Browse Articles

Electron correlation in benzene: A QMC study of neutral and charged states

In this paper, we employ variational Monte Carlo and fixed-node diffusion Monte Carlo (FN-DMC) methods to investigate electron correlation effects in neutral and charged benzene molecules. Using orbitals from Hartree–Fock (HF) and density functional theory calculations, FN-DMC with the frozen-core approximation yields correlation energies consistent with CCSD(T) and ph-AFQMC, while all-electron FN-DMC lowers the correlation energy by ∼0.27 a.u., highlighting the role of core-electron contributions. On average, all-electron FN-DMC predicts vertical [VIP: 0.3477(34) a.u.] and adiabatic [AIP: 0.3433(39) a.u.] ionization potentials, both slightly above the experimental value [0.339 70(2) a.u.]. Zero-point vibrational energy (ZPVE) corrections adjust the VIP and AIP by −0.012 and +0.0037 a.u., respectively, improving agreement with experiment. Compared to HF, FN-DMC incorporates an additional 0.055 a.u. (≈1.5 eV) of correlation energy into the IP, demonstrating its effectiveness in capturing electron correlation in aromatic systems.

Evaluating the accuracy of ICD-10 codes for syncytial respiratory virus diagnosis in hospitalized patients: A record-linkage study (2022–2023)

Background Respiratory Syncytial Virus (RSV) is a leading cause of severe respiratory infections in young children and older adults. Accurate RSV surveillance is essential to understanding its disease burden and evaluating vaccine impact. Methods We assessed the accuracy of ICD-10 coding for RSV hospitalizations in the Brazilian Hospital Information System (SIH) by linking it with the Severe Acute Respiratory Syndrome (SIVEP) notification system (2022–2023). Laboratory-confirmed RSV-positive and RSV-negative cases in SIVEP were used as the reference standard. Sensitivity and specificity were evaluated for ICD-10 definitions (RSV, RSV +  J21 [Acute Bronchiolitis], RSV +  Acute Respiratory Infection) overall and by age group (under 1 year, under 5 years, and over 60 years). The top 10 diagnoses of RSV-positive patients were also analyzed by age group. Results Among 15,169 RSV-positive patients linked to an SIH record, 73.0% were under 12 months old, 20.8% were 1-5 years old, 3.7% were 5-59 years old, and 2.5% were 60 + years. Acute bronchiolitis was the most common diagnosis overall (43.5%), particularly in infants (53.5%). In older adults, pneumonia due to unspecified microorganisms was most frequent (24.6%). Sensitivity improved with broader case definitions, such as, RSV +  Acute Respiratory Infection (66.7%, 95%CI: 65.8–67.6 in infants; 23%, 95%CI: 18.9–27.6 in older adults). Specificity was higher in older adults (83.8%, 95%CI: 83.5–84.1) than in infants (45.1%, 95%CI: 44.4–45.6). Additionally, 40,701 RSV-positive notified cases lacked RSV-coded diagnoses in SIH. Conclusion Our study highlights the discrepancy between RSV-positive cases identified in SIVEP and those coded in the SIH database, reflecting limitations in ICD-10 coding, particularly in the older population. Reliance on symptomatic coding rather than confirmed diagnoses contributes to this issue. Accurate RSV identification is crucial, especially with new vaccines available. Improved diagnostic coding is essential for effective RSV surveillance and evaluating vaccine impact.

Impact of iodine-substitution on the symmetry and room-temperature phosphorescence behavior of thienyl diketone skeleton

Introducing heavy atoms, or replacing atoms with heavier ones, is a routine approach for accelerating spin-flipping photophysical processes. However, predicting its impact on phosphorescence efficiency is not straightforward. Herein, we report an unexpected consequence of bromine-to-iodine substitution in a bromothienyl diketone derivative, TIPS-BrTn, that exhibits outstanding room-temperature phosphorescence (RTP) in cyclohexane solution. Contrary to our expectation, the iodo-congener TIPS-ITn exhibited feeble photoluminescence, which we confirmed as RTP by ultrafast spectroscopy. Further experimental and theoretical studies revealed that, in the T1 state, an excited-state symmetry breaking occurred on TIPS-ITn while TIPS-BrTn preserved the centrosymmetric geometry. We identified the driving force for the symmetry breaking as an intramolecular two-center three-electron bonding interaction between iodine and carbonyl oxygen in the (n,π*) excited state. Consequently, while the direct T1–S0 spin–orbit coupling (SOC) in TIPS-BrTn is symmetry-forbidden and zero, that of TIPS-ITn is non-zero due to the loss of centrosymmetry, thereby accelerating nonradiative T1–S0 decay to diminish the RTP. Importantly, the phosphorescence rate constant is not solely dictated by the direct T1–S0 SOC; instead, it can be rationalized by the intensity borrowing from higher singlet states. Thus, our work highlights the importance of controlling molecular symmetry, which could suppress the direct T1–S0 SOC and lead to a preferential acceleration of radiative decay over nonradiative decay for achieving efficient RTP.

