Adsorption of multiple NO molecules on Au10- and Au9Zn- planar clusters. A comparative DFT study.

The doping of atomic clusters with transition-metal atoms modifies to a lesser or greater extent the catalytic properties of the pure forms. Here we study by means of density functional theory (DFT) the adsorption of up to six NO molecules on Au10- and Au9Zn- clusters, both with well-tested D3h planar geometry, to learn how precise modifications of the atomic and electronic environment, namely one atom and a valence electron, affect the bonding of multiple NO molecules to anionic gold clusters. First, we confirm that these clusters have D3h symmetry as determined by L. S. Wang and coworkers using photoelectron spectroscopy experiments [Kulichenko et al., J. Phys. Chem. A, 2021, 125, 4606]. Second, we verify that Au10(NO)n- with n ≤ 6 does not form adsorbed (NO)2 dimers, as realized by the experiments of Ma and coworkers [Ma et al., Phys. Chem. Chem. Phys., 2020, 22, 25227] using a mini flow-tube reactor at 150 K. Third, we discover that the ground state of the doped Au9Zn(NO)6- compound forms a (NO)2cis-dimer bridging two non-corner Au atoms of the Au9Zn(NO)4- compound. The discussion of adsorption energies, spin multiplicities, bond lengths, charge trends, vibrational strength frequencies of adsorbed NO's, and projected density of states (PDOS), brings additional testable differences between Au10(NO)n- and Au9Zn(NO)n- compounds (n ≤ 6).

Interactions of nitric oxide molecules with pure and oxidized silver clusters Agn ±/AgnO± (n=11-13): A computational study.

In this work, we have studied, within density functional theory, the interaction of NO with pure and oxidized silver clusters, both anionic and cationic, composed from 11 to 13 Ag atoms. In that size interval, shell closing effects are not expected, and structural and electronic odd-even effects will determine the strength of interaction. First, we obtained that species Agn ± and AgnO± with odd number of electrons (n = 12) adsorb NO with higher energy than their neighbors (n = 11 and 13). This result is in agreement with the facts observed in recent mass spectroscopy measurements, which were performed, however, at finite temperature. The adsorption energy is about twice for oxidized clusters compared to pure ones and higher for anions than for cations. Second, the adsorption of another NO molecule on AgnNO± forms Agn(NO)2 ±, with the dimer (NO)2 in cis configuration, and binding the two N atoms with two neighbor Ag atoms. The n = 12 species show the higher adsorption energy again. Third, in the absence of reaction barriers, all complexes Agn(NO)2 ± dissociate spontaneously into AgnO± and N2O, except the n = 12 anion. The maximum high barrier along the dissociation path of Ag13(NO)2 - is about 0.7 eV. Further analysis of projected density of states for Ag11-13(NO)x ± (x = 0, 1, 2) molecules shows that bonding between NO and Ag clusters mainly occurs in the energy range between -3.0 and 3.0 eV. The overlap between 4d of Ag and 2p of N and O is larger for Ag12(NO)2 ± than for neighbor sizes. For n = 12, the d bands are close to the (NO)2 2π orbital, leading to extra back-donation charge from the 4d of Ag to the closer 2π orbital of (NO)2.

Nanowire reconstruction under external magnetic fields.

We consider the different structures that a magnetic nanowire adsorbed on a surface may adopt under the influence of external magnetic or electric fields. First, we propose a theoretical framework based on an Ising-like extension of the 1D Frenkel-Kontorova model, which is analyzed in detail using the transfer matrix formalism, determining a rich phase diagram displaying structural reconstructions at finite fields and an antiferromagnetic-paramagnetic phase transition of second order. Our conclusions are validated using ab initio calculations with density functional theory, paving the way for the search of actual materials where this complex phenomenon can be observed in the laboratory.

Study of odd-even effects in physisorption and chemisorption of Ar, N2, O2 and NO on open shell Ag11-13+ clusters by means of self-consistent van der Waals density functional calculations.

