was frequently cited. Through keyword clustering analysis, all keywords were categorized into four groups: epidemiological study of COPD; AI-assisted imaging diagnosis; AI-assisted diagnosis; and AI-assisted treatment and prognosis prediction in the COPD research field. Currently, hot research topics include explainable artificial intelligence framework, chest CT imaging, and lung radiomics.Conclusion: At present, AI is predominantly employed in genetic biology, early diagnosis, risk staging, efficacy evaluation, and prediction modeling of COPD. This study’s results offer novel insights and directions for future research endeavors related to COPD.Keywords: chronic obstructive pulmonary disease, artificial intelligence, visual analysis, bibliometric analysis

Yiming Zhang,1,2,* Yiming Dou,1,2,* Yang Liu,1,2 Mingyuan Di,1,2 Hanming Bian,1,2 Xun Sun,1,2 Qiang Yang1,2 1Department of Spine Surgery, Tianjin Hospital, Tianjin University, Tianjin, People’s Republic of China; 2Clinical School of Orthopedics, Tianjin Medical University, Tianjin, People’s Republic of China*These authors contributed equally to this workCorrespondence: Xun Sun; Qiang Yang, Department of Spine Surgery, Tianjin Hospital, 406 Jiefang SouthRoad, Hexi District, Tianjin, 300211, People’s Republic of China, Email sunxun_tju@yeah.net; yangqiang1980@126.comAbstract: Extracellular vesicles (EVs) are nanoscale bilayer phospholipid membrane vesicles released by cells. Contained large molecules such as nucleic acid, protein, and lipid, EVs are an integral part of cell communication. The contents of EVs vary based on the cell source and play an important role in both pathological and physiological conditions. EVs can be used as drugs or targets in disease treatment, and changes in the contents of EVs can indicate the progression of diseases. In recent years, with the continuous exploration of the structure, characteristics, and functions of EVs, the potential of engineered EVs for drug delivery and therapy being constantly explored. This review provides a brief overview of the structure, characteristics and functions of EVs, summarizes the advanced application of EVs and outlook on the prospect of it. It is our hope that this review will increase understanding of the current development of medical applications of EVs and help us overcome future challenges.Keywords: extracellular vesicle, nanotherapeutic, disease diagnosis, engineered exosome, advances applications

Kai Li,1,2,* Peipei Duan,1,2,* Haifa He,3,* Ruijuan Du,1,2 Qian Wang,1,2 Pengju Gong,4 Hua Bian1 1Zhang Zhongjing College of Chinese Medicine, Nanyang Institute of Technology, Nanyang, Henan, People’s Republic of China; 2Henan Key Laboratory of Zhang Zhongjing Formulae and Herbs for Immunoregulation, Nanyang Institute of Technology, Nanyang, Henan, People’s Republic of China; 3Department of Pathology, Nanyang Central Hospital, Nanyang, Henan, People’s Republic of China; 4The University of Texas MD Anderson Cancer Center UThealth Graduate School of Biomedical Sciences, Houston, TX, USA*These authors contributed equally to this workCorrespondence: Hua Bian; Kai Li, Zhang Zhongjing College of Chinese Medicine, Nanyang Institute of Technology, No. 80 Changjiang Road, Wancheng District, Nanyang, Henan, People’s Republic of China, Email biancrown@163.com; likai718@whu.edu.cnIntroduction: Esophageal adenocarcinoma (EAC) is one of the histologic types of esophageal cancer with a poor prognosis. The majority of EAC originate from Barrett’s esophagus (BE). There are few studies focusing on the dynamic progression of BE to EAC.Methods: R software was used to analyze differentially expressed genes (DEGs) based on RNA-seq data of 94 normal esophageal squamous epithelial (NE) tissues, 113 BE tissues and 147 EAC tissues. The overlapping genes of DEGs between BE and EAC were analyzed by Venn diagram tool. The hub genes were selected by Cytoscape software based on the protein-protein interaction network of the overlapping genes using STRING database. The functional analysis of hub genes was performed by R software and the protein expression was identified by immunohistochemistry.Results: In the present study, we found a large degree of genetic similarity between BE and EAC, and further identified seven hub genes (including COL1A1, TGFBI, MMP1, COL4A1, NID2, MMP12, CXCL1) which were all progressively upregulated in the progression of NE-BE-EAC. We have preliminarily uncovered the probable molecular mechanisms of these hub genes in disease development and constructed the ceRNA regulatory network of hub genes. More importantly, we explored the possibility of hub genes as biomarkers in the disease progression of NE-BE-EAC. For example, TGFBI can be used as biomarkers to predict the prognosis of EAC patients. COL1A1, NID2 and COL4A1 can be used as biomarkers to predict the response to immune checkpoint blockade (ICB) therapy. We also constructed a disease progression risk model for NE-BE-EAC based on CXCL1, MMP1 and TGFBI. Finally, the results of drug sensitivity analysis based on hub genes showed that drugs such as PI3K inhibitor TGX221, bleomycin, PKC inhibitor Midostaurin, Bcr-Abl inhibitor Dasatinib, HSP90 inhibitor 17-AAG, and Docetaxel may be potential candidates to inhibit the progression of BE to EAC.Conclusion: This study is based on a large number of clinical samples with high credibility, which is useful for revealing the probable carcinogenic mechanism of BE to EAC and developing new clinical treatment strategies.Keywords: Barrett’s esophagus, esophageal adenocarcinoma, hub genes, carcinogenic mechanism, biomarker