Metabolic improvement after exercise training in children with obesity: Possible role of the six-minute walking test

The aims of this study are to evaluate the effectiveness of an online supervised training program in modulating lipid and glucose metabolism in children with obesity and to investigate the possible role of the 6-minute walking test (6MWT) as a predictor of metabolic improvement. A total of 35 Caucasian children with obesity (aged 8-13) were enrolled in the study and tested before (T0) and after (T1) a 12-week online supervised exercise training protocol: cardiovascular fitness (by means of 6MWT), metabolic biochemical profile, lifestyle (with ad hoc questionnaires focusing on physical activity, nutrition, sedentariness, sleep hours and quality, health perception) and Cardiac Autonomic Regulation (CAR) were assessed. Spearman correlations between the variations in the studied outcomes were explored. After intervention, the distance covered during 6MWT significantly increased (p < 0.001), and nutrition quality improved slightly but significantly (p = 0.03). The improvement in the 6MWT performance was shown to be significantly correlatee with the reduction of insulin levels (r = -0.455; p = 0.02), HOMA-IR Index (r = -0.452; p = 0.02), total cholesterol values (r = -0.549; p = 0.004) and Atherogenic Index of Plasma (AIP) (r = 0.422; p = 0.04). Moreover, there was a significant correlation between the improvement in 6MWT and health perception (r = 0.578; p = 0.002). We observed that the improvement in the 6MWT performance correlates with better metabolic profile after exercise training in children with obesity suggesting the goodness of this simple test on unveil changes in pathogenetic processes underlying obesity.

Ehrenfest dynamics with localized atomic-orbital basis sets within the projector augmented-wave method

Density functional theory with linear combination of atomic orbitals (LCAO) basis sets is useful for studying large atomic systems, especially when it comes to computationally highly demanding time-dependent dynamics. We have implemented the Ehrenfest molecular dynamics (ED) method with the approximate approach of Tomfohr and Sankey within the projector augmented-wave code GPAW. We apply this method to small molecules as well as larger periodic systems and elucidate its limits, advantages, and disadvantages in comparison with the existing implementation of Ehrenfest dynamics with a real-space grid representation. For modest atomic velocities, LCAO-ED shows satisfactory accuracy at a much reduced computational cost. This method will be particularly useful for modeling ion irradiation processes that require large amounts of vacuum in the simulation cell.

Correction: Effects of Yersinia pseudotuberculosis outer membrane vesicles on Pseudomonas aeruginosa antigens immune response

Molecular dynamics simulations for enzymatic hydride-transfer reactions: Defining environmental reaction coordinates to capture transition state diversity

It is now well established that the transition state of a chemical reaction is not a single, static structure but rather a distribution of configurations. However, the implications of this distributed nature remain incompletely characterized, particularly for quantum proton and hydride transfer reactions, where variations in donor–acceptor separations at the transition state are key: they can determine whether or not tunneling contributes to the transfer. Consequently, the transition state’s characterization critically depends on the chosen reaction coordinate, and several geometry-based and energy-based coordinates have been proposed for empirical valence bond and hybrid QM/MM molecular dynamics simulations of such reactions. Here, we systematically evaluate these coordinates, using a general analytic model for proton- and hydride-transfer reactions alongside important aspects of the enzymatic hydride transfer in formate dehydrogenase as a case study. Our analysis reveals significant limitations of common geometry-based and vertical energy gap coordinates, which often fail to isolate environmental effects and can bias the description of transition states. To address these issues, we propose an equilibrium energy difference coordinate that excludes the rapid fluctuations of the transferring quantum proton or hydride, focusing instead on the environment’s polarization. Additionally, we demonstrate that the broad distribution of transition state configurations implies that key reaction properties, such as rate constants and kinetic isotope effects, may not always report on the same subset of transition state configurations. This insight helps resolve some mechanistic ambiguities and highlights the importance of carefully selecting reaction coordinates for simulating reaction dynamics (especially for quantum particle transfers) in enzymatic and condensed-phase chemistry.

