45 research outputs found
Electrical control and transport of tightly bound interlayer excitons in a MoSe2/hBN/MoSe2 heterostructure
Controlling interlayer excitons in van der Waals heterostructures holds
promise for exploring Bose-Einstein condensates and developing novel
optoelectronic applications, such as excitonic integrated circuits. Despite
intensive studies, several key fundamental properties of interlayer excitons,
such as their binding energies and interactions with charges, remain not well
understood. Here we report the formation of momentum-direct interlayer excitons
in a high-quality MoSe2/hBN/MoSe2 heterostructure under an electric field,
characterized by bright photoluminescence (PL) emission with high quantum yield
and a narrow linewidth of less than 4 meV. These interlayer excitons show
electrically tunable emission energy spanning ~180 meV through the Stark
effect, and exhibit a sizable binding energy of ~81 meV in the intrinsic
regime, along with trion binding energies of a few millielectronvolts.
Remarkably, we demonstrate the long-range transport of interlayer excitons with
a characteristic diffusion length exceeding ten micrometers, which can be
attributed, in part, to their dipolar repulsive interactions. Spatially and
polarization-resolved spectroscopic studies reveal rich exciton physics in the
system, such as valley polarization, local trapping, and the possible existence
of dark interlayer excitons. The formation and transport of tightly bound
interlayer excitons with narrow linewidth, coupled with the ability to
electrically manipulate their properties, open exciting new avenues for
exploring quantum many-body physics, including excitonic condensate and
superfluidity, and for developing novel optoelectronic devices, such as exciton
and photon routers.Comment: 4 figure
Correlation between visceral adiposity index and erectile dysfunction in American adult males: a cross-sectional study based on NHANES
BackgroundThe risk of visceral obesity on erectile function has recently attracted much attention. The visceral adiposity index (VAI) is a brief and reliable indicator of visceral obesity measurement. Nevertheless, the association between VAI and erectile dysfunction (ED) is not completely clarified.MethodsData from NHANES 2001â2004 were enrolled in this study. Erectile function was assessed by a database-self-administered questionnaire. VAI was calculated with body mass index (BMI), waist circumference (WC), triglyceride (TG), and high-density lipoprotein (HDL) cholesterol. The weighted logistic regression model was performed to evaluate the association between VAI and ED.ResultsUltimately, 3380 participants were enrolled in the study, including 900 with ED and 2480 without ED. Compared to participants without ED, those with ED generally had higher levels of VAI (1.76 vs. 1.53). The weighted logistic regression analyses demonstrated increased odds of developing ED in participants within the 4th quartile (Q4) of VAI compared to the 1st quartile (Q1) of VAI (OR = 2.023; 95% CI, 1.534â2.669; P < 0.001). Similar results were still obtained after adjusting for the relevant covariates (OR = 1.404; 95% CI, 1.008â1.954; P = 0.044). In subgroup analyses grouped by smoking status, higher VAI was associated with increased odds of developing ED only in the current smoking group (OR = 1.092; 95% CI, 1.021â1.167; P = 0.010).ConclusionThis study indicated that higher VAI is independently related to ED risk and that early intervention is necessary to reduce the progression of ED with high VAI levels
Excitonic Mott insulator in a Bose-Fermi-Hubbard system of moir\'e / heterobilayer
Understanding the Hubbard model is crucial for investigating various quantum
many-body states and its fermionic and bosonic versions have been largely
realized separately. Recently, transition metal dichalcogenides heterobilayers
have emerged as a promising platform for simulating the rich physics of the
Hubbard model. In this work, we explore the interplay between fermionic and
bosonic populations, using a / heterobilayer device that
hosts this hybrid particle density. We independently tune the fermionic and
bosonic populations by electronic doping and optical injection of electron-hole
pairs, respectively. This enables us to form strongly interacting excitons that
are manifested in a large energy gap in the photoluminescence spectrum. The
incompressibility of excitons is further corroborated by measuring exciton
diffusion, which remains constant upon increasing pumping intensity, as opposed
to the expected behavior of a weakly interacting gas of bosons, suggesting the
formation of a bosonic Mott insulator. We explain our observations using a