Haiyan Bian,1 Lisheng Wang,2 Chengwen Gao,3 Zhihe Liu,1 Yang Sun,2 Minghui Hu,4 Yujing Xiao,5 Fengyun Hao,5 Yushuo Ma,1 Xia Zhao1 1Department of Hematology, the Affiliated Hospital of Qingdao University, Qingdao, People’s Republic of China; 2Laboratory of Molecular Diagnosis and Regenerative Medicine, the Affiliated Hospital of Qingdao University, Qingdao, People’s Republic of China; 3Laboratory of Medical Biology, the Affiliated Hospital of Qingdao University, Qingdao, People’s Republic of China; 4Clinical Laboratory, the Affiliated Hospital of Qingdao University, Qingdao, People’s Republic of China; 5Department of Pathology, the Affiliated Hospital of Qingdao University, Qingdao, People’s Republic of ChinaCorrespondence: Xia Zhao, Department of Hematology, the Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Shinan District, Qingdao, 266000, People’s Republic of China, Email zhaoxia@qdu.edu.cnPurpose: Primary central nervous system lymphoma (PCNSL) responds favorably to radiation, chemotherapy and targeted drug therapy. However survival is usually worse, the treatment-related drug resistance and recurrence are still clinical problems to be solved urgently. Studies have shown that cytokines are expressed in varying degrees in patients with lymphoma, which is significantly related to the progression, poor prognosis and drug resistance of lymphoma. We explore the expression and clinical significance of Th1/Th2/Th17 cytokines and lymphocyte subsets in patients with PCNSL to provide a more sufficient theoretical basis for its diagnosis and treatment.Patients and Methods: We measured and analysed the levels of Th1/Th2/Th17 cytokines and the distribution of lymphocyte subsets (including Treg cells, CD3+, CD4+, CD8+, CD19+, and CD4+/CD8+) in 39 patients with PCNSL and 96 patients with diffuse large B-cell lymphoma (DLBCL) without central nervous system involvement. The cytokines of 13 healthy people and the lymphocyte subsets of 27 healthy people were measured as the control group.Results: We found a significant difference in the level of Th1/Th2/Th17 cytokines and lymphocyte subsets between PCNSL and healthy controls, especially IL-2, after treatment, which was significantly higher than before treatment (p< 0.01). However, the level of CD19+ and CD4+/CD8+ decreased while CD8+ and CD3+ increased after treatment (regardless of whether the treatment was effective), and the difference was statistically significant. In addition, our analysis of different prognostic factors found that HD-MTX-based chemotherapy appears to have a longer progression-free survival and overall survival than osimertinib-based chemotherapy.Conclusion: There are significant differences in Th1/Th2/Th17 cytokines and lymphocyte subsets among PCNSL, DLBCL, and healthy controls, and their detection is helpful for the diagnosis, treatment, and prognosis of PCNSL. HD-MTX-based chemotherapy may still be the first choice for PCNSL.Keywords: PCNSL, Th1/Th2/Th17 cytokines, lymphocyte subsets, HD-MTX, osimertinib

