Search

Zimin Wu,1,* Sisi Mo,2,* Zuyuan Huang,1 Baoshi Zheng1 1Department of Cardiovascular Surgery Ward, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region, 530021, People’s Republic of China; 2Department of Medical Research, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region, 530021, People’s Republic of China*These authors contributed equally to this workCorrespondence: Baoshi Zheng, Department of Cardiovascular Surgery Ward, the First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Qingxiu District, Nanning, Guangxi Zhuang Autonomous Region, 530021, People’s Republic of China, Tel +86 0771-5355280, Email baoshizhengyx@163.comBackground: Peripheral biomarkers are becoming an important method by which to monitor the progression of coronary artery disease (CAD). Not only are they minimally invasive and early detection, but they can also be used for classification and diagnosis of disease as well as prognostic assessment. Currently, this approach is still in the exploratory stage. The purpose of this research is to determine the diagnostic value and therapeutic potential of the endoplasmic reticulum stress (ERS) genes in CAD.Methods: The clinical information and RNA sequence data were obtained from the GEO database and subsequently subjected to a series of optimization and visualization processes using various analytical techniques, including WGCNA, LASSO, SVM-RFE feature selection, random forest (RF), and XGBoost, as well as R software and Cytoscape. Finally, immunofluorescence was used to validate the analysis.Results: We identify 6 key ERS differentially expressed genes (ERS-DEGs) (UFL1, HSPA1A, ERLIN1, LRRK2, ERN1, SERINC3) for constructing diagnostic models. They showed qualified diagnostic ability as biomarkers of CAD within training dataset (AUC = 0.803) and validation dataset (AUC = 0.776 and 0.797). Association analyses showed that peripheral immune cells, immune checkpoint genes and Human Leukocyte Antigen (HLA) genes had characteristic distributions in CAD and were closely related to specific ERS genes. Meanwhile, we found that HSPA1A may involve the MAPK signaling pathway in CAD.Conclusion: We constructed an efficient diagnostic model based on 6 key ERS-DEGs and explored their regulatory networks and effects on the CAD immune microenvironment. UFL1, HSPA1A, ERLIN1, LRRK2, ERN1, SERINC3 are expected to be biomarkers for CAD.Keywords: endoplasmic reticulum stress, coronary artery disease, HSPA1A, immune microenvironment

Jiale Xu,&ast; Musen Xu,&ast; Xin Gao, Jiahang Liu, Jingchao Sun, Ruiqi Ling, Xuchen Zhao, Xifeng Fu, Shaojian Mo, Yanzhang Tian Department of Biliary and Pancreatic Surgery, Third Hospital of Shanxi Medical University, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Taiyuan, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Yanzhang Tian, Third Hospital of Shanxi Medical University, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, No. 99, Longcheng Street, Xiaodian District, Taiyuan, Shanxi Province, People’s Republic of China, Phone/Fax +86-13903512030, Email tyz2030@163.comObjective: To analyze the influence of diabetes mellitus on the clinical outcomes of moderately severe acute pancreatitis (MSAP) and severe acute pancreatitis (SAP).Methods: This retrospective study included patients diagnosed with MSAP and SAP at Shanxi Bethune Hospital from January 1, 2017, to December 31, 2021. Clinical data were collected, including patient demographics, 24-hour laboratory indicators, and inflammation indices. Propensity score matching (PSM) was used to compare outcomes before and after matching. Patients were randomized into training and validation sets (7:3) to develop and validate a clinical prediction model for infected pancreatic necrosis (IPN).Results: Among 421 patients, 79 had diabetes at admission. Before PSM, diabetic patients had higher incidences of peripancreatic fluid (71% vs 47%, p< 0.001) and IPN (48% vs 10%, p< 0.001), higher surgical intervention rates (24% vs 12%, p=0.008), and significant differences in abdominocentesis (22% vs 11%, p=0.014). After PSM, 174 patients were matched, and the diabetes group still showed higher incidences of peripancreatic fluid (69% vs 47%, p=0.008), IPN (48% vs 11%, p< 0.001), and surgical intervention rates (27% vs 13%, p=0.037). Diabetes, modified CT severity index (MCTSI), serum calcium, and HDL-c were identified as independent risk factors for IPN. The prediction model demonstrated good predictive value.Conclusion: In MSAP and SAP patients, diabetes mellitus can exert an influence on their clinical outcome and is an independent risk factor for IPN. The alignment diagram and web calculator constructed on the basis of diabetes mellitus, modified CT severity index (MCTSI), serum calcium and high-density lipoprotein cholesterol (HDL-c) have good predictive value and clinical guidance for the occurrence of IPN in MSAP and SAP.Keywords: acute pancreatitis, diabetes, propensity score matching, predictive model