We have studied the adsorption and coadsorption properties of one or more X = Ar, N2, O2, and NO adsorbates on cationic silver clusters Ag11-13+, whose sizes are in the open shell region of metal clusters, aiming to understand the observed odd-even effects in the abundance spectra of Ag11-13+·mX complexes. All calculations were performed self-consistently using a non-local van der Waals correlation functional, covering the different nature of the interactions between the silver substrate and the several adsorbates, which range from dispersion (London) forces for Ar, non covalent π-π interactions for N2, charge-transfer interactions for O2 and NO, and the covalent Ag-Ag bond in the nude silver cluster. Despite the wide interval of adsorption energies, spanning two orders of magnitude, we have been able to explain the following experimental facts. For X = Ar, N2, and O2 reactions with Ag11-13+, it was observed in the mass spectra an abundance peak at n = 12 [M. Schmidt, et al., ChemPhysChem, 2015, 16, 855]. In addition it was observed the competitive adsorption of two or more N2 molecules, and the cooperative effect of adsorbing N2 together with O2 molecules. For X = NO, an abundance peak at n = 12 has been also observed [J. Ma, et al., Phys. Chem. Chem. Phys., 2016, 18, 12819]. We find that the main factors determining these properties are the different core motifs of the cluster geometry (pentagonal bipiramid for Ag11+ and Ag13+, but triangular prism for Ag12+) and, on the other hand, the odd number of valence electrons for Ag12+, leading to a smaller HOMO-LUMO gap than those of its neighbours. Further details about the preferred adsorption sites, dipole moments, and dipole polarizabilities are also discussed.

Hydrogen Chemisorption on Singly Vanadium-Doped Aluminum Clusters.

The effect of vanadium doping on the hydrogen adsorption capacity of aluminum clusters (Aln+ , n=2-18) is studied experimentally by mass spectrometry and infrared multiple photon dissociation (IRMPD) spectroscopy. We find that vanadium doping enhances the reactivity of the clusters towards hydrogen, albeit in a size-dependent way. IRMPD spectra, which provide a fingerprint of the hydrogen binding geometry, show that H2 dissociates upon adsorption. Density functional theory (DFT) calculations for the smaller Aln V+ (n=2-8,10) clusters are in good agreement with the observed reactivity pattern and underline the importance of activation barriers in the chemisorption process. Orbital analysis shows that the activation barriers are due to an unfavorable overlap between cluster and hydrogen orbitals.

Heterodimerization of p45-p75 modulates p75 signaling: structural basis and mechanism of action.

The p75 neurotrophin receptor, a member of the tumor necrosis factor receptor superfamily, is required as a co-receptor for the Nogo receptor (NgR) to mediate the activity of myelin-associated inhibitors such as Nogo, MAG, and OMgp. p45/NRH2/PLAIDD is a p75 homologue and contains a death domain (DD). Here we report that p45 markedly interferes with the function of p75 as a co-receptor for NgR. P45 forms heterodimers with p75 and thereby blocks RhoA activation and inhibition of neurite outgrowth induced by myelin-associated inhibitors. p45 binds p75 through both its transmembrane (TM) domain and DD. To understand the underlying mechanisms, we have determined the three-dimensional NMR solution structure of the intracellular domain of p45 and characterized its interaction with p75. We have identified the residues involved in such interaction by NMR and co-immunoprecipitation. The DD of p45 binds the DD of p75 by electrostatic interactions. In addition, previous reports suggested that Cys257 in the p75 TM domain is required for signaling. We found that the interaction of the cysteine 58 of p45 with the cysteine 257 of p75 within the TM domain is necessary for p45-p75 heterodimerization. These results suggest a mechanism involving both the TM domain and the DD of p45 to regulate p75-mediated signaling.

Intrinsic fluid interfaces and nonlocality.

We present results of an extensive molecular dynamics simulation of the structure and fluctuations of a liquid-gas interface, close to its triple point, in a system with cutoff Lennard-Jones interactions. The equilibrium density profile, averaged and (shape dependent) constrained intrinsic density profiles together with the fluctuations of the interfacial shape are extracted using an intrinsic sampling method. The correlation between fluctuations in the interfacial shape and in the intrinsic density show that the latter is not due to rigid translations of some underlying profile, as is most commonly assumed. Instead, over the whole range of wavelengths from the system size down to the molecular diameter, we see wave-vector dependent behavior in good agreement with a nonlocal interfacial Hamiltonian theory specifying the shape dependence of the intrinsic profiles.

Evaluation of Nutritional Practices in the Critical Care patient (The ENPIC study): Does nutrition really affect ICU mortality?