Zhao-Yin Ma,1,&ast; Yong-Ya Wu,2,&ast; Hong-Yin-Long Cui,3 Guang-Yan Yao,3 Hong Bian3,4 1Department of Diagnostic, Medical Integration and Practice Center, Shandong University, Jinan, Shandong, People’s Republic of China; 2Department of Emergency Critical Care Medicine, The Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, People’s Republic of China; 3Department of Neurology, Central Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People’s Republic of China; 4Department of Neurology, Jinan Central Hospital, Shandong University, Jinan, Shandong, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Hong Bian, Department of Neurology, Central Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People’s Republic of China, Tel +86-15318816109, Fax +86-053188382085, Email jnbianh@163.comObjective: Type 2 diabetes mellitus (T2DM) and ischemic stroke, which are common diseases among older people, are closely related to cognitive impairment. This study aims to investigate the influencing factors of post-stroke cognitive impairment (PSCI) in patients with T2DM.Methods: We enrolled 161 patients with T2DM who experienced acute ischemic stroke and were hospitalized in the Department of Neurology, Jinan Central Hospital, Shandong, China. Cognitive function was evaluated with the Montreal Cognitive Assessment scale. According to the results, patients were divided into three groups—the cognitively normal group, mild cognitive impairment group, and severe cognitive impairment group. We analyzed general demographic data, laboratory information, imaging data, the results of neuropsychological evaluation, and clinical features as well as influencing factors of PSCI in these patients and established a prediction model.Results: The three groups of patients were significantly different in terms of age, education level, course of diabetes mellitus (DM), recurrent cerebral infarction (RCI), and other factors. RCI, course of DM, and glycated hemoglobin (HbA1c) were independent risk factors of PSCI in patients with T2DM, with odds ratio (95% confidence interval): 7.17 (2.09, 30.37), 5.39 (2.40, 14.59), and 3.89 (1.66, 10.04), respectively, whereas female, senior high school, serum albumin were protective factors: 0.28 (0.07, 0.95), 0.05 (0.01, 0.21), 0.20 (0.08, 0.42), respectively. Furthermore, we constructed a prediction model using sex, age, education level, RCI, DM course, HbA1c and serum albumin and obtained a receiver operating characteristic (ROC) curve. The area under the ROC curve is 0.966, suggesting the significant association of these influencing factors with PSCI in patients with T2DM.Conclusion: In this study, the occurrence of PSCI in patients with T2DM was related to RCI, course of DM, and HbA1c, among other factors. Attention to influencing factors is needed in these patients for early diagnosis and timely intervention of cognitive impairment.Keywords: blood glucose, cognitive impairment, ischemic stroke, risk factor

Sha Chen,1 Hao Bian,2 Jingyu Duan1 1Department 2 of Ultrasound, Cangzhou Central Hospital, Cangzhou, 061000, Hebei, People’s Republic of China; 2Magnetic Resonance Imaging Department, Cangzhou Central Hospital, Cangzhou, 061000, Hebei, People’s Republic of ChinaCorrespondence: Sha Chen, Department 2 of Ultrasound, Cangzhou Central Hospital, No. 16, Xinhua West Road, Yunhe District, Cangzhou, 061000, Hebei, People’s Republic of China, Tel +86-18232858958, Email haoshalin2013@163.comBackground: Paclitaxel (PTX) is an important oncologic chemotherapeutic agent against breast cancer, but breast cancer patients develop significant resistance to PTX during chemotherapy. Alterations in tubulin and associated proteins have been implicated in resistance to PTX. High-intensity focused ultrasound (HIFU) induces deep tumor penetration of anti-tumor agents in solid tumors.Methods: We investigated the influence of HIFU on the anti-tumor activities of PTX in breast cancer. Both in vivo and in vitro experiments were performed in this research: mice were treated with 2 mg/Kg PTX through tail vein injection, while breast cancer cells were treated with 400 nM PTX. Cell viability was analyzed through Cell Counting Kit-8. Cell apoptosis was evaluated through Annexin-V/PI Apoptosis Analysis Kit. The activities of catalase (CAT) and superoxide dismutase (SOD) and the concentration of malondialdehyde (MDA) were evaluated by relative commercial kits.Results: HIFU enhanced PTX-inhibited breast cancer cell viability and PTX-induced cell apoptosis. Simultaneous treatment of HIFU and PTX decreased the activities of CAT and SOD and increased the concentration of MDA. In mice bearing MDA-MB-231 tumors, the treatment of HIFU and PTX significantly decreased tumor size, increased body weight and elevated animal survival. HIFU enhanced the distribution of PTX in tumor tissues.Conclusion: The performance of HIFU promoted the distribution of PTX and enhanced its anti-tumor activities in breast cancer.Keywords: breast cancer, paclitaxel, high-intensity focused ultrasound, cancer therapy

