The sensitive aspects of modelling polymer-ceramic composite solid-state electrolytes using molecular dynamics simulations.

Solid-state composite electrolytes have arisen as one of the most promising materials classes for next-generation Li-ion battery technology. These composites mix ceramic and solid-polymer ion conductors with the aim of combining the advantages of each material. The ion-transport mechanisms within such materials, however, remain elusive. This knowledge gap can to a large part be attributed to difficulties in studying processes at the ceramic-polymer interface, which are expected to play a major role in the overall ion transport through the electrolyte. Computational efforts have the potential of providing significant insight into these processes. One of the main challenges to overcome is then to understand how a sufficiently robust model can be constructed in order to provide reliable results. To this end, a series of molecular dynamics simulations are here carried out with a variation of certain structural (surface termination and polymer length) and pair potential (van der Waals parameters and partial charges) models of the Li7La3Zr2O12 (LLZO) poly(ethylene oxide) (PEO) system, in order to test how sensitive the outcome is to each variation. The study shows that the static and dynamic properties of Li-ion are significantly affected by van der Waals parameters as well as the surface terminations, while the thickness of the interfacial region - where the structure-dynamic properties are different as compared to the bulk-like regime - is the same irrespective of the simulation setup.

Theoretical investigation of solvent and oxidation/deprotonation effects on the electronic structure of a mononuclear Ru-aqua-polypyridine complex in aqueous solution.

Mononuclear polypyridine ruthenium (Ru) complexes can catalyze various reactions, including water splitting, and can also serve as photosensitizers in solar cells. Despite recent progress in their synthesis, accurately modeling their physicochemical properties, particularly in solution, remains challenging. Herein, we conduct a theoretical investigation of the structural and electronic properties of a mononuclear Ru-aqua polypyridine complex in aqueous solution, considering five of its possible oxidation/protonation states species: [RuII(H2O)(py)(bpy)2]2+, [RuII(OH)(py)(bpy)2]+, [RuIII(H2O)(py)(bpy)2]3+, [RuIII(OH)(py)(bpy)2]2+ and [RuIV(O)(py)(bpy)2]2+, where py = pyridine and bpy = 2,2'-bipyridine. At first, we investigate the impact of proton-coupled and non-coupled electron transfer reactions on the geometry and electronic structure of the complexes in vacuum and in solution, using an implicit solvent model. Then, using a sequential multiscale approach that combines quantum mechanics and molecular mechanics (S-QM/MM), we examine the explicit solvent effects on the electronic excitations of the complexes, and compare them with the experimental results. The complexes were synthesized, and their absorption spectra measured in aqueous solution. To accurately describe the QM interactions between the metal center and the aqueous ligand in the MM simulations, we developed new force field parameters for the Ru atom. We analyze the solvent structure around the complexes and account for its explicit influence on the polarization and electronic excitations of the complexes. Notably, accounting for the explicit solvent polarization effects of the first solvation shells is essential to correctly describe the energy of the electronic transitions, and the explicit treatment of the hydrogen bonds at the QM level in the excitation calculations improves the accuracy of the description of the metal-to-ligand charge-transfer bands. Transition density matrix analysis is used to characterize all electronic transitions in the visible and ultraviolet ranges according to their charge-transfer (CT) character. This study elucidates the electronic structure of those ruthenium polypyridyl complexes in aqueous solution and underscores the importance of precisely describing solvent effects, which can be achieved employing the S-QM/MM method.

Unveiling the impact of exchange-correlation functionals on the description of key electronic properties of non-fullerene acceptors in organic photovoltaics.