Extraordinary siblings: Mole rats, marmosets, and Radcliffe-Brown

According to the theory of kin selection, an organism that shows some level of altruism toward her kin – lowering her own fitness, raising that of a close genetic relative – may enjoy an evolutionary advantage. Some species show beyond-ordinary altruism toward siblings, and other kin, owing to unusual reproductive biology and/or ecology. Human beings are exceptional in another way: how we treat our kin depends partly on how we feel about them, but also partly on socially enforced norms. This article explores several versions of a simple evolutionary game, the Brothers Karamazov Game, that departs from the standard theory of kin selection to allow for the distinctively human capacity for establishing and enforcing social norms. We discuss possible applications to understanding the “unity of the sibling group” (Radcliffe-Brown) – according exceptional treatment to siblings, and to relatives classified as siblings or linked through siblings. We give special attention to lowland South America, where the sibling relationship is central to social organization.

Trajectory-based non-adiabatic simulations of the polariton relaxation dynamics

We benchmark the accuracy of various trajectory-based non-adiabatic methods in simulating the polariton relaxation dynamics under the collective coupling regime. The Holstein–Tavis–Cummings Hamiltonian is used to describe the hybrid light–matter system of N molecules coupled to a single cavity mode. We apply various recently developed trajectory-based methods to simulate the population relaxation dynamics by initially exciting the upper polariton state and benchmark the results against populations computed from exact quantum dynamical propagation using the hierarchical equations of motion approach. In these benchmarks, we have systematically varied the number of molecules N, light–matter detunings, and the light–matter coupling strengths. Our results demonstrate that the symmetrical quasi-classical method with γ correction and spin-mapping linearized semi-classical approaches yield more accurate polariton population dynamics than traditional mixed quantum-classical methods, such as the Ehrenfest and surface hopping techniques.

A quality improvement initiative to increase HIV post-exposure prophylaxis treatment for emergency department patients after sexual assault: A pre-post study

Background Many emergency department (ED) patients after a sexual assault face barriers to receiving HIV post-exposure prophylaxis (PEP). We implemented a quality improvement initiative which updated the sexual assault electronic health record (EHR) template and made available free, full-course PEP treatment packs for use at provider discretion. The aim of this study was to compare the receipt of HIV PEP for ED patients receiving sexual assault care before and after the initiative. Methods This was a retrospective, quasi-experimental, pre-post study of all ED patients who completed a sexual assault examination between June 1, 2022 – January 31, 2023 (pre-intervention) and March 1, 2023 – October 31, 2023 (post-intervention). An odds ratio (OR) and 95% confidence interval (CI) were calculated to determine the initiative’s effect on PEP prescribing. Multivariable logistic regression models estimated the independent effect of the initiative while controlling for potential confounders. Results Of the 235 sexual assault examinations, 117 (49.8%) were during the pre-intervention and 118 (50.2%) were during the post-intervention periods. Pre-intervention, the mean age was 33.0 years (standard deviation [SD] 12.3), 94.0% were female, 30.8% Black, 31.6% Latinx, and 28.2% White. Post-intervention, the mean age was 29.2 years (SD 12.6), 90.7% were female, 42.4% Black, 28.8% Latinx, and 17.8% White. Patients were more likely to receive HIV PEP post-intervention (33/118, 28.0%) than pre-intervention (11/117, 9.4%) (OR 3.7, 95% CI 1.8 to 7.8). The independent effect of the initiative on HIV PEP prescribing remained significant after controlling for demographics (OR 3.6, 95% CI 1.6 to 8.0), assault characteristics (OR 4.2, 95% CI 1.6 to 11.1), and provider experience (OR 3.5, 95% CI 1.7 to 7.5). Conclusion The availability of HIV PEP treatment packs plus a modification to the EHR template led to a significant increase in the provision of HIV PEP for ED patients after sexual assault.