BACKGROUND & AIMS: The importance of artificial nutritional therapy is underrecognized, typically being considered an adjunctive rather than a primary therapy. We aimed to evaluate the influence of nutritional therapy on mortality in critically ill patients. METHODS: This multicenter prospective observational study included adult patients needing artificial nutritional therapy for >48 h if they stayed in one of 38 participating intensive care units for ≥72 h between April and July 2018. Demographic data, comorbidities, diagnoses, nutritional status and therapy (type and details for ≤14 days), and outcomes were registered in a database. Confounders such as disease severity, patient type (e.g., medical, surgical or trauma), and type and duration of nutritional therapy were also included in a multivariate analysis, and hazard ratios (HRs) and 95% confidence intervals (95%CIs) were reported. RESULTS: We included 639 patients among whom 448 (70.1%) and 191 (29.9%) received enteral and parenteral nutrition, respectively. Mortality was 25.6%, with non-survivors having the following characteristics: older age; more comorbidities; higher Sequential Organ Failure Assessment (SOFA) scores (6.6 ± 3.3 vs 8.4 ± 3.7; P < 0.001); greater nutritional risk (Nutrition Risk in the Critically Ill [NUTRIC] score: 3.8 ± 2.1 vs 5.2 ± 1.7; P < 0.001); more vasopressor requirements (70.4% vs 83.5%; P=0.001); and more renal replacement therapy (12.2% vs 23.2%; P=0.001). Multivariate analysis showed that older age (HR: 1.023; 95% CI: 1.008-1.038; P=0.003), higher SOFA score (HR: 1.096; 95% CI: 1.036-1.160; P=0.001), higher NUTRIC score (HR: 1.136; 95% CI: 1.025-1.259; P=0.015), requiring parenteral nutrition after starting enteral nutrition (HR: 2.368; 95% CI: 1.168-4.798; P=0.017), and a higher mean Kcal/Kg/day intake (HR: 1.057; 95% CI: 1.015-1.101; P=0.008) were associated with mortality. By contrast, a higher mean protein intake protected against mortality (HR: 0.507; 95% CI: 0.263-0.977; P=0.042). CONCLUSIONS: Old age, higher organ failure scores, and greater nutritional risk appear to be associated with higher mortality. Patients who need parenteral nutrition after starting enteral nutrition may represent a high-risk subgroup for mortality due to illness severity and problems receiving appropriate nutritional therapy. Mean calorie and protein delivery also appeared to influence outcomes. TRIAL REGISTRATION: ClinicaTrials.gov NCT: 03634943.

GGA versus van der Waals density functional results for mixed gold/mercury molecules and pure Au and Hg cluster properties.

Dispersion forces, which originate the van der Waals interaction, are indispensable to describe numerous systems and processes, including metallic clusters and surfaces. In this work is used an efficient numerical implementation in the context of density functional theory of a non-local correlation van der Waals density functional (vdW-DF) to self-consistently solve the structure and electronic properties of small molecules (ArAu, AuF, ArAuF, ArCuF, Au(2)Hg, Au(2)Hg(2)), as well as Au(2-15) and Hg(2-6) clusters. Three different flavours of that vdW-DF exchange-correlation (xc) functional are tested. The results for small molecules are compared with those from the generalized gradient approximation (GGA) of Perdew, Burke, and Ernzerhof (PBE) against experiments or highly accurate quantum chemical calculations. It is found that, on average, vdw-DF improves PBE binding energies and overestimates bond distances. Our vdW-DF calculations lead to planar structures as lowest energy isomers of Au(14) and Au(15) clusters. The calculated polarizability of Au(2-15) isomers dramatically decreases in passing from two-dimensional (2D) to three-dimensional (3D) equilibrium geometries. A combination of the density of states of two vdw-DF planar isomers of the Au(12)(-) anion is proposed to explain the photoelectron spectroscopy experiments. Contrary to PBE results, the vdW-DF calculations predict that the O(h) isomer of Hg(6) is more stable than the C(2v) one.

High-Performance Room Temperature Lithium-Ion Battery Solid Polymer Electrolytes Based on Poly(vinylidene fluoride-co-hexafluoropropylene) Combining Ionic Liquid and Zeolite.