Non-fullerene electron acceptors have emerged as promising alternatives to traditional electron-acceptors in the active layers of organic photovoltaics. This is due to their tunable energy levels, optical response in the visible light spectrum, high electron mobility, and photochemical stability. In this study, the electronic properties of two representative non-fullerene acceptors, ITIC and Y5, have been calculated within the framework of density functional theory using a range of hybrid and non-hybrid density functionals. Screened range-separated hybrid (SRSH) approaches were also tested. The results are analyzed in light of the previously reported experimental outcomes. Specifically, we have calculated the oxidation and reduction potentials, fundamental and optical gaps, the highest occupied molecular orbital and lowest unoccupied molecular orbital energies, and exciton binding energies. Additionally, we have investigated the effects of the medium dielectric constant on these properties employing a universal implicit solvent model. It was found that hybrid functionals generally perform poorly in predicting oxidation potentials, while non-hybrid functionals tend to overestimate reduction potentials. The inclusion of a large Hartree-Fock contribution to the global or long range was identified as the source of inaccuracy for many hybrid functionals in predicting both redox potentials and the fundamental and optical gaps. Corroborating with the available literature, ∼50% of all tested functionals predicted very small exciton binding energies, within the range of ±0.1 eV, that become even smaller by increasing the dielectric constant of the material. Finally, the OHSE2PBE and tHCTHhyb functionals and the optimal tuning SRSH approach emerged as the best-performing methods, with good accuracy in the description of the electronic properties of interest.

Dietary high-protein distiller's dried grains with solubles can fully replace soybean meal in diets for meat quails without affecting growth performance.

1. The purpose of this study was to determine the metabolisable energy of high-protein distiller's dried grains with solubles (HP-DDGS) for meat quail (Coturnix coturnix coturnix; Experiment I) and evaluate the effects of dietary levels of HP-DDGS on animal performance, carcase characteristics, meat quality, and organ weights (Experiment II).2. In Experiment 1, 96 meat quail were distributed in a completely randomised design with two treatments (reference or test diet) and six replicates of eight birds. The experimental period consisted of 5 d adaptation, followed by 5 d total excreta collection. The experimental diets consisted of a reference (control) and a test diet formulated with 800 g/kg reference diet and 200 g/kg HP-DDGS.3. In Experiment 2, 612 meat quail were distributed in a completely randomised design fed one of six dietary levels of HP-DDGS (0, 85, 170, 255, 340, or 425 g/kg) as a replacement for soybean meal. At 42 d of age, birds were slaughtered and evaluated for carcase yield, organ weights, and meat quality.4. Apparent metabolisable energy values corrected for nitrogen retention of HP-DDGS were 12.5 and 12.3 MJ/kg for males and females, respectively.5. In the starter phase (1-21 d of age), increasing dietary HP-DDGS levels had a quadratic effect on body weight (BW) (P = 0.020) and body weight gain (BWG) (P = 0.019). The maximum BW and BWG values were estimated to be achieved with 296.0 and 296.2 g/kg dietary HP-DDGS, respectively. Overall (1-42 d of age), increasing dietary HP-DDGS levels in replacement of soybean meal did not affect animal performance, carcase yield, meat quality or organ weight in meat quail.6. It was concluded that dietary HP-DDGS can fully replace soybean meal in meat quail diets without affecting growth performance, carcase yield, meat quality or organ weight.

On the Conformation of Dimeric Acceptors and Their Polymer Solar Cells with Efficiency over 18 .

The determination of molecular conformations of oligomeric acceptors (OAs) and their impact on molecular packing are crucial for understanding the photovoltaic performance of their resulting polymer solar cells (PSCs) but have not been well studied yet. Herein, we synthesized two dimeric acceptor materials, DIBP3F-Se and DIBP3F-S, which bridged two segments of Y6-derivatives by selenophene and thiophene, respectively. Theoretical simulation and experimental 1D and 2D NMR spectroscopic studies prove that both dimers exhibit O-shaped conformations other than S- or U-shaped counter-ones. Notably, this O-shaped conformation is likely governed by a distinctive "conformational lock" mechanism, arising from the intensified intramolecular π-π interactions among their two terminal groups within the dimers. PSCs based on DIBP3F-Se deliver a maximum efficiency of 18.09 %, outperforming DIBP3F-S-based cells (16.11 %) and ranking among the highest efficiencies for OA-based PSCs. This work demonstrates a facile method to obtain OA conformations and highlights the potential of dimeric acceptors for high-performance PSCs.