Deciphering the structural code for the face-centered-cubic ligand protected intermetallic AuAg nanoclusters

The incorporation of Ag atoms into ligand-protected gold nanoclusters is an effective way to tune their properties for applications in optics, electronics, and catalysis. However, the precise identification of preferred doping sites is challenging owing to its high structural complexity, which hinders establishing the structure–activity relationship. Here, through density functional theory calculations coupled with energy evaluation, delicate structural analysis, valence electron counting, and localized molecular orbital topology, we characterize the tetrahedral Au3Ag with closed-shell two valence electrons [Au3Ag(2e)] as a fundamental building block in face-centered-cubic (FCC) ligand-protected AuAg (LP-AuAg) alloy nanoclusters. The kernel structures of FCC LP-AuAg alloy clusters are constructed by rational spatial packing of Au3Ag(2e), Au4(2e), and Au3(2e) blocks, aligning with the grand unified model of ligand-protected Au nanoclusters. In addition, we predict 40 FCC LP-AuAg alloy nanoclusters with 141 low-energy isomers. This work underscores the crucial role of subset blocks in stabilizing the entire cluster and provides valuable insights into the structural features of FCC LP-AuAg alloy clusters.

Associated factors, triggers and long-term outcome in Complex Regional Pain Syndrome (CRPS) in the upper limb – A descriptive cross-sectional study

The pathophysiology behind Complex Regional Pain Syndrome (CRPS) is not fully understood and associated factors and triggers for developing the condition are debated. We aimed to study such factors and long-term outcome in a descriptive cross-sectional study with a well-defined population with CRPS in the upper limb and related to sex and CRPS type. In retrospectively collected data from medical records, 149 subjects [women n = 104 (70%); type 1 CRPS, n = 108 (72%); type 2 CRPS, n = 41 (28%); follow-up time 21 [8-43] months] were identified and analysed (Chi-squared test, Mann-Whitney U-test, and multiple linear regression). A majority were manual workers, and a larger proportion of subjects were smokers and had less post-secondary education than a reference population (p < 0.001 and p < 0.008). Men were younger, more frequently smoked, had higher BMI, and had lower education levels than women (p = 0.044, p = 0.007, p < 0.001, and p = 0.016, respectively). Subjects with CRPS type 2 were younger and had a longer time from symptoms until diagnosis, longer follow-up time, and more follow-up visits, indicating worse outcome (p = 0.016, p = 0.0012, p = 0.003, and p = 0.004, respectively). Among CRPS, 32% had a prior pain disorder and 7% had previously visited a pain management clinic. While there was no significant difference in mental illness occurrence before CRPS diagnosis compared to a reference population, mental illness increased by 76% after diagnosis. Factors such as CRPS type 2, older age, and delayed diagnosis were associated with longer follow-up periods. Additionally, 45% were on sick leave for over 12 months, and 20% were permanently unable to work. Socioeconomic deprivation is an associated factor in developing CRPS, in which a variety of triggers exist. Subjects with CRPS, particularly type 2, are at high risk of severe remaining symptoms, including mental illness and risk of never returning to work.

Heteroatom decorated C2N monolayer for gas-sensing application: Insight from first-principles

Development of novel gas-sensing materials is essential to high-performance gas sensors for monitoring target gases in industrial production and environmental protection. Herein, we investigate two types of the heteroatom-decorated C2N monolayer, denoted as M@C2N (M = Mn and Ni) and B-C2N, for their gas-sensing functionality toward seven small gaseous molecules (H2, O2, N2, CO, CO2, NH3, and H2O). The key gas-sensing characteristics concerning chemiresistive (CR) and field-effect transistor (FET) gas sensing have been thoroughly explored. The results show that Mn@C2N and Ni@C2N can work as either CR or FET gas-sensing materials for detecting H2, O2, N2, CO, CO2, NH3, and H2O, whereas B-C2N can work as a disposable gas sensor for O2, H2O, and NH3. Mn@C2N and Ni@C2N are the most selective toward O2 and NH3, followed by CO and H2O in an oxygen- and ammonia-free environment, while B-C2N is the most selective toward H2O and NH3. More importantly, the adsorption strength of target molecule plays a critical role in gas-sensing mechanism as well as selectivity, recovery time, and sensitivity. This study offers theoretical perspectives on 2D hybrid carbon-based nanomaterials for efficient gas sensing.