Xin Gao,1 Jiale Xu,2 Musen Xu,2 Pengzhe Han,2 Jingchao Sun,2 Ruifeng Liang,1 Shaojian Mo,2,&ast; Yanzhang Tian2,&ast; 1School of Public Health, Shanxi Medical University, Taiyuan, People’s Republic of China; 2Department of Biliary and Pancreatic Surgery, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Shanxi Bethune Hospital, Third Hospital of Shanxi Medical University, Taiyuan, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Shaojian Mo; Yanzhang Tian, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Third Hospital of Shanxi Medical University, Taiyuan, People’s Republic of China, Tel +8619834514208 ; +8613903512030, Email 1009184648@qq.com; tyz2030@163.comPurpose: Acute pancreatitis is a common gastrointestinal emergency. Approximately 20% of patients with acute pancreatitis develop organ failure, which is significantly associated with adverse outcomes. This study aimed to establish an early prediction model for persistent organ failure in acute pancreatitis patients using 24-hour admission indicators.Patients and Methods: Clinical data and 24-h laboratory indicators of patients diagnosed with acute pancreatitis from January 1, 2017 to January 1, 2022 in Shanxi Bethune Hospital were collected. Patients from 2017 to 2021 were used as the training cohort to establish the prediction model, and patients from 2021 to 2022 were used as the validation cohort. Univariate logistic regression and LASSO regression were used to establish prediction models. The performance of the model was evaluated using area under the curve (AUC), calibration curves, and decision curve analysis (DCA), and subsequently validated in the validation group.Results: A total of 1166 patients with acute pancreatitis were included, a total of 145 patients suffered from persistent organ failure from 2017 to 2021. Data were initially selected for 100 variables, and after inclusion and exclusion, 46 variables were used for further analysis. Two prediction models were established and nomogram was drawn respectively. After comparison, the prediction values of the two models were similar (The univariate model AUC was 0.867, 95% CI (0.834– 0.9). The LASSO model AUC was 0.864, 95% CI (0.828– 0.895)), and the model established by LASSO regression was more parsimonious. A web calculator was developed using the model established by LASSO.Conclusion: Predictive model including 6 risk indicators can be used to predict the risk of persistent organ failure in patients with acute pancreatitis.Keywords: prediction model, LASSO regression, acute pancreatitis, nomogram, organ failure

Weiya Zeng,1– 3 Yuan Fang,1– 3 Suifen Mo,1– 3 Caihong Shen,1– 3 Huiling Yang,1– 3 Guihua Luo,1– 3 Luhua Xiao,1– 3 Ruoting Zhan,1– 3 Ping Yan1– 3 1College of Traditional Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, People’s Republic of China; 2Key Laboratory of Chinese Medicinal Resources from Lingnan (Guangzhou University of Chinese Medicine), Ministry of Education, Guangzhou, People’s Republic of China; 3Joint Laboratory of Nation Engineering Research Center for the Pharmaceutics of Traditional Chinese Medicines, Guangzhou, People’s Republic of ChinaCorrespondence: Ruoting Zhan; Ping Yan, Guangzhou University of Chinese Medicine, No. 232, Outer Ring East Road, Guangzhou, Guangdong, People’s Republic of China, Tel/Fax +86 20-39358045, Email ruotingzhan@vip.163.com; yanping@gzucm.edu.cnPurpose: Rubia cordifolia L. (RC) is a classic herbal medicine for the treatment of rheumatoid arthritis (RA) and has been used since ancient times. The ethanol extract of Rubia cordifolia L. (RCE) showed obvious anti-RA effects in our previous study. However, further potential mechanisms require more exploration. We aimed to investigate the mechanism of RCE for the treatment of RA by integrating metabolomics and network pharmacology in this study.Methods: An adjuvant-induced arthritis (AIA) rat model was established, and we evaluated the therapeutic effects of RCE. Metabolomics of serum and urine was used to identify the differential metabolites. Network pharmacology was applied to determine the key metabolites and potential targets. Finally, the potential targets and compounds of RCE were verified by molecular docking.Results: The results indicated that RCE suppressed foot swelling and alleviated joint damage and also had anti-inflammatory properties by inhibiting the expressions of tumor necrosis factor (TNF)-α, Interleukin (IL)-1β, prostaglandin E2 (PGE2), and P65. Ten and seven differential metabolites were found in the serum and urine, respectively, of rats. Six key targets, ie, phospholipase A2 group IIA (PLA2G2A), phospholipase A2 group X (PLA2G10), cytidine deaminase (CDA), uridine-cytidine kinase 2 (UCK2), charcot-leyden crystal galectin (CLC), and 5′,3′-nucleotidase, mitochondrial (NT5M), were discovered by network pharmacology and metabolite analysis and were found to be related to glycerophospholipid metabolism and pyrimidine metabolism. Molecular docking confirmed that the favorable compounds showed affinities with the key targets, including alizarin, 6-hydroxyrubiadin, ruberythric acid, and munjistin.Conclusion: This study revealed the underlying mechanisms of RCE and provided evidence that will allow researchers to further investigate the functions and components of RCE against RA.Keywords: inflammtion, AIA rats, molecular docking, chronic disease