two-band model including phase space filling. Our system provides a
controllable approach to the exploration of quantum many-body effects in the
generalized Bose-Fermi-Hubbard model.Comment: Main text: 7 pages, 5 figures. Supplementary Material: 10 pages, 7
figure
Combustion Enhancement of Pulverized Coal with Targeted Oxygen-Enrichment in an Ironmaking Blast Furnace
In this study, a targeted oxygen-enrichment technology was proposed to enhance coal combustion in an ironmaking blast furnace. The coal flow and combustion characteristics under targeted oxygen-enrichment were investigated using the computational fluid dynamics (CFD) method. The results showed that oxygen utilization and coal burnout were significantly increased under targeted oxygen-enrichment. The coal burnout at 24% O2 concentration was 86.29%, which was the maximum and indicated an increase of 13.13%. However, the cooling effect of room-temperature oxygen had some adverse effects on coal combustion. Given this, the effect of coal particle temperature on coal combustion was investigated based on targeted oxygen-enrichment. The coal combustion process was further enhanced. The coal burnout at a 600 K particle temperature and 25% oxygen concentration was 91.12% and had an increase of 17.96%, which was the maximum
Modified anterior approach versus traditional posterior approach for ultrasound-guided superior laryngeal nerve block in awake endotracheal intubation: a randomized non-inferiority clinical trial
AbstractStudy objective This study was undertaken to compare the effect of the modified ultrasound-guided anterior superior laryngeal nerve block (SLNB) with the traditional ultrasound-guided posterior SLNB in providing intubation conditions during awake tracheal intubation (ATI) in patients without difficult airway.Design Randomized, assessor-blind. Registration number: ChiCTR2200058086.Setting West China Hospital of Sichuan University, Chengdu, China.Patients 104 patients aged 18â65âyears, of American Society of Anesthesiologists status I-III, posted for elective general surgery with general endotracheal anesthesia.Interventions The patients were randomized into two groups (modified group, nâ=â52; traditional group, nâ=â52). Modified anterior SLNB or traditional posterior SLNB was performed under ultrasound guidance.Measurements The primary outcome was the proportion of acceptable intubation condition (AIC), which was analyzed in both per-protocol (PP) and intention-to-treat (ITT) populations. The prespecified non-inferiority margin was â4.8%. Secondary outcomes included intubation success rate on the first attempt, hemodynamic parameters during ATI, time taken for airway anesthesia and intubation, recall of intubation, patient perception of comfort, and incidence and severity of postoperative complications.Main results In the PP population, the proportion of AIC in the modified group was 49/49 (100%) and that in the traditional group was 49/49 (100%), absolute difference 0, lower limit of 1-sided 95% CI, â0.3%. In the ITT population, the primary outcomes in the modified and traditional group were 52/52 (100%) and 51/52 (98.1%), respectively, with an absolute difference of 1.9% and a lower limit of 1-sided 95% CI of â1.2%. The non-inferiority of modified ultrasound-guided anterior SLNB was confirmed in both populations.Conclusions Among adults without difficult airways during videolaryngoscope-assisted ATI, the modified ultrasound-guided anterior SLNB, compared to the traditional posterior approach, showed a statistically non-inferior effect in terms of providing AIC
Numerical Investigation on Coal Combustion in Ultralow CO2 Blast Furnace: Effect of Oxygen Temperature
The cooling effect of room-temperature oxygen in oxygen blast furnaces with top gas recycling (TGR-OBF) delays the coal combustion process. To further explore the oxygen–coal combustion mechanism and intensify coal combustion in TGR-OBF, the effect of oxygen temperature on coal combustion was investigated using computational fluid dynamics (CFD). A three-dimensional model was developed to simulate the lance–blowpipe–tuyere–raceway of TGR-OBF. The effect of oxygen temperature at the same oxygen velocity and mass flow on coal combustion was investigated. Results showed the cooling effect of room-temperature oxygen was weakened, and the coal burnout was greatly increased with the increase in oxygen temperature. In particular, the coal burnout increased from 21.64% to 81.98% at the same oxygen velocity when the oxygen temperature increased from 300 to 500 K. The results provide useful reference for the development of TGR-OBF and coal combustion technology