Role of aspirin on colorectal cancer risk and bacterial translocation to bloodstream

An involvement of gut microbiota on the possible role of aspirin against intestinal adenoma (IA) and colorectal cancer (CRC) has been suggested. To further investigate this issue, we analyzed data from an Italian case-control study including 100 incident histologically confirmed CRC cases, as well as 100 IA and 100 controls without lesions from colonoscopy, matched to cases by center, sex and age. Serum zonulin was assessed by ELISA kit and blood bacterial DNA by qPCR and 16S rRNA gene profiling. Fifty-eight subjects (19.3%) reported aspirin use of ≥  100 mg/day for cardiovascular prevention for at least six months. To evaluate the relationship between aspirin and IA and CRC risks, the odds ratios (OR) of IA and CRC and the corresponding 95% confidence intervals (CI) for aspirin use were estimated using a logistic regression model conditioned on the matching variable and adjusted for education and a model adjusted for several potential confounders including BMI and cardiovascular diseases. We evaluated whether the levels of zonulin and bacterial DNA data were different in aspirin users vs non-users through the rank sum and chi-square tests. Aspirin use was associated with a reduced risk of IA (OR = 0.45, 95% CI = 0.21-0.94) and CRC (OR = 0.43, 95% CI = 0.19-0.96). Similar results were obtained using the fully adjusted model. We found lower genera and operational taxonomic units (OTUs) richness of blood bacterial community in aspirin users vs non-users overall and in cases and controls. The genera Cutibacterium, Sphingomonas, Gaiella, Delftia and Romboutsia, order Microtrichales and class Deltaproteobacteria were different according to aspirin use. This study provides additional data on the favorable role of aspirin on IA and CRC risks and supports the hypothesis of an involvement of intestinal bacterial translocation to the bloodstream.

Transient absorption and anisotropy studies of a push–pull azo derivative with an isomerization path-selective local minimum in the ground state

The ultrafast excited-state dynamics of the E and Z isomers of a push–pull nitroazobenzene containing an octupolar bis(4′-tert-butylbiphenyl-4-yl)aminophenyl electron donor group were studied with transient absorption (TA) and TA anisotropy. A comprehensive study with two excitation wavelengths and a broadband white-light continuum probe (400–1400 nm) has determined that a torsional isomerization mechanism is the most probable for both isomers. This has shed light on the excited state behavior of the elusive push–pull Z isomer, which has its properties mostly predicted by simulations and systematically lacks experimental observations. Meanwhile, another unproductive relaxation pathway, associated with a symmetric bending motion, was found only for the E isomer. When relaxing through this pathway, the molecule encounters a potential barrier in the ground state, which requires significant structural reorganization before full relaxation. This local minimum can be more general than expected and may be behind unsolved issues in the literature of azobenzenes.

Effect of pyrroloquinoline quinone on skin aging in Bmi-1 KO mice and underlying mechanisms

To investigate the effect of pyrroloquinoline quinone (PQQ) on skin aging in the Bmi-1 KO mice and its underlying mechanisms, we administered a normal diet to both Wild type mice (WT) and Bmi-1 KO mice, while supplementing the diet of Bmi-1 KO mice with PQQ (PQQ+Bmi-1 KO). Subsequently, we compared the thickness of the skin epidermis, dermis, pilosebaceous unit and collagen ratio using HE staining and Masson’s trichrome. Additionally, immunohistochemical staining, Western blotting and electron microscopy were applied across all three groups. The results revealed that Bmi-1 KO mice exhibited premature aging phenotypes compared to the WT group; however, PQQ administration effectively delayed premature aging in Bmi-1 KO mice. Furthermore, reduced epidermal thickness, dermal thickness, pilosebaceous units count as well as collagen ratio were observed in Bmi-1 KO mice. Moreover, the PCNA positive cell percentage also decreased in Bmi-1 KO mice. Conversely, treatment with PQQ significantly increased epidermal thickness, dermal thickness, pilosebaceous unit count, collagen ratio and PCNA positive cell percentage when compared to Bmi-1 KO mice. In order to further investigate the anti-aging mechanism of PQQ, experiments have revealed that PQQ effectively suppressed the expression of cell cycle proteins p16, p19, and p53 in Bmi-1 KO mice. In addition, autophagy-related experiments demonstrated that compared to the WT group, Bmi-1 KO mice exhibited an increased number of autophagosomes along with decreased expression of Beclin-1 and LC3Ⅱ/LC3Ⅰratio, and increased expression of p62. However, supplementation with PQQ resulted in a reduction in the number of autophagosomes while increasing the expression of Beclin-1 and LC3Ⅱ/LC3Ⅰratio and decreasing the expression of p62. This study provides evidence that downregulation of Bmi-1 promotes skin aging, whereas PQQ delays skin aging in Bmi-1 KO mice by promoting cell proliferation, inhibiting the expression of p16, p19 and p53 and enhancing autophagy levels.