Formation of topological defects in nematic shells with a dumbbell-like shape.

The present study investigates dumbbell-shaped nematic liquid crystal shells. Using molecular dynamics (MD) simulations, we consider the effects of an external electric field on nematic ordering by computing the average molecular alignment's time evolution and equilibrium configuration. We show that the number and location of topological defects are strongly affected by the external field, with the orientational ordering's equilibrium configuration depending on field direction about the shell's long axis. For a transverse external field, it is verified that the defect rearrangement presents a non-linear dynamics, with a field independent characteristic time scale delimiting the short and long time regimes. Effects associated with varying the shell's Gaussian curvature are also analyzed.

Unraveling the acid-base characterization and solvent effects on the structural and electronic properties of a bis-bidentate bridging ligand.

Understanding the interactions and the solvent effects on the distribution of several species in equilibrium and how it can influence the 1H-NMR properties, spectroscopy (UV-vis absorption), and the acid-base equilibria can be especially challenging. This is the case of a bis-bidentate bridging ligand bis(2-pyridyl)-benzo-bis(imidazole), where the two pyridyl and four imidazolyl nitrogen atoms can be protonated in different ways, depending on the solvent, generating many isomeric/tautomeric species. Herein, we report a combined theoretical-experimental approach based on a sequential quantum mechanics/molecular mechanics procedure that was successfully applied to describe in detail the acid-base characterization and its effects on the electronic properties of such a molecule in solution. The calculated free-energies allowed the identification of the main species present in solution as a function of the solvent polarity, and its effects on the magnetic shielding of protons (1H-NMR chemical shifts), the UV-vis absorption spectra, and the acid-base equilibrium constants (pKas) in aqueous solution. Three acid-base equilibrium constants were experimentally/theoretically determined (pKa1 = 1.3/1.2, pKa2 = 2.1/2.2 and pKa5 = 10.1/11.3) involving mono-deprotonated and mono-protonated cis and trans species. Interestingly, other processes with pKa3 = 3.7 and pKa4 = 6.0 were also experimentally determined and assigned to the protonation and deprotonation of dimeric species. The dimerization of the most stable neutral species was investigated by Monte Carlo simulations and its electronic effects were considered for the elucidation of the UV-vis absorption bands, revealing transitions mainly with the charge-transfer characteristic and involving both the monomeric species and the dimeric species. The good matching of the theoretical and experimental results provides an atomistic insight into the solvent effects on the electronic properties of this bis-bidentate bridging ligand.

Understanding the lithiation limits of high-capacity organic battery anodes by atomic charge derivative analysis.

The superlithiation of organic anodes is a promising approach for developing the next generation of sustainable Li-ion batteries with high capacity. However, the lack of fundamental understanding hinders its faster development. Here, a systematic study of the lithiation processes in a set of dicarboxylate-based materials is carried out within the density functional theory formalism. It is demonstrated that a combined analysis of the Li insertion reaction thermodynamics and the conjugated-moiety charge derivative enables establishing the experimentally observed maximum storage, thus allowing an assessment of the structure-function relationships also.

Small Organic Molecule Based on Benzothiadiazole for Electrocatalytic Hydrogen Production.

A small organic molecule 2,1,3-benzothiadiazole-4, 7-dicarbonitrile (BTDN) is assessed for electrocatalytic hydrogen evolution on glassy carbon electrode and shows a hydrogen production Faradaic efficiency of 82% in the presence of salicylic acid. The key catalytic intermediates of reduced species BTDN-• and protonated intermediates are characterized or hypothesized by using various spectroscopic methods and density functional theory (DFT)-based calculations. With the experimental and theoretical results, a catalytic mechanism of BTDN for electrocatalytic H2 evolution is proposed.

Understanding carbon dioxide capture on metal-organic frameworks from first-principles theory: The case of MIL-53(X), with X = Fe3+, Al3+, and Cu2.