Knowledge mapping and research hotspots of artificial intelligence on ICU and Anesthesia: from a global bibliometric perspective
Abstract The swift advancement of technology has led to the widespread utilization of artificial intelligence (AI) in the diagnosis of diseases and prediction of prognoses, particularly in the field of intensive care unit (ICU) and Anesthesia. Numerous evidential data have demonstrated the extensive potential of AI in monitoring and predicting patient outcomes in these fields. Using bibliometric analysis, this study provides an overview of the current state of knowledge regarding the application of AI in ICU and Anesthesia and investigates prospective avenues for future research. Web of Science Core Collection was queried on May 6, 2023, to select articles and reviews regarding AI in ICU and Anesthesia. Subsequently, various analytical tools including Microsoft Excel 2022, VOSviewer (version 1.6.16), Citespace (version 6.2.R2), and an online bibliometric platform were employed to examine the publication year, citations, authors, countries, institutions, journals, and keywords associated with this subject area. This study selected 2196 articles from the literature. focusing on AI-related research within the fields of ICU and Anesthesia, which has increased exponentially over the past decade. Among them, the USA ranked first with 634 publications and had close international cooperation. Harvard Medical School was the most productive institution. In terms of publications, Scientific Reports (impact factor (IF) 4.996) had the most, while Critical Care Medicine (IF 9.296) had the most citations. According to numerous references, researchers may focus on the following research hotspots: âEarly Warning Scoresâ, âCovid-19âł, âSepsisâ and âNeural Networksâ. âProcalcitoninâ and âConvolutional Neural Networksâ were the hottest burst keywords. The potential applications of AI in the fields of ICU and Anesthesia have garnered significant attention from scholars, prompting an increase in research endeavors. In addition, it is imperative for various countries and institutions to enhance their collaborative efforts in this area. The research focus in the upcoming years will center on sepsis and coronavirus, as well as the development of predictive models utilizing neural network algorithms to improve well-being and quality of life in surviving patients. Graphical Abstrac
Abnormal sleep duration is associated with sarcopenia in older Chinese people: A large retrospective cross-sectional study
Abnormalities in sleep patterns are a common health problem for the older adults. The relationship between sarcopenia and sleep duration in older people is controversial. This research is to examine the association between sleep duration and sarcopenia
Development of Multiscale Transcriptional Regulatory Network in Esophageal Cancer Based on Integrated Analysis
Objective. To explore multiscale integrated analysis methods in identifying key regulators of esophageal cancer (ESCA). Methods. We downloaded the ESCA dataset from The Cancer Genome Atlas (TCGA) database, which contained RNA-seq data, miRNA-seq data, methylation data, and clinical phenotype information. Then, we combined ESCA-related genes from the NCBI-GENE and OMIM databases and RNA-seq dataset from TCGA to analyze differentially expressed genes (DEGs). Meanwhile, differentially expressed miRNAs (DEmiRNAs) and genes with differential methylation levels were identified. The pivotâmodule pairs were established using the RAID v2.0 database and TRRUST v2 database. Next, the multifactor-regulated functional network was constructed based on the above information. Additionally, gene corresponding targeted drug information was obtained from the DrugBank database. Moreover, we further screened regulators by assessing their diagnostic value and prognostic value, especially the value of distinguishing patients at TNM I stage from normal patients. In addition, the external database from the Gene Expression Omnibus (GEO) database was used for validation. Lastly, gene set enrichment analysis (GSEA) was performed to explore the potential biological functions of key regulators. Results. Our study indicated that CXCL8, CYP2C8, and E2F1 had excellent diagnostic and prognostic values, which may be potential regulators of ESCA. At the same time, the good early diagnosis ability of the three regulators also provided new insights for the diagnosis and early treatment of ESCA patients. Conclusion. We develop a multiscale integrated analysis and suggest that CXCL8, CYP2C8, and E2F1 are promising regulators with good diagnostic and prognostic values in ESCA