Mengqian Cai,1 Miaoling Cui,1 Ying Nong,2 Jinlian Qin,1 Sucai Mo1 1Department of Nursing, The First Hospital Affiliated of Guangxi Medical University, Nanning, People’s Republic of China; 2Respiratory Medicine, The First Hospital Affiliated of Guangxi Medical University, Nanning, People’s Republic of ChinaCorrespondence: Miaoling Cui, Tel +8613878134966, Email cuimiaoling@126.comPurpose: To explore the trajectory of patient-reported outcomes and the factors influencing them in patients with COPD.Patients and Methods: The study population, 236 patients with stable COPD who attended the outpatient clinic of the Department of Respiratory and Critical Care Medicine in a tertiary care hospital in Nanning City between October 2020 and November 2021, answered the modified patient-reported outcome scale for COPD (mCOPD-PRO). Patient-reported outcomes were investigated at the time of the patient’s outpatient visit (T1), 1 month after the visit (T2), 3 months after the visit (T3), and 6 months after the visit (T4). Latent class growth modeling was used to determine the number and shape of trajectories, and multinomial logistic regression analysis were used to explore influence factors of each class.Results: COPD patients’ reported outcome trajectories were classified into 3 categories: health low-level group (14.80%), health risk group (54.70%), and good health group (30.50%). Logistic regression analysis showed that gender, BMI, smoking history, number of comorbidities, whether it was their first visit, and lung function classification were influential factors in patients’ reported outcome trajectories (P< 0.05). Female, obese, had a history of smoking, number of comorbid diseases > 3, first diagnosis, and lung function class IV had a higher probability of entering the healthy low-level group.Conclusion: COPD patients have poor self-reported health levels during the first 6 months after the outpatient visit, and there is group heterogeneity in patient-reported outcome trajectories; medical staff should give patients specific nursing interventions based on their current development of COPD, self-reported changes, and other relevant influencing factors.Keywords: chronic obstructive pulmonary disease, patient-reported outcomes, trajectory, latent class growth model

Mengqian Cai,1 Miaoling Cui,1 Ying Nong,2 Jinlian Qin,1 Sucai Mo1 1Department of Nursing, the First Hospital Affiliated of Guangxi Medical University, Nanning, People’s Republic of China; 2Respiratory Medicine, the First Hospital Affiliated of Guangxi Medical University, Nanning, People’s Republic of ChinaCorrespondence: Miaoling Cui, Tel + 86 138 7813 4966, Email cuimiaoling@126.comPurpose: To explore the health priorities of patients with multimorbidity in COPD and the factors as to why their condition is prioritized.Methods: This qualitative study was conducted from February to April 2022 at a hospital in China. A specially selected sample of 18 patients completed a general information sheet and face-to-face interviews. The Colaizzi method was used to analyze the data.Results: Participants reported their experience which fell into three themes: disease burden, health perception and views of others. In addition, participants explained that health knowledge from short videos on mobile apps influenced them, which in turn influenced their ranking.Conclusion: Our findings suggested that health priorities of patients with multimorbidity in COPD manifest differently. Specifically, our findings suggested that patients’ health priorities are most influenced by disease burden, health perception, and the opinions of those around them. Nursing staff should fully understand each patients’own perspectives and provide them with personalized support.Keywords: chronic obstructive pulmonary disease, health priorities, multimorbidity, multiple chronic conditions, qualitative research