Daye Chen, Hongliang Bian, Lanlan Zhang Department of Pediatrics, Yancheng Maternal and Child Health Hospital, Yancheng, People’s Republic of China Objective: The objective of this study was to investigate the efficacy and safety profile of levetiracetam as add-on therapy in patients with refractory epilepsy.Methods: Web of Science, MEDLINE (Ovid and PubMed), Cochrane Library, EMBASE, and Google Scholar were systematically searched to identify potential eligible randomized controlled trials by two reviewers independently. Pooled estimates of risk ratios (RRs) for 50%, 75%, and 100% reduction from baseline were calculated using the fixed-effect model or random-effect model. Quality of included studies was assessed with the Cochrane Collaboration’s Risk of Bias tool. Serious adverse events and withdrawals induced by interventions and the most common side effects were analyzed.Results: Seventeen trials with a total of 3,205 participants were included in this meta-analysis, including 14 trials for adulthood and three trials for children. Pooled estimates suggested that levetiracetam was an effective anti-epileptic drug at 1,000–3,000 mg/day (RR =2.00 for 1,000 mg/day, RR =2.68 for 2,000 mg/day, RR =2.18 for 3,000 mg/day) for adults and 60 mg/kg/day (RR =2.00) for children compared to placebo in terms of 50% reduction from baseline. Likewise, as for seizure freedom rate, levetiracetam had an advantage over placebo at 1,000–3,000 mg/day (RR =5.84 for 1,000 mg/day, RR =4.55 for 2,000 mg/day, RR =4.57 for 3,000 mg/day, respectively) for adults and 60 mg/kg/day (RR =4.52) for children. Regarding safety profile, patients treated with levetiracetam had significantly higher occurrence than placebo for somnolence, asthenia, dizziness, infection, nasopharyngitis, anxiety, and irritability; however, most studies reported that these adverse events were mild and transient.Conclusion: Levetiracetam is an effective anti-epileptic drug for both adults and children with generalized or partial-onset refractory seizures at 1,000–3,000 or 60 mg/kg/day, with a favorable adverse event profile. Keywords: levetiracetam, adjunctive, refractory epilepsy, placebo

Quantifying the carbonyl sulfide (OCS) land/ocean fluxes contributes to the understanding of both the sulfur and carbon cycles. The primary sources and sinks of OCS are very likely in a steady state because there is no significant observed trend or interannual variability in atmospheric OCS measurements. However, the magnitude and spatial distribution of the dominant ocean source are highly uncertain due to the lack of observations. In particular, estimates of the oceanic fluxes range from approximately 280 Gg S yr-1 to greater than 800 Gg S yr-1, with the larger flux needed to balance a similarly sized terrestrial sink that is inferred from NOAA continental sites. Here we estimate summer tropical oceanic fluxes of OCS in 2006 using a linear flux inversion algorithm and new OCS data acquired by the Aura Tropospheric Emissions Spectrometer (TES). Modeled OCS concentrations based on these updated fluxes are consistent with HIAPER Pole-to-Pole Observations during 4th airborne campaign and improve significantly over the a priori model concentrations. The TES tropical ocean estimate of 70±16GgS in June,when extrapolated over the whole year (about 840 ± 192 Gg S yr-1), supports the hypothesis proposed by Berry et al. (2013) that the ocean flux is in the higher range of approximately 800 Gg S yr-1.