Metal-organic frameworks (MOFs) constitute a class of three-dimensional porous materials that have shown applicability for carbon dioxide capture at low pressures, which is particularly advantageous in dealing with the well-known environmental problem related to the carbon dioxide emissions into the atmosphere. In this work, the effect of changing the metallic center in the inorganic counterpart of MIL-53 (X), where X = Fe3+, Al3+, and Cu2+, has been assessed over the ability of the porous material to adsorb carbon dioxide by means of first-principles theory. In general, the non-spin polarized computational method has led to adsorption energies in fair agreement with the experimental outcomes, where the carbon dioxide stabilizes at the pore center through long-range interactions via oxygen atoms with the axial hydroxyl groups in the inorganic counterpart. However, spin-polarization effects in connection with the Hubbard corrections, on Fe 3d and Cu 3d states, were needed to properly describe the metal orbital occupancy in the open-shell systems (Fe- and Cu-based MOFs). This methodology gave rise to a coherent high-spin configuration, with five unpaired electrons, for Fe atoms leading to a better agreement with the experimental results. Within the GGA+U level of theory, the binding energy for the Cu-based MOF is found to be Eb = -35.85 kJ/mol, which is within the desirable values for gas capture applications. Moreover, it has been verified that the adsorption energetics is dominated by the gas-framework and internal weak interactions.

First genotyping of Trypanosoma cruzi from naturally infected Triatoma juazeirensis, Triatoma melanica and Triatoma sherlocki from Bahia State, Brazil.

Many previous studies have shown a great phylogenetic and biological variability of Trypanosoma cruzi using different molecular and biochemical methods. Populations of T. cruzi were initially clustered into two main lineages called TcI and TcII by the size of the mini-exon PCR product. In the present study, 33 isolates derived from three triatomine taxa, which belong to the Triatoma brasiliensis species complex (Triatoma juazeirensis, Triatoma melanica and Triatoma sherlocki); collected in three distinct areas of Bahia state were characterized by PCR. The isolates were identified by the size of the mini-exon gene, 18S rRNA and 24Sα rRNA amplicons. T. cruzi isolates obtained in sylvatic and intradomiciliar ecotopes, derived from T. juazeirensis and T. melanica, were identified as TcI while the parasites originated from T. sherlocki were characterized as TcI and TcII genotypes, respectively. Those species are present in sylvatic ecotopes but are able to infest intradomiciliar areas. Therefore, it would be important to maintain studies in those localities of Bahia and further investigate the possibilities of Chagas disease transmission. Human disease may occur by any T. cruzi genotype and not only by TcII as it is the case in Amazonia.

Brachio-cervical inflammatory myopathy associated with systemic sclerosis. Case series and review of literature.

This study was aimed at describing a case series of brachio-cervical inflammatory myopathy (BCIM) associated with systemic sclerosis (SSc), due to its rarity and limited coverage in published data. Another aim was to provide a literature review. We reported four cases of BCIM-SSc from our tertiary center. In addition, we researched the literature and found six articles featuring 17 patients who fit this phenotype. We pooled all cases and reported their features. Most patients were female and had limited SSc, and the median time of BCIM presentation was three years after SSc diagnosis. Asymmetric muscle involvement, scapular winging, dropped head, axial weakness, camptocormia, dysphagia, and dermatomyositis stigmas were common features. All patients had esophageal involvement. Most had positive antinuclear antibody results, a scleroderma pattern in their capillaroscopy images, elevated serum creatine phosphokinase, myopathic electrophysiology, and muscle involvement in magnetic resonance imaging. Muscle histopathological findings varied widely, but in general all showed the presence of lymphoid infiltrates, muscle atrophy, increased MHC-I expression, MAC deposits, vasculopathy, and muscle fiber necrosis. The response to immunosuppressive therapy was highly irregular. BCIM-SSc is a rare disorder that shares many similar phenotypes among the described cases, but has a highly heterogeneous response to treatment. At present, more data on the physiopathology, clinical features, and treatment is still needed.

Monensin associated or not with virginiamycin or functional oil for feedlot beef cattle.