The demand for more efficient energy storage devices has led to the exponential growth of lithium-ion batteries. To overcome the limitations of these systems in terms of safety and to reduce environmental impact, solid-state technology emerges as a suitable approach. This work reports on a three-component solid polymer electrolyte system based on poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), the ionic liquid 1-butyl-3-methylimidazolium thiocyanate ([BMIM][SCN]), and clinoptilolite zeolite (CPT). The influences of the preparation method and of the dopants on the electrolyte stability, ionic conductivity, and battery performance were studied. The developed electrolytes show an improved room temperature ionic conductivity (1.9 × 10-4 S cm-1), thermal stability (up to 300 °C), and mechanical stability. The corresponding batteries exhibit an outstanding room temperature performance of 160.3 mAh g-1 at a C/15-rate, with a capacity retention of 76% after 50 cycles. These results represent a step forward in a promising technology aiming the widespread implementation of solid-state batteries.

Theoretical study of oxygen adsorption on pure Au(n+1)+ and doped MAu(n)+ cationic gold clusters for M = Ti, Fe and n = 3-7.

A comparative study of the adsorption of an O2 molecule on pure Au(n+1)+ and doped MAu(n)+ cationic gold clusters for n = 3-7 and M = Ti, Fe is presented. The simultaneous adsorption of two oxygen atoms also was studied. This work was performed by means of first principles calculations based on norm-conserving pseudo-potentials and numerical basis sets. For pure Au4 +, Au6+, and Au7+ clusters, the O2 molecule is adsorbed preferably on top of low coordinated Au atoms, with an adsorption energy smaller than 0.5 eV. Instead, for Au5+ and Au8+, bridge adsorption sites are preferred with adsorption energies of 0.56 and 0.69 eV, respectively. The ground-state geometry of Au(n)+ is almost unperturbed after O2 adsorption. The electronic charge flows towards O2 when the molecule is adsorbed in bridge positions and towards the gold cluster when O2 is adsorbed on top of Au atoms, and both the adsorption energy and the O-O bond length of adsorbed oxygen increase when the amount of electronic charge on O2 increases. On the other hand, we studied the adsorption of an O2 molecule on doped MAu(n)+ clusters, leading to the formation of (MAu(n)O2+) ad complexes with different equilibrium configurations. The highest adsorption energy was obtained when both atoms of O2 bind on top of the M impurity, and it is larger for Ti doped clusters than for Fe doped clusters, showing an odd-even effect trend with size n, which is opposite for Ti as compared to Fe complexes. For those adsorption configurations of (MAu(n)O2+) ad involving only Au sites, the adsorption energy is similar to or smaller than that for similar configurations of Au(n)+1O2 + complexes. However, the highest adsorption energy of (MAu(n)O2+) ad is higher than that for (Au(n)+1O2+) ad by a factor of approximately 4.0 (1.2) for M = Ti (M = Fe). The trends with size n are rationalized in terms of O-O and O-M bond distances, as well as charge transfer between oxygen and cluster substrates. The spin multiplicity of those (MAu(n)O2+) ad complexes with the highest O2 adsorption energy is a maximum (minimum) for M = Fe (Ti), corresponding to parallel (anti-parallel) spin coupling of MAu(n)+ clusters and O2 molecules. Finally, we obtained the minimum energy equilibrium structure of complexes (Au(n)O2+) dis and (MAu(n)O2+) dis containing two separated O atoms bonded at different sites of Au(n)+ and MAu(n)+ clusters, respectively. For (MAu(n)O2 (+)) dis, the equilibrium configuration with the highest adsorption energy is stable against separation in MAu(n)+ and O2 fragments, respectively. Instead, for (Au(n)O2+) dis, only the complex n = 6 is stable against separation in Au(n)+ and O2 fragments. The maximum separation energy of (MAu(n)O2+) dis is higher than the O2 adsorption energy of (MAu(n)O2+) ad complexes by factors of approximately 1.6 (2.5), 1.6 (1.7), 1.5 (2.4), 1.5 (1.3), and 1.6 (1.8) for M = Ti (Fe) complexes in the range n = 3-7, respectively.

[Osgood-Schlatter disease in adolescent athlete. Case report]. / Enfermedad de Osgood-Schlatter en un adolescente deportista. Caso clínico.

Knee pain is one of the most frequent musculoskeletal symptoms in young physically active males. Common entities of clinical diagnosis as osteochondritis/apophysitis and others that need complementary studies should be considered in the differential diagnosis. We present the case of a 12-year-old male athlete with continuous pain in his right knee that intensifies with physical activity and with direct pressure. Diagnosis of Osgood-Schlatter disease is made by exploratory data, pain-to-finger palpation on the anterior tibial tuberosity, and is confirmed by radiology. This entity is described as well as the main pathologies derived from overuse to make differential diagnosis and to stress preventive measures regarding a correct orientation in the sport activity.