Jing Zhang,1,2 YanZhang Tian,1 ShaoJian Mo,1 XiFeng Fu1 1Department of Biliary and Pancreatic Surgery, Third Hospital of Shanxi Medical University, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Taiyuan, Shanxi, 030032, People’s Republic of China; 2The Fifth People’s Hospital of Datong, Datong, Shanxi Province, 037006, People’s Republic of ChinaCorrespondence: XiFeng Fu, Department of Biliary and Pancreatic Surgery, Third Hospital of Shanxi Medical University, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Taiyuan, 030032, People’s Republic of China, Email fxfyisheng@163.comBackground: Pancreatic cancer is a common malignant tumor. Multiple studies have shown that procollagen lysyl-hydroxylase (PLOD) family genes were closely related to tumor progression and metastasis in a variety of human cancers. This study aimed to explore the prognosis and biological role of PLOD family genes in pancreatic adenocarcinoma (PAAD).Methods: GEPIA, GEO, HPA, CCLE, Kaplan–Meier plotter, cBioPortal, LinkedOmics, DAVID6.8, STRING, and TIMER were employed to determine the prognostic values and biological function of PLOD family members in PAAD.Results: The mRNA and protein expression patterns of PLOD family members were noticeably up-regulated in PAAD compared with normal tissues. PLOD family gene expression was also up-regulated in pancreatic cancer cell lines. PLOD1 was correlated with histological and pathological grades of pancreatic cancer. PLOD2 was related to histological grade. The high expression of PLOD1-2 was correlated with the poor overall survival rate and relapse-free survival rate in patients with PAAD. Additionally, PLODs showed high sensitivity and specificity in distinguishing pancreatic cancer from normal tissues. Through the functional enrichment analysis of PLOD-related genes in PAAD, we found that PLODs were enriched in collagen fiber tissue structure, lysine degradation, and collagen biosynthesis. Pathway analysis confirmed that PLODs regulated the proliferation, migration, and metastasis of pancreatic cancer through the RalGEF-Ral signaling pathway. Furthermore, the level of expression of PLOD1-2 was positively correlated with the activity of tumor-infiltrating immune cells, including CD8+T cells, neutrophils, macrophages, and dendritic cells. The level of expression of PLOD3 was inversely correlated with the level of infiltration of CD8+T cells. PLOD1 and PLOD2 were highly expressed in pancreatic cancer tissues with TP53 and KRAS mutations, respectively. However, the level of expression of PLOD3 in SMAD4 wild-type pancreatic cancer was increased.Conclusion: The findings showed that individual PLOD genes or PLOD family genes could be potential prognostic biomarkers for PAAD.Keywords: PLOD, pancreatic cancer, prognosis, mutations, tumor-infiltrating immune cells

Sisi Mo,1– 3,&ast; Haiming Ru,1– 3,&ast; Maosen Huang,1– 3 Linyao Cheng,1– 3 Xianwei Mo,1– 3 Linhai Yan1– 3 1Department of Gastrointestinal Surgery, Guangxi Medical University Cancer Hospital, Nanning, 530021, Guangxi Zhuang Autonomous Region, People’s Republic of China; 2Guangxi Clinical Research Center for Colorectal Cancer, Nanning, 530021, Guangxi Zhuang Autonomous Region, People’s Republic of China; 3Guangxi Key Laboratory of Colorectal Cancer Prevention and Treatment, Nanning, 530021, Guangxi Zhuang Autonomous Region, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Linhai YanDepartment of Gastrointestinal Surgery, Guangxi Medical University Cancer Hospital, Hedi Road No. 71, Nanning, Guangxi Zhuang Autonomous Region, 530021, People’s Republic of China, Tel +86 139 78839969, Email lhyan@gxmu.edu.cnAbstract: It is widely recognized that microbial disorders are involved in the pathogenesis of many malignant tumors. The oral and intestinal tract are two of the overriding microbial habitats in the human body. Although they are anatomically and physiologically continuous, belonging to the openings at both ends of the digestive tract, the oral and intestinal microbiome do not cross talk with each other due to a variety of reasons, including intestinal microbial colonization resistance and chemical barriers in the upper digestive tract. However, this balance can be upset in certain circumstances, such as disruption of colonization resistance of gut microbes, intestinal inflammation, and disruption of the digestive tract chemical barrier. Evidence is now accruing to suggest that the oral microbiome can colonize the gut, leading to dysregulation of the gut microbes. Furthermore, the oral-gut microbes create an intestinal inflammatory and immunosuppressive microenvironment conducive to tumorigenesis and progression of colorectal cancer (CRC). Here, we review the oral to intestinal microbial transmission and the inflammatory and immunosuppressive microenvironment, induced by oral-gut axis microbes in the gut. A superior comprehension of the contribution of the oral-intestinal microbes to CRC provides new insights into the prevention and treatment of CRC in the future.Keywords: oral-intestinal microbiota, colorectal cancer, inflammatory microenvironment, immunosuppressive microenvironment

Shao-jian Mo,1 Hai-Chao Zhao,1 Yan-zhang Tian,2 Hao-Liang Zhao2 1Department of General Surgery, The Affiliated Bethune Hospital of Shanxi Medical University, Taiyuan 030032, People’s Republic of China; 2Department of General Surgery, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Taiyuan 030032, People’s Republic of ChinaCorrespondence: Yan-zhang TianDepartment of General Surgery, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Taiyuan 030032, People’s Republic of ChinaEmail tyz2030@163.comAbstract: Prefoldin (PFDN) is a hexameric chaperone complex that is widely found in eukaryotes and archaea and consists of six different subunits (PFDN1-6). Its main function is to transfer actin and tubulin monomers to the eukaryotic cell cytoplasmic chaperone protein (c-CPN) specific binding during the assembly of the cytoskeleton, to stabilize the newly synthesized peptides so that they can be folded correctly. The current study found that each subunit of PFDN has different functions, which are closely related to the occurrence, development and prognosis of tumors. However, the best characteristics of each subunit have not been fully affirmed. The connection between research and tumors can change the understanding of PFDN and further extend its potential prognostic role and structural function to cancer research and clinical practice. This article mainly reviews the role of canonical PFDN and its subunits in tumors and other diseases, and discusses the potential prospects of the unique structure and function of PFDN in nanomedicine.Keywords: prefoldin, disease, tumor, nanomedicine