The objective of this study was to evaluate diets containing monensin (MON) associated or not with virginiamycin (VM) or functional oil based on cashew nut shell and castor beans (FOcc) for beef cattle in feedlots on nutritional (intake and digestibility) and productive parameters. A total of 1410 non-castrated Nellore cattle were selected, with an average age of 18 months and with an initial mean body weight (BW) of 305 ± 41.52 kg. The diet showed a roughage to concentrate ratio of 23:77, with the supply of corn silage as a source of roughage. The following additive inclusions in the diet were evaluated: (1) MON: 27 mg MON/kg dry matter (DM); (2) MON + VM: 22 mg MON/kg DM + 19 mg VM/kg DM; and (3) MON + FOcc: 22 mg MON/kg DM + 500 mg FOcc/kg DM. Statistical analyses were obtained through a linear model using initial BW and days of feedlot as covariables and comparisons between treatments using mutually orthogonal linear contrasts with a 5% significance level. The association or not of MON with VM or FOcc does not affect any of the nutritional and productive parameters evaluated. Animals that receive diets with MON + VM have higher average daily gain and feed efficiency (FE) than those that receive MON + FOcc without showing differences in nutritional parameters. The supply of MON associated with VM or FOcc does not increase intake and productive performance and, consequently, efficiency of feedlot beef cattle. However, in the case of use associated with MON, the VM provides greater performance than FOcc without changing food intake.

Is there a reliable association between patient-reported limb claudication and vascular imaging methods in Takayasu arteritis?

Vessel imaging in Takayasu arteritis (TAK) is often performed in clinical practice following laboratory test abnormalities or clinical symptoms, such as limb claudication. Conversely, the association between limb claudication and vessel imaging manifestations has not been assessed. This observational, cross-sectional study analyzed 139 adult TAK patients from 2000 to 2018. Their arterial vessel imaging information (especially significant stenosis and occlusion data) was registered and crosschecked with clinical and laboratory data. When vessel imaging was performed, the median age and disease duration of the patients were 38 (27.3-47.0) and 5.0 (1.0-12.0) years, respectively. There was no association between arterial abnormalities and demographic data, constitutional symptoms or laboratory parameters. Limb claudication was reported in 42 patients (30.2%): 17.3% reported it in the upper left limb (ULL), 12.2% reported it in the upper right limb (URL), 12.9% reported it in the lower left limb (LLL), and 12.2% reported it in the lower right limb (LRL). When crossmatched with imaging, both ULL and URL were associated with left vertebral artery stenosis/occlusion, and URL was associated with right iliac artery stenosis/occlusion, but no other association was found. In contrast, both LLL and LRL claudication were associated with infrarenal aortic, left iliac and right iliac artery stenosis/ occlusion (p<0.05). Moreover, the ULL and URL claudication symptoms were significantly associated with each other (p<0.001). Upper limb claudication was associated only with left vertebral artery stenosis/occlusion, whereas the subclavian arteries were not, suggesting that the symptom might not be fully explained by limb ischemia. In contrast, lower limb claudication was associated especially with infrarenal aortic and/or iliac arteries stenosis/occlusion.

Spectroscopic Fingerprints of Intermolecular H-Bonding Interactions in Carbon Nitride Model Compounds.

The effect of intermolecular H-bonding interactions on the local electronic structure of N-containing functional groups (amino group and pyridine-like N) that are characteristic of polymeric carbon nitride materials p-CN(H), a new class of metal-free organophotocatalysts, was investigated. Specifically, the melamine molecule, a building block of p-CN(H), was characterized by X-ray photoelectron (XPS) and near edge X-ray absorption fine structure (NEXAFS) spectroscopy. The molecule was studied as a noninteracting system in the gas phase and in the solid state within a H-bonded network. With the support of DFT simulations of the spectra, it was found that the H-bonds mainly affect the N 1s level of the amino group, leaving the N 1s level of the pyridine-like N mostly unperturbed. This is responsible for a reduction of the chemical shift between the two XPS N 1s levels relative to free melamine. Consequently, N K-edge NEXAFS resonances involving the amino N 1s level also shift to lower photon energies. Moreover, the solid-state absorption spectra showed significant modification/quenching of resonances related to transitions from the amino N 1s level to σ* orbitals involving the NH2 termini.