El dolor de rodilla es uno de los síntomas musculoesqueléticos más frecuentes en jóvenes físicamente activos y aparece, sobre todo, en adolescentes varones. Dentro del diagnóstico diferencial, hay que considerar entidades habituales de diagnóstico clínico, como la osteocondrosis apofisaria, y también otras en las que se precisan estudios complementarios. Se presenta el caso de un varón deportista de 12 años con dolor continuo en la rodilla derecha que se intensificaba con la actividad física y la presión directa. Se hizo el diagnóstico de enfermedad de Osgood-Schlatter mediante los datos exploratorios, reproducción del dolor ante la palpación a punta de dedo sobre la tuberosidad tibial anterior, y se confirmó mediante radiología. Se describe esta entidad y otras derivadas de la sobreutilización en la actividad física con las que hacer diagnóstico diferencial; se insiste en las medidas preventivas en cuanto a una correcta orientación en la actividad deportiva.

Theoretical study of CO adsorption on gold/alumina substrates.

Aiming to understand the role of the substrate in the adsorption of carbon monoxide on gold clusters supported on metal-oxides, we have started a study of that process on two different alumina substrates: an amorphous-like fully relaxed stoichiometric (Al2O3)20 cluster and the Al terminated (0001) surface of alpha-(Al2O3) crystal. In this paper, we present first principles calculations for the adsorption of one Au atom on both alumina substrate and the adsorption of Au8 on (Al2O3)20. Then, we study the CO adsorption on the minimum energy structure of these three different gold/alumina systems. A single Au adsorbs preferably on top of an Al atom with low coordination, the binding energy being higher in the case of Au/(Al2O3)20. CO absorbs preferably on top of the Au atom, but in the case of Au/(Al2O3)20, Au forms a bridge with the Al and O substrate atoms after CO adsorption. We find other stable sites for CO adsorption on the cluster but not on the surface. This result suggests that the Au activity toward CO may be larger for the amorphous cluster than for the crystal surface substrate. For the most stable Au8/(Al2O3)20 configuration, two Au atoms bind to Al and a O atoms respectively and CO adsorbs on top of the Au which binds to the Al atom. We find other CO adsorption sites on supported Au8 which are not stable for the free Au8 cluster.

Implicit Prosody and Cue-based Retrieval: L1 and L2 Agreement and Comprehension during Reading.

This project focuses on structural and prosodic effects during reading, examining their influence on agreement processing and comprehension in native English (L1) and Spanish-English bilingual (L2) speakers. We consolidate research from several distinct areas of inquiry-cognitive processing, reading fluency, and L1/L2 processing-in order to support the integration of prosody with a cue-based retrieval mechanism for subject-verb agreement. To explore this proposal, the experimental design manipulated text presentation to influence implicit prosody, using sentences designed to induce subject-verb agreement attraction errors. Materials included simple and complex relative clauses with head nouns and verbs that were either matched or mismatched for number. Participants read items in one of three presentation formats (whole sentence, word-by-word, or phrase-by-phrase), rated each item for grammaticality, and responded to a comprehension probe. Results indicated that while overall, message comprehension was prioritized over subject-verb agreement computation, presentation format differentially affected both measures in the L1 and L2 groups. For the L1 participants, facilitating the projection of phrasal prosody onto text (phrase-by-phrase presentation) enhanced performance in agreement processing, while disrupting prosodic projection via word-by-word presentation decreased comprehension accuracy. For the L2 participants, however, phrase-by-phrase presentation was not significantly beneficial for agreement processing, and additionally resulted in lower comprehension accuracy. These differences point to a significant role of prosodic phrasing during agreement processing in both L1 and L2 speakers, additionally suggesting that it may contribute to a cue-based retrieval agreement model, either acting as a cue directly, or otherwise scaffolding the retrieval process. The discussion and results presented provide support both for a cue-based retrieval mechanism in agreement, and the function of prosody within such a mechanism, adding further insight into the interaction of retrieval processes, cognitive task load, and the role of implicit prosody.

Secondary coenzyme Q10 deficiencies in oxidative phosphorylation (OXPHOS) and non-OXPHOS disorders.