COVID-19 has recently become one of the most challenging pandemics of the last century with deadly outcomes and a high rate of reproduction number. It emphasizes the critical need for the designing of efficient vaccines to prevent virus infection, early and fast diagnosis by the high sensitivity and selectivity diagnostic kits, and effective antiviral and protective therapeutics to decline and eliminate the viral load and side effects derived from tissue damages. Therefore, non-toxic antiviral nanoparticles (NPs) have been under development for clinical application to prevent and treat COVID-19. NPs showed great promise to provide nano vaccines against viral infections. Here, we discuss the potentials of NPs that may be applied as a drug itself or as a platform for the aim of drug and vaccine repurposing and development. Meanwhile, the advanced strategies based on NPs to detect viruses will be described with the goal of encouraging scientists to design effective and cost-benefit nanoplatforms for prevention, diagnosis, and treatment.

The incorporation of boron into a diamond lattice holds the potential to advance X-ray optics, offering the capability to manipulate various parameters of the lattice. This includes enhancing near-infrared absorption relative to pure diamond, thereby enabling Q-switchable optics. The use of MeV boron implantation emerges as a promising method for precisely doping the diamond lattice. However, for these optics to function effectively as Bragg-reflecting mirrors, ion implantation must be executed with meticulous attention to maintaining a strain-free, perfect diamond lattice. This study aimed to investigate the feasibility of utilizing a 9 MeV ion beam for high energy boron implantation. Different areas of a high-pressure, high-temperature (HPHT) diamond sample were subjected to irradiation with 9 MeV Boron ions, ranging in fluences from 5×1015 to 2.5×1016ions/cm2. Following boron implantation, high-temperature vacuum annealing was performed to restore the diamond lattice. Our assessment utilized X-ray rocking curve imaging, surface profilometry, and micro-Raman spectroscopy, with additional observations on near-infrared transmission properties. Our measurement of high-quality Bragg reflection through X-ray rocking curve imaging, sensitive to implantation-induced strain and defects, served as an key diagnostic for the effectiveness of this ion-implanted sample as a Bragg-reflecting optic.

Multi-trophic conservation and management strategies may be necessary if reciprocal linkages between primary producers and their consumers are strong. While herbivory on aquatic plants is well-studied, direct top-down control of seagrass populations has received comparatively little attention, particularly in temperate regions. Herein, we used qualitative and meta-analytic approaches to assess the scope and consequences of avian (primarily waterfowl) herbivory on temperate seagrasses of the genus Zostera. Meta-analyses revealed widespread evidence of spatio-temporal correlations between Zostera and waterfowl abundances as well as strong top-down effects of grazing on Zostera. We also documented the identity and diversity of avian species reported to consume Zostera and qualitatively assessed their potential to exert top-down control. Our results demonstrate that Zostera and their avian herbivores are ecologically linked and we suggest that bird herbivory may influence the spatial structure, composition, and functioning of the seagrass ecosystem. Therefore, the consequences of avian herbivory should be considered in the management of seagrass populations. Of particular concern are instances of seagrass overgrazing by waterfowl which result in long-term reductions in seagrass biomass or coverage, with subsequent impacts on local populations of waterfowl and other seagrass-affiliated species. While our results showed that bird density and type may affect the magnitude of the top-down effects of avian herbivory, empirical research on the strength, context-dependency, and indirect effects of waterfowl–Zostera interactions remains limited. For example, increased efforts that explicitly measure the effects of different functional groups of birds on seagrass abundance and/or document how climate change-driven shifts in waterfowl migratory patterns impact seagrass phenology and population structure will advance research programs for both ecologists and managers concerned with the joint conservation of both seagrasses and their avian herbivores.

EuTe4 is a van der Waals material exhibiting a charge density wave (CDW) with a large thermal hysteresis in the resistivity and CDW gap. In this paper, we systematically study the electronic structure and transport properties of EuTe4 using high-resolution angle-resolved photoemission spectroscopy (ARPES), magnetoresistance (MR) measurements, and scanning tunneling microscopy (STM). We observe a CDW gap of ∼200meV at low temperatures that persists up to 400 K, suggesting that the CDW transition occurs at a much higher temperature. The ARPES intensity near the Fermi level shows large thermal hysteretic behavior, consistent with the resistivity measurement. The hysteresis in the resistivity measurement does not change under a magnetic field up to 7 T, excluding the thermal magnetic hysteretic effect. Instead, the surface topography measured with STM shows surface domains with different CDW trimerization directions, which may be important for the thermal hysteretic behavior. Interestingly, we reveal a large negative MR at low temperatures that can be associated with the canting of magnetically ordered Eu spins. Our results shed light on the understanding of magnetic, transport, and electronic properties of EuTe4.