Hydrogen Bond Dynamics of Cellulose through Inelastic Neutron Scattering Spectroscopy.

This work explores the dynamics of hydrogen bond networks in cellulose through inelastic neutron scattering (INS) and periodic CASTEP calculations. Estimated spectra were based on the crystal structure of cellulose Iα and Iß and replicate the INS spectrum of cellulose samples with remarkable similarity, allowing a reliable assignment of INS bands to vibrational modes of cellulose. Comparison of cellulose samples from varied sources, from bacterial to kraft pulp, allows the identification of characteristic INS bands, arising from C2-OH torsional motions, which easily identify which allomorph-Iα or Iß-is prevalent. A high crystallinity index is revealed by the presence of well-defined INS bands associated with highly cooperative CH bending modes along the chain. Hydrating kraft cellulose samples clearly affects those INS bands related with the hydroxymethyl group, identified as the preferred binding site for water molecules. At high humidity content level, a significant proportion of the water molecules is aggregated in clusters within the amorphous cellulose domains. The formation of ice microcrystals leads to a partial disruption of the hydrogen-bond network, as can be concluded from the observed red-shift of the torsional OH vibrational modes. The full assignment and interpretation of cellulose's INS spectra herein provided is a sound basis for future use of INS spectroscopy in the characterization of functionalized cellulose fibers and composite materials.

Addition of a Second Metal (Co) to Molybdenum Carbide: Effect of the Doping Route.

Molybdenum carbide is an interesting and versatile material, which has important applications in the metal matrix industry as a reinforcement material, as well as in the catalytic field. Though many papers suggest different methodologies for adding cobalt to the carbide structure aiming either to increase catalytic activity or enhancing mechanical proprieties such as ductility, etc. no straightforward evaluation is available. In the present paper two doping methodologies were studied: via solid state mixture of powders and via wet impregnation. Ammonium molybdate [(NH4)2MoO4] and cobalt nitrate [Co(NO3)2·6H2O] were used as starting materials and the doping process was carried out before carburization reaction. Those materials were characterized by FT-IR, SEM, XRF and XRD. The carbo-reduction products' were evaluated on XRD and XRF basis. Doped precursors' evaluation showed that the wet impregnated doped materials presented smaller particle sizes, were more homogeneous and retained more cobalt than the solid state doped ones. However, final products' assessment indicated that the solid state methodology was able to retain a greater dopant percentage according to XRF evaluation, and XRD data indicated a more intrinsic addition of the dopant to the carbide structure. In addition, no significant changes on particle size could be attributed to any of the methodologies, both producing Mo2C of approximately 30 nm.

Ascaris suum infection modulates inflammation: Implication of CD4+ CD25high Foxp3+ T cells and IL-10.

Helminth infections have the ability to modulate host's immune response through mechanisms that allow the chronic persistence of the worms in the host. Here, we investigated the mechanisms involved on the suppressive effect of Ascaris suum infection using a murine experimental model of LPS-induced inflammation. We found that infection with A. suum markedly inhibited leucocyte influx induced by LPS into air pouches, suppressed secretion of pro-inflammatory cytokines (IL-1ß, TNF-α and IL-6) and induced high levels of IL-10 and TGF-ß. Augmented frequency of CD4+ CD25high Foxp3+ T cells was observed in the mesenteric lymph nodes of infected mice. Adoptive transfer of purified CD4+ CD25+ T cells to recipient uninfected mice demonstrated that these cells were able to induce a suppressive effect in the LPS-induced inflammation in air pouch model. In addition, adoptive transfer of CD4+ CD25+ T cells derived from IL-10 knockout mice suggests that this suppressive effect of A. suum infection involves IL-10 cytokine. In conclusion, our results demonstrated that A. suum experimental infection was capable of suppressing LPS-induced inflammation by mechanisms, which seem to be dependent on responses of CD4+ CD25+ T cells and secretion of IL-10 cytokine.