This paper evaluates the current status of global modeling of the organic aerosol (OA) in the troposphere and analyzes the differences between models as well as between models and observations. Thirty-one global chemistry transport models (CTMs) and general circulation models (GCMs) have participated in this intercomparison, in the framework of AeroCom phase II. The simulation of OA varies greatly between models in terms of the magnitude of primary emissions, secondary OA (SOA) formation, the number of OA species used (2 to 62), the complexity of OA parameterizations (gas-particle partitioning, chemical aging, multiphase chemistry, aerosol microphysics), and the OA physical, chemical and optical properties. The diversity of the global OA simulation results has increased since earlier AeroCom experiments, mainly due to the increasing complexity of the SOA parameterization in models, and the implementation of new, highly uncertain, OA sources. Diversity of over one order of magnitude exists in the modeled vertical distribution of OA concentrations that deserves a dedicated future study. Furthermore, although the OA / OC ratio depends on OA sources and atmospheric processing, and is important for model evaluation against OA and OC observations, it is resolved only by a few global models. The median global primary OA (POA) source strength is 56 Tg a-1 (range 34-144 Tg a-1) and the median SOA source strength (natural and anthropogenic) is 19 Tg a-1 (range 13-121 Tg a-1). Among the models that take into account the semi-volatile SOA nature, the median source is calculated to be 51 Tg a-1 (range 16-121 Tg a-1), much larger than the median value of the models that calculate SOA in a more simplistic way (19 Tg a-1; range 13-20 Tg a-1, with one model at 37 Tg a-1). The median atmospheric burden of OA is 1.4 Tg (24 models in the range of 0.6-2.0 Tg and 4 between 2.0 and 3.8 Tg), with a median OA lifetime of 5.4 days (range 3.8-9.6 days). In models that reported both OA and sulfate burdens, the median value of the OA/sulfate burden ratio is calculated to be 0.77; 13 models calculate a ratio lower than 1, and 9 models higher than 1. For 26 models that reported OA deposition fluxes, the median wet removal is 70 Tg a-1 (range 28-209 Tg a-1), which is on average 85% of the total OA deposition. Fine aerosol organic carbon (OC) and OA observations from continuous monitoring networks and individual field campaigns have been used for model evaluation. At urban locations, the model-observation comparison indicates missing knowledge on anthropogenic OA sources, both strength and seasonality. The combined model-measurements analysis suggests the existence of increased OA levels during summer due to biogenic SOA formation over large areas of the USA that can be of the same order of magnitude as the POA, even at urban locations, and contribute to the measured urban seasonal pattern. Global models are able to simulate the high secondary character of OA observed in the atmosphere as a result of SOA formation and POA aging, although the amount of OA present in the atmosphere remains largely underestimated, with a mean normalized bias (MNB) equal to -0.62 (-0.51) based on the comparison against OC (OA) urban data of all models at the surface, -0.15 (+0.51) when compared with remote measurements, and -0.30 for marine locations with OC data. The mean temporal correlations across all stations are low when compared with OC (OA) measurements: 0.47 (0.52) for urban stations, 0.39 (0.37) for remote stations, and 0.25 for marine stations with OC data. The combination of high (negative) MNB and higher correlation at urban stations when compared with the low MNB and lower correlation at remote sites suggests that knowledge about the processes that govern aerosol processing, transport and removal, on top of their sources, is important at the remote stations. There is no clear change in model skill with increasing model complexity with regard to OC or OA mass concentration. However, the complexity is needed in models in order to distinguish between anthropogenic and natural OA as needed for climate mitigation, and to calculate the impact of OA on climate accurately.

