Stable and Fast Ion Transport Electrolyte Interfaces Modified with Novel Fluorine- and Nitrogen-Containing Solvents for Ni-Rich Cathode Materials.

Ternary nickel-rich layered oxide LiNi0.8Co0.1Mn0.1O2 (NCM811) is recognized as a cathode material with a promising future, attributed to its high energy density. However, the pulverization of cathode particles, structural collapse, and electrolyte decomposition are closely associated with the fragile cathode-electrolyte interphases (CEI), which seriously affect the electrochemical performances of ternary high-nickel materials. In this paper, fluorine- and nitrogen-containing methyl-2-nitro-4-(trifluoromethyl)benzoate (MNTB) was selected, which was synergistically regulated with fluoroethylene carbonate (FEC) to generate a robust CEI film. The preferential decomposition of MNTB/FEC results in the formation of an inorganic-rich (Li3N, LiF, and Li2O) CEI film with uniformly dense and stable characteristics, which is conducive to the migration of Li+ and the stability of the NCM811 structure and enhances the cycling stability of the battery system. Simultaneously, MNTB effectively suppresses the adverse reaction associated with increased polarization caused by higher interface impedance due to conventional single FEC additives, further improving the rate capability of the battery. Moreover, MNTB/FEC can effectively eliminate HF, preventing its corrosion on the NCM811 cathode. Under the synergistic effect of MNTB/FEC, after 300 discharge cycles at a high cutoff voltage of 4.3 V and a current density of 1 C (2 mA cm-2), the discharge capacity of the NCM811||Li battery was 150.12 mA h g-1 with a capacity retention of 81.10%, while it was only 32.8% for the standard electrolyte (STD). The discharged capacity of the MNTB/FEC-containing battery was about 115.43 mA h g-1 at the high rate of 7 C, which was considerably higher than that of the STD (93.34 mA h g-1). In this study, the designed MNTB as a novel solvent synergistically regulated with FEC will contribute to the enhanced stability of NCM811 materials at high cutoff voltages and at the same time provide an effective modified strategy to enhance the stability of commercial electrodes.

Highly Stable Silicon Anode Enabled by a Water-Soluble Tannic Acid Functionalized Dual-Network Binder.

Silicon (Si), a high-capacity electrode material, is crucial for achieving high-energy-density lithium-ion batteries. However, Si suffers from poor cycling stability due to its significant volume changes during operation. In this work, a tannic acid functionalized aqueous dual-network binder with an intramolecular tannic acid functionalized network has been synthesized, which is composed of covalent-cross-linked polyamide and ionic-cross-linked alginate (Alg(Ni)-PAM-TA), and employed as an advanced binder for stabilizing Si anodes. The resultant Alg(Ni)-PAM-TA binder, incorporating diverse functional groups including amide, carboxylic acid, and dynamic hydrogen bonds, can easily interact with both Si nanoparticles and the Cu foil, thereby facilitating the formation of a highly resilient network characterized by exceptional adhesion strength. Moreover, molecular dynamics (MD) simulations indicate that the Alg(Ni)-PAM-TA network shows an increased intramolecular hydrogen bond number with increasing concentration of TA and a decreased intramolecular hydrogen bond between PAM and Alg as a result of the aggregation behavior of tannic acids themselves. Consequently, the binder significantly enhances the Si electrode's integrity throughout repeated charge/discharge cycles. At a current density of 0.84 A g-1, the Si electrode retains a capacity of 1863.4 mAh g-1 after 200 cycles. This aqueous binder functionalized with the intramolecular network via the incorporation of TA molecules holds great promise for the development of high-energy-density lithium-ion batteries.

Bioaccumulation and thyroid endcrione disruption of 2-ethylhexyl diphenyl phosphate at environmental concentration in zebrafish larvae.