We evaluated the coenzyme Q10 (CoQ) levels in patients who were diagnosed with mitochondrial oxidative phosphorylation (OXPHOS) and non-OXPHOS disorders (n=72). Data from the 72 cases in this study revealed that 44.4% of patients showed low CoQ concentrations in either their skeletal muscle or skin fibroblasts. Our findings suggest that secondary CoQ deficiency is a common finding in OXPHOS and non-OXPHOS disorders. We hypothesize that cases of CoQ deficiency associated with OXPHOS defects could be an adaptive mechanism to maintain a balanced OXPHOS, although the mechanisms explaining these deficiencies and the pathophysiological role of secondary CoQ deficiency deserves further investigation.

Mesoscopic Hamiltonian for the fluctuations of adsorbed Lennard-Jones liquid films.

We use Monte Carlo simulations of a Lennard-Jones fluid adsorbed on a short-range planar wall substrate to study the fluctuations in the thickness of the wetting layer, and we get a quantitative and consistent characterization of their mesoscopic Hamiltonian, H[ξ]. We have observed important finite-size effects, which were hampering the analysis of previous results obtained with smaller systems. The results presented here support an appealing simple functional form for H[ξ], close but not exactly equal to the theoretical nonlocal proposal made on the basis a generic density-functional analysis by Parry and coworkers. We have analyzed systems under different wetting conditions, as a proof of principle for a method that provides a quantitative bridge between the molecular interactions and the phenomenology of wetting films at mesoscopic scales.

Brain expressed and X-linked (Bex) proteins are intrinsically disordered proteins (IDPs) and form new signaling hubs.

Intrinsically disordered proteins (IDPs) are abundant in complex organisms. Due to their promiscuous nature and their ability to adopt several conformations IDPs constitute important points of network regulation. The family of Brain Expressed and X-linked (Bex) proteins consists of 5 members in humans (Bex1-5). Recent reports have implicated Bex proteins in transcriptional regulation and signaling pathways involved in neurodegeneration, cancer, cell cycle and tumor growth. However, structural and biophysical data for this protein family is almost non-existent. We used bioinformatics analyses to show that Bex proteins contain long regions of intrinsic disorder which are conserved across all members. Moreover, we confirmed the intrinsic disorder by circular dichroism spectroscopy of Bex1 after expression and purification in E. coli. These observations strongly suggest that Bex proteins constitute a new group of IDPs. Based on these findings, together with the demonstrated promiscuity of Bex proteins and their involvement in different signaling pathways, we propose that Bex family members play important roles in the formation of protein network hubs.

Interaction of HLA-DR with actin microfilaments.

Capping of HLA-DR on the surface of a human lymphoblastoid cell line (RAJI) and a transfectant human fibroblast cell line (M1DR1) was studied by confocal microscopy. Capping was induced at 22 degrees C after treating cells with an HLA-DR specific monoclonal antibody, L243, followed by a secondary antibody conjugated with FITC. Cytoskeletal actin filaments (F-actin) accumulated under the caps were detected by rhodamine-phalloidin fluorescence. Two processes appear to take place: in the round lymphoblastoid cells, actin, initially distributed uniformly at the cell periphery, redistributes and becomes concentrated underneath HLA-DR patches or caps. In the non-round, substrate-attached fibroblasts, actin was organized in tightly packed filaments along the plasma membrane. It was observed that crosslinked HLA-DR receptors were associated with these filaments and were dragged toward the perinuclear area of the cells, where they coalesce to form a cap. The cytoskeleton-disrupting drugs that inhibit actin polymerisation were used to investigate the mechanism of capping of HLA-DR molecules. Sodium nitroprusside, a nitric oxide releasing agent, cytochalasin D both inhibited the percentage of capping in a dose-dependent manner. These data suggest that on antigen presenting cells, such as B cells and fibroblasts, actin microfilaments acts as a regulator of the movement and capping of HLA-DR receptors.

Effect of dispersion forces on the capillary-wave fluctuations of liquid surfaces.

We present molecular dynamics evidence for the nonanalytic effects of the long-range dispersion forces on the capillary waves fluctuations of a Lennard-Jones liquid surface. The results of the intrinsic sampling method, for the analysis of the instantaneous interfacial shape, are obtained in large systems for several cut-off distances of the potential tail, and they show good agreement with the theoretical prediction by Napiórkowski and Dietrich, based on a density functional analysis. The enhancement of the capillary waves is quantified to be within 1% for a simple liquid near its triple point.