Understanding dynamics in coarse-grained models. V. Extension of coarse-grained dynamics theory to non-hard sphere systems

Coarse-grained (CG) modeling has gained significant attention in recent years due to its wide applicability in enhancing the spatiotemporal scales of molecular simulations. While CG simulations, often performed with Hamiltonian mechanics, faithfully recapitulate structural correlations at equilibrium, they lead to ambiguously accelerated dynamics. In Paper I [J. Jin, K. S. Schweizer, and G. A. Voth, J. Chem. Phys. 158(3), 034103 (2023)], we proposed the excess entropy scaling relationship to understand the CG dynamics. Then, in Paper II [J. Jin, K. S. Schweizer, and G. A. Voth, J. Chem. Phys. 158(3), 034104 (2023)], we developed a theory to map the CG system into a dynamically consistent hard sphere system to analytically derive an expression for fast CG dynamics. However, many chemical and physical systems do not exhibit hard sphere-like behavior, limiting the extensibility of the developed theory. In this paper, we aim to generalize the theory to the non-hard sphere system based on the Weeks–Chandler–Andersen perturbation theory. Since non-hard sphere-like CG interactions affect the excess entropy term as it deviates from the hard sphere description, we explicitly account for the extra entropy to correct the non-hard sphere nature of the system. This approach is demonstrated for two different types of interactions seen in liquids, and we further provide a generalized description for any CG models using the generalized Gaussian CG models using Gaussian basis sets. Altogether, this work allows for extending the range and applicability of the hard sphere CG dynamics theory to a myriad of CG liquids.

Correction: Detection and recognition of foreign objects in Pu-erh Sun-dried green tea using an improved YOLOv8 based on deep learning

Thermostatting nonequilibrium systems: A thermal energy constraint for systems under directive perturbations

This paper brings attention back to discussions about the use of equilibrium thermostats for nonequilibrium molecular dynamics simulations. It argues that, due to the fluctuation–dissipation theorem, the justification for using equilibrium thermostats for nonequilibrium simulations is inherited only by cases in which the perturbation is small enough for the perturbed system to behave like the unperturbed equilibrium system. In the process, this paper categorizes models of external perturbations in molecular dynamics as either responsive—i.e., perturbations that impose a force—or directive—i.e., perturbations that impose a trajectory. Since directive perturbations have not been studied enough in the literature but are becoming more relevant, their effects on simple perturbed thermostatted systems are considered. Finally, using a perturbed two-point harmonic oscillator as well as a driven particle immersed in a simple Lennard-Jones fluid, it gives an approximation for the limit of justified equilibrium thermostat use for perturbed systems. This paper hopes to inspire further research in the fields of nonequilibrium statistical mechanics and nonequilibrium molecular dynamics.

The influence mechanism of planned behavior and self-consciousness on learners’ willingness to use language learning Apps: Validation based on structural equation modeling

The continuous development of digital technology facilitates the informatization of foreign language learning, making it possible to create a deeply integrated mobile learning environment which is conducive to enhancing learning efficiency. To investigate learners’ willingness to use mobile language leaning applications (Apps), this research is carried out under an extended theoretical framework of Technology Acceptance Model (TAM) and Theory of Planned Behavior (TAM) by incorporating self-consciousness. On the basis of the survey data of 728 college students, structural equation modeling is constructed and empirically tested with AMOS 23.0. Results show that the structural equation modeling based on the extended TAM-TPB framework is suitable for analyzing the influencing mechanism of learners’ willingness to use language learning Apps. College students’ willingness to use language learning Apps is directly affected by behavioral attitudes, subjective norms, and perceived behavior control. Perceived ease of use has a significant direct impact on perceived usefulness. However, perceived ease of use and perceived usefulness have different mediating effects on learners’ willingness to use language learning Apps through behavioral attitudes, subjective norms, and perceived behavior control. Based on the findings, this paper suggests that when developing language learning Apps, emphasis should be laid on the positive feedback of learners’ self-consciousness and user enjoyment, as well as the construction of a curriculum system centered on core competencies so as to enhance learners’ willingness to use language learning Apps, thereby promoting language learning efficiency.