2-ethylhexyl diphenyl phosphate (EHDPP) strongly binds to transthyretin (TTR) and affects the expression of genes involved in the thyroid hormone (TH) pathway in vitro. However, it is still unknown whether EHDPP induces endocrine disruption of THs in vivo. In this study, zebrafish (Danio rerio) embryos (< 2 h post-fertilization (hpf)) were exposed to environmentally relevant concentrations of EHDPP (0, 0.1, 1, 10, and 100 µg·L-1) for 120 h. EHDPP was detected in 120 hpf larvae at concentrations of 0.06, 0.15, 3.71, and 59.77 µg·g-1 dry weight in the 0.1, 1, 10, and 100 µg·L-1 exposure groups, respectively. Zebrafish development and growth were inhibited by EHDPP, as indicated by the increased malformation rate, decreased survival rate, and shortened body length. Exposure to lower concentrations of EHDPP (0.1 and 1 µg·L-1) significantly decreased the whole-body thyroxine (T4) and triiodothyronine (T3) levels and altered the expressions of genes and proteins involved in the hypothalamic-pituitary-thyroid axis. Downregulation of genes related to TH synthesis (nis and tg) and TH metabolism (dio1 and dio2) may be partially responsible for the decreased T4 and T3 levels, respectively. EHDPP exposure also significantly increased the transcription of genes involved in thyroid development (nkx2.1 and pax8), which may stimulate the growth of thyroid primordium to compensate for hypothyroidism. Moreover, EHDPP exposure significantly decreased the gene and protein expression of the transport protein transthyretin (TTR) in a concentration-dependent manner, suggesting a significant inhibitory effect of EHDPP on TTR. Molecular docking results showed that EHDPP and T4 partly share the same mode of action of binding to the TTR protein, which might result in decreased T4 transport due to the binding of EHDPP to the TTR protein. Taken together, our findings indicate that EHDPP can cause TH disruption in zebrafish and help elucidate the mechanisms underlying EHDPP toxicity.

A Biodegradable Polyester-Based Polymer Electrolyte for Solid-State Lithium Batteries.

The low ionic conductivity, narrow electrochemical window, poor interfacial stability with lithium metal, and non-degradability of raw materials are the main problems of solid polymer electrolytes, restricting the development of lithium solid-state batteries. In this paper, a biodegradable poly (2,3-butanediol/1,3-propanediol/succinic acid/sebacic acid/itaconic acid) ester was designed and used as a substrate to prepare biodegradable polyester solid polymer electrolytes for solid-state lithium batteries using a simple solution-casting method. A large number of ester-based polar groups in the amorphous polymer become a high-speed channel for carrying lithium ions as a weak coordination site. The biodegradable polyester solid polymer electrolyte exhibits a wide electrochemical window of 5.08 V (vs. Li/Li+), high ionic conductivity of 1.03 mS cm-1 (25 °C), and a large Li+ transference number of 0.56. The electrolyte exhibits good interfacial stability with lithium, with stable Li plating/stripping behavior at room temperature over 2100 h. This design strategy for biodegradable polyester solid polymer electrolytes offers new possibilities for the development of matrix materials for environmentally friendly lithium metal solid-state batteries.

Mussel-Inspired Polydopamine Composite Mesoporous Bioactive Glass Nanoparticles: An Exploration of Potential Metal-Ion Loading Platform and In Vitro Bioactivity.

Exploring new approaches to realize the possibility of incorporating biologically active elements into mesoporous silicate bioactive glass nanoparticles (MBG NPs) and guaranteeing their meso- structural integrity and dimensional stability has become an attractive and interesting challenge in biomaterials science. We present a postgrafting strategy for introducing different metal elements into MBG NPs. This strategy is mediated by polydopamine (PDA) coating, achieving uniform loading of copper or copper-cobalt on the particles efficiently and ensuring the stability of MBG NPs in terms of particle size, mesoporous structure, and chemical structure. However, the PDA coating reduced the ion-binding free energy of the MBG NPs for calcium and phosphate ions, resulting in the deposition of minimal CaP clusters on the PDA@MBG NP surface when immersed for 7 days in simulated body fluid, indicating the absence of hydroxyapatite mineralization.

Detection of Mild Cognitive Impairment from Language Markers with Crossmodal Augmentation.

Mild cognitive impairment is the prodromal stage of Alzheimer's disease. Its detection has been a critical task for establishing cohort studies and developing therapeutic interventions for Alzheimer's. Various types of markers have