Electronic nematicity is a ubiquitous phenomenon in iron-based superconductors but its origin is still debated. Most models consider either spin or orbital degrees of freedom as the driving force but typically do not take electronic correlations into account. However, mass enhancements, coherent-incoherent crossovers, and the strong orbital differentiation can only be understood using correlations in a Hund's metal framework. Here, we study the influence of nematicity on the quasiparticle coherence in detwinned FeSe using angle-resolved photoemission spectroscopy (ARPES). We compare photoemission spectral weight from dxz and dyz orbitals in the coherent quasiparticle peak and in the incoherent Hubbard band and find an anisotropy between the two orbitals. We interpret our observation in terms of a more coherent dxz orbital compared to the dyz orbital inside the nematic phase. This result is in contrast to earlier predictions of an incoherent dxz orbital and highlights the importance of electronic correlations in the description of nematicity.

The hallmark of nematic order in iron-based superconductors is a resistivity anisotropy but it is unclear to which extent quasiparticle dispersions, lifetimes, and coherence contribute. While the lifted degeneracy of the Fe dxz and dyz dispersions has been studied extensively, only little is known about the two other factors. Here, we combine in situ strain tuning with ARPES and study the nematic response of the spectral weight in BaFe2As2. The symmetry analysis of the ARPES spectra demonstrates that the dxz band gains quasiparticle spectral weight compared to the dyz band for negative antisymmetric strain Δϵyy suggesting the same response inside the nematic phase. Our results are compatible with a different coherence of the dxz and dyz orbital within a Hund's metal picture. We also discuss the influence of orbital mixing.

The discovery of a two-dimensional electron gas (2DEG) at the [Formula: see text] interface has set a new platform for all-oxide electronics which could potentially exhibit the interplay among charge, spin, orbital, superconductivity, ferromagnetism and ferroelectricity. In this work, by using angle-resolved photoemission spectroscopy and conductivity measurement, we found the reduction of 2DEGs and the changes of the conductivity nature of some ferroelectric oxides including insulating Nb-lightly-substituted [Formula: see text], [Formula: see text] (BTO) and (Ca,Zr)-doped BTO across paraelectric-ferroelectric transition. We propose that these behaviours could be due to the increase of space-charge screening potential at the 2DEG/ferroelectric regions which is a result of the realignment of ferroelectric polarisation upon light irradiation. This finding suggests an opportunity for controlling the 2DEG at a bare oxide surface (instead of interfacial system) by using both light and ferroelectricity.

Light-sensitive capacitance variation of Bi0.95La0.05FeO3 (BLFO) ceramics has been studied under violet to UV irradiation. The reversible capacitance enhancement up to 21% under 405 nm violet laser irradiation has been observed, suggesting a possible degree of freedom to dynamically control this in high dielectric materials for light-sensitive capacitance applications. By using ultraviolet photoemission spectroscopy (UPS), we show here that exposure of BLFO surfaces to UV light induces a counterintuitive shift of the O2p valence state to lower binding energy of up to 243 meV which is a direct signature of negative electronic compressibility (NEC). A decrease of BLFO electrical resistance agrees strongly with the UPS data suggesting the creation of a thin conductive layer on its insulating bulk under light irradiation. By exploiting the quantum capacitance model, we find that the negative quantum capacitance due to this NEC effect plays an important role in this capacitance enhancement.

A number of rare-earth monopnictides have topologically nontrivial band structures together with magnetism and strong electronic correlations. In order to examine whether the antiferromagnetic (AFM) semimetal YbAs (TN=0.5 K) exhibits such a scenario, we have grown high-quality single crystals using a flux method, and characterized the magnetic properties and electronic structure using specific heat, magnetotransport, and angle-resolved photoemission spectroscopy (ARPES) measurements, together with density functional theory (DFT) calculations. Both ARPES and DFT calculations find no evidence for band inversions in YbAs, indicating a topologically trivial electronic structure. From low-temperature magnetotransport measurements, we map the field-temperature phase diagram, where we find the presence of a field stabilized phase distinct from the AFM phase at low temperatures. An extremely large magnetoresistance (XMR) for both YbAs and the nonmagnetic counterpart LuAs is also observed, which can consistently be accounted for by the presence of electron-hole compensation. Moreover, an angle-dependent study of the Shubnikov-de Haas effect oscillations reveals very similar Fermi surfaces between YbAs and LuAs, with light effective masses down to at least 0.5 K, indicating that the Yb-4f electrons are well localized, and do not contribute to the Fermi surface. However, the influence of the localized Yb-4f electrons on the magnetotransport of YbAs can be discerned from the distinct temperature dependence of the XMR compared to that of LuAs, which we attribute to the influence of short-ranged spin correlations that appear well above TN.