We use aircraft observations obtained during the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission to examine the distributions and source attributions of O 3 and NO y in the Arctic and sub-Arctic region. Using a number of marker tracers, we distinguish various air masses from the background troposphere and examine their contributions to NO x, O 3, and O 3 production in the Arctic troposphere. The background Arctic troposphere has a mean O 3 of ∼60 ppbv and NO x of ∼25 pptv throughout spring and summer with CO decreasing from ∼145 ppbv in spring to ∼100 ppbv in summer. These observed mixing ratios are not notably different from the values measured during the 1988 ABLE-3A and the 2002 TOPSE field campaigns despite the significant changes in emissions and stratospheric ozone layer in the past two decades that influence Arctic tropospheric composition. Air masses associated with stratosphere-troposphere exchange are present throughout the mid and upper troposphere during spring and summer. These air masses, with mean O 3 concentrations of 140-160 ppbv, are significant direct sources of O 3 in the Arctic troposphere. In addition, air of stratospheric origin displays net O 3 formation in the Arctic due to its sustainable, high NO x (75 pptv in spring and 110 pptv in summer) and NO y (∼800 pptv in spring and ∼1100 pptv in summer). The air masses influenced by the stratosphere sampled during ARCTAS-B also show conversion of HNO 3 to PAN. This active production of PAN is the result of increased degradation of ethane in the stratosphere-troposphere mixed air mass to form CH 3CHO, followed by subsequent formation of PAN under high NO x conditions. These findings imply that an adequate representation of stratospheric NO y input, in addition to stratospheric O 3 influx, is essential to accurately simulate tropospheric Arctic O 3, NO x and PAN in chemistry transport models. Plumes influenced by recent anthropogenic and biomass burning emissions observed during ARCTAS show highly elevated levels of hydrocarbons and NO y (mostly in the form of NO x and PAN), but do not contain O 3 higher than that in the Arctic tropospheric background except some aged biomass burning plumes sampled during spring. Convection and/or lightning influences are negligible sources of O 3 in the Arctic troposphere but can have significant impacts in the upper troposphere in the continental sub-Arctic during summer. © 2011 Author(s).

We describe a model for predicting the size-resolved distribution of atmospheric dust for climate and chemistry-related studies. The dust distribution from 1990 to 1999 is simulated with our mineral aerosol entrainment and deposition module embedded in a chemical transport model. Mobilization processes include entrainment thresholds for saltation, moisture inhibition, drag partitioning, and saltation feedback. For mobilization we assume that soil texture is globally uniform and is replete with saltators. Soil erodibility is prescribed by a new physically based geomorphic index that is proportional to the runoff area upstream of each source region. Dry deposition processes include sedimentation and turbulent mix-out. Nucleation scavenging and size-resolved washout in both stratiform and convective cloud types are represented. Simulations of the 1990s broadly agree with station observations and satellite-inferred dust distributions. Without invoking anthropogenic mechanisms the model captures the seasonal migration of the transatlantic African dust plume, and it captures the spring maximum in Asian dust outflow and concentration over the Pacific. We estimate the 1990s global annual mean and variability ofD < 10 μm dust to be the following: emissions, 1490 ± 160 Tg yr−1; burden, 17 ± 2 Tg; and optical depth at 0.63 μm, 0.030 ± 0.004. This emission, burden, and optical depth are significantly lower than some recent estimates. The model underestimates transport and deposition of East Asian and Australian dust to some regions of the Pacific Ocean. An underestimate of long-range transport of particles larger than 3 μm contributes to this bias. Our experiments support the hypothesis that dust emission “hot spots” exist in regions where alluvial sediments have accumulated and may be disturbed.

Abstract The East Asian summer monsoon precipitation has exhibited a well-known “southern China flood and northern China drought” pattern in recent decades. The increase in aerosols and warming oceans are recognized as two important forcings that control of the precipitation trends over East Asian land. However, in this study, by using large ensemble simulations from the CMIP6 Polar Amplification Model Intercomparison Project (PAMIP), the influence of Arctic amplification, serving as the prominent feature of global warming, is very important in modulating the East Asian summer precipitation pattern, which is comparable to the influence of sea surface temperature (SST). Additionally, the observed “southern China flood and northern China drought” pattern only exists in July and August, whereas a triple pattern with the precipitation positive anomaly center over Middle China occurs in June. These patterns are closely connected with the regional differences in Arctic sea ice loss from June to July, affected through both the Rossby waves propagating in a weaker westerly jet and the decrease in the large-scale meridional thermal contrast in a warming climate.