The chiral helimagnet Cr1/3NbS2 hosts exotic spin textures, whose influence on the magneto-transport properties make this material an ideal candidate for future spintronic applications. To date, the interplay between macroscopic magnetic and transport degrees of freedom is believed to result from a reduction in carrier scattering following spin order. Here, we present electronic structure measurements across the helimagnetic transition temperature TC that challenges this view. We show that the Fermi surface is comprised of strongly hybridized Nb- and Cr-derived electronic states, and that spectral weight close to the Fermi level increases anomalously as the temperature is lowered below TC. These findings are rationalized on the basis of first principle density functional theory calculations, which reveal a large nearest-neighbor exchange energy, suggesting the interaction between local spin moments and hybridized Nb- and Cr-derived itinerant states to go beyond the perturbative interaction of Ruderman-Kittel-Kasuya-Yosida, suggesting instead a mechanism rooted in a Hund’s exchange interaction.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Using high-resolution angle-resolved photoemission spectroscopy and ab initio calculation, we have studied the bulk and surface electronic structure of metallic rutile 5d transition metal oxide IrO2 that harbors both edge and corner sharing Ir-O octahedrons. We observe strong modulation of the band structure by spin-orbit coupling (SOC). The measured band structure is well reproduced by our ab initio calculation without band renormalization, suggesting the absence of the SOC-enhanced correlation effect in IrO2. In accordance with the calculation, we visualize two types of Dirac nodal lines (DNLs) protected by mirror symmetry and nonsymmorphic crystal symmetry, respectively. SOC gaps the first type of DNLs, which may contribute largely to the strong spin Hall effect. The second type of DNLs at the edges of Brillouin zone, however, remain intact against SOC. Our results not only provide important insights into the exotic transport properties of IrO2, but also shed light on the understanding of the role of SOC in the iridate family.

Single layers of transition metal dichalcogenides (TMDCs) are excellent candidates for electronic applications beyond the graphene platform; many of them exhibit novel properties including charge density waves (CDWs) and magnetic ordering. CDWs in these single layers are generally a planar projection of the corresponding bulk CDWs because of the quasi-two-dimensional nature of TMDCs; a different CDW symmetry is unexpected. We report herein the successful creation of pristine single-layer VSe_{2}, which shows a (sqrt[7]×sqrt[3]) CDW in contrast to the (4×4) CDW for the layers in bulk VSe_{2}. Angle-resolved photoemission spectroscopy from the single layer shows a sizable (sqrt[7]×sqrt[3]) CDW gap of ∼100  meV at the zone boundary, a 220 K CDW transition temperature twice the bulk value, and no ferromagnetic exchange splitting as predicted by theory. This robust CDW with an exotic broken symmetry as the ground state is explained via a first-principles analysis. The results illustrate a unique CDW phenomenon in the two-dimensional limit.

We investigate the hidden Berry curvature in bulk 2H-WSe_{2} by utilizing the surface sensitivity of angle resolved photoemission (ARPES). The symmetry in the electronic structure of transition metal dichalcogenides is used to uniquely determine the local orbital angular momentum (OAM) contribution to the circular dichroism (CD) in ARPES. The extracted CD signals for the K and K^{'} valleys are almost identical, but their signs, which should be determined by the valley index, are opposite. In addition, the sign is found to be the same for the two spin-split bands, indicating that it is independent of spin state. These observed CD behaviors are what are expected from Berry curvature of a monolayer of WSe_{2}. In order to see if CD-ARPES is indeed representative of hidden Berry curvature within a layer, we use tight binding analysis as well as density functional calculation to calculate the Berry curvature and local OAM of a monolayer WSe_{2}. We find that measured CD-ARPES is approximately proportional to the calculated Berry curvature as well as local OAM, further supporting our interpretation.

We report an angle-resolved photoemission spectroscopy study of the iron-based superconductor family, Ba_{1-x}Na_{x}Fe_{2}As_{2}. This system harbors the recently discovered double-Q magnetic order appearing in a reentrant C_{4} phase deep within the underdoped regime of the phase diagram that is otherwise dominated by the coupled nematic phase and collinear antiferromagnetic order. From a detailed temperature-dependence study, we identify the electronic response to the nematic phase in an orbital-dependent band shift that strictly follows the rotational symmetry of the lattice and disappears when the system restores C_{4} symmetry in the low temperature phase. In addition, we report the observation of a distinct electronic reconstruction that cannot be explained by the known electronic orders in the system.

By using angle-resolved photoemission spectroscopy (ARPES), the variation of the electronic structure of HfSe2 has been studied as a function of sodium intercalation. We observe how this drives a band splitting of the p-orbital valence bands and a simultaneous reduction of the indirect band gap by values of up to 400 and 280 meV, respectively. Our calculations indicate that such behavior is driven by the band deformation potential, which is a result of our observed strain induced by sodium intercalation. The applied uniaxial strain calculations based on density functional theory agree strongly with the experimental ARPES data. These findings should assist in studying the physical relationship between intercalation and strain, as well as for large-scale two-dimensional straintronics.