In this study, based on the rainfall measurements from weather stations over China and atmospheric reanalysis products from the fifth-generation European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis (ERA5) during the period of 1979-2020, the dynamic mechanisms and differences of persistent rainstorm (PRS) events and extreme intense rainfall (EIR) events over the Yangtze-Huaihe Meiyu domain (YMD) are revealed from the perspective of potential vorticity (PV)-forced vertical motion. According to the improved definitions of PRS and EIR events, 24 PRS events and 24 EIR cases are identified over the YMD during the Meiyu period from 1979 to 2020. Composite analyses for the two types of events demonstrate that the most intense rainband of PRS events is mainly located in the Yangtze River and over the southern regions of it, while for the EIR, the most intense rainband is located in the Yangtze River and over the northern regions of it. The PRS events are found to be closely related to tropical atmospheric intraseasonal oscillation, during which the upper-tropospheric South Asian high extends more eastward, while the northwestern Pacific subtropical anticyclone in the lower and middle troposphere shifts more westward. Thus, the dry and cold air with high-PV around the upper-tropospheric westerly jet located more southward latitudes tends to intrude equatorward and downward, converging with the warm and moist air from the southwest in the lower and middle troposphere to form Meiyu front. However, the EIR events are more dependent to a greater extent on the upper-tropospheric divergence on the southern side of the westerly jet located more northward latitudes and PV-forced downward-intruding cold air. The quantitative diagnoses of PV budget for EIR events show that before and during the peak of intense rainfall, the net negative PV tendency in the upper troposphere is mainly dominated by the negative vertical PV advection, while the positive PV tendency in the middle and lower troposphere is mainly caused by the PV generation due to the vertically non-uniform diabatic heating and vertical PV advection. The vertical velocity decomposition of a typical EIR event further demonstrates that the component of ascending velocity forced by the vertical increase of horizontal PV advection plays an important role in triggering the EIR event.

Frequency is one of the most significant indicators of power system, which needs accurate estimation to provide a reliable basis for monitoring, control, and protection. Owning to the efficiency, DFT is widely used in the frequency measurement of power systems. However, the inherent defects, that is, the spectral leakage and picket fence effect, decrease the accuracy of DFT. One of the variants, named the windowed phase difference method (WPD), addresses the problem using the phase variation of two windowed sequences in the frequency domain and achieves accurate frequency estimation. Suffering from the ignored negative component and contamination of noise, there are still undesired errors in WPD-based frequency estimation. To reduce the influence of the undesired errors, this paper first analyzes the systematic error of WPD introduced by spectrum leakage and proposes an improved WPD (IWPD) through systematic error compensation to achieve more accurate frequency estimations. Then, the windowing effect on IWPD-based frequency estimation of a noisy signal is studied by deducing the theoretical expression of frequency estimation variance. Finally, the proposed IWPD is validated by extensive computer simulations and practical experiments.

Abstract Using reanalysis data and simulations, this study revealed a pronounced negative interannual relationship between tropical southern Atlantic (TSA) sea surface temperature (SST) and East Asian surface air temperature (SAT) during boreal spring (March–May). Results confirm that the March–May TSA–SST anomaly can be considered an independent tropical driver unrelated to El Niño–Southern Oscillation. A possible mechanism linking TSA–SST and East Asian spring SAT involves an atmospheric wave train, energy conversion, and potential vorticity (PV)–θ dynamics. The anomalous TSA–SST induces an anomalous Walker circulation, which initiates a wave train that extracts energy from a westerly jet and propagates toward East Asia. Subject to PV–θ dynamics, the East Asian PV anomaly embedded within this wave train leads to bowed isentropes and resultant notable anomalous East Asian SAT. In particular, the bootstrapping results suggest that TSA–SST anomaly can cause an approximately sevenfold increase in the occurrence probability of extreme East Asian spring SAT.