We report an optically induced reduction of the f-d hybridization in the prototypical heavy-fermion compound YbRh2Si2. We use femtosecond time- and angle-resolved photoemission spectroscopy to monitor changes of spectral weight and binding energies of the Yb 4f and Rh 4d states before the lattice temperature increases after pumping. Overall, the f-d hybridization decreases smoothly with increasing electronic temperature up to ∼250K but changes slope at ∼100K. This temperature scale coincides with the onset of coherent Kondo scattering and with thermally populating the first excited crystal electrical field level. Extending previous photoemission studies, we observe a persistent f-d hybridization up to at least ∼250K, which is far larger than the coherence temperature defined by transport but in agreement with the temperature dependence of the noninteger Yb valence. Our data underlines the distinction of probes accessing spin and charge degrees of freedom in strongly correlated systems.

The recent discovery of the extreme magnetoresistance (XMR) in the nonmagnetic rare-earth monopnictides LaX (X = P, As, Sb, Bi,), a recently proposed new topological semimetal family, has inspired intensive research effort in the exploration of the correlation between the XMR and their electronic structures. In this work, using angle-resolved photoemission spectroscopy to investigate the three-dimensional band structure of LaBi, we unraveled its topologically nontrivial nature with the observation of multiple topological surface Dirac fermions, as supported by our ab initio calculations. Furthermore, we observed substantial imbalance between the volume of electron and hole pockets, which rules out the electron-hole compensation as the primary cause of the XMR in LaBi.

A single monolayer of iron selenide grown on strontium titanate shows an impressive enhancement of superconductivity compared with the bulk, as well as a novel Fermi surface topology 2-5 , extreme two-dimensionality, and the possibility of phonon-enhanced electron pairing. For films thicker than one unit cell, however, the electronic structure is markedly different, with a drastically suppressed superconductivity and strong nematicity appearing 1,5 . The physics driving this extraordinary dichotomy of superconducting behaviour is far from clear. Here, we use low-temperature scanning tunnelling microscopy to study multilayers of iron selenide grown by molecular beam epitaxy, and find a stripe-type charge ordering instability that develops beneath the nematic state. The charge ordering is visible and pinned in the vicinity of impurities. And as it emerges in the strong limit of nematicity, it suggests that a magnetic fluctuation with a rather small wavevector may be competing with the ordinary collinear antiferromagnetic ordering in multilayer films. The existence of stripes in iron-based superconductors, which resemble the stripe order in cuprates, not only suggests that electronic anisotropy and correlation are playing an important role, but also provides a platform for probing the complex interactions between nematicity, charge ordering, magnetism and superconductivity in high-temperature superconductors.

Topological insulators represent unusual topological quantum states, typically with gapped bulk band structure but gapless surface Dirac fermions protected by time-reversal symmetry. Recently, a distinct kind of topological insulator resulting from nonsymmorphic crystalline symmetry was proposed in the KHgX (X=As, Sb, Bi) compounds. Unlike regular topological crystalline insulators, the nonsymmorphic glide-reflection symmetry in KHgX guarantees the appearance of an exotic surface fermion with hourglass shape dispersion (where two pairs of branches switch their partners) residing on its (010) side surface, contrasting to the usual two-dimensional Dirac fermion form. Here, by using high-resolution angle-resolved photoemission spectroscopy, we systematically investigate the electronic structures of KHgSb on both (001) and (010) surfaces and reveal the unique in-gap surface states on the (010) surface with delicate dispersion consistent with the "hourglass Fermion" recently proposed. Our experiment strongly supports that KHgSb is a nonsymmorphic topological crystalline insulator with hourglass fermions, which serves as an important step to the discovery of unique topological quantum materials and exotic fermions protected by nonsymmorphic crystalline symmetry.

Two-dimensional materials constitute a promising platform for developing nanoscale devices and systems. Their physical properties can be very different from those of the corresponding three-dimensional materials because of extreme quantum confinement and dimensional reduction. Here we report a study of TiTe2 from the single-layer to the bulk limit. Using angle-resolved photoemission spectroscopy and scanning tunneling microscopy and spectroscopy, we observed the emergence of a (2 × 2) charge density wave order in single-layer TiTe2 with a transition temperature of 92 ± 3 K. Also observed was a pseudogap of about 28 meV at the Fermi level at 4.2 K. Surprisingly, no charge density wave transitions were observed in two-layer and multi-layer TiTe2, despite the quasi-two-dimensional nature of the material in the bulk. The unique charge density wave phenomenon in the single layer raises intriguing questions that challenge the prevailing thinking about the mechanisms of charge density wave formation.Due to reduced dimensionality, the properties of 2D materials are often different from their 3D counterparts. Here, the authors identify the emergence of a unique charge density wave (CDW) order in monolayer TiTe2 that challenges the current understanding of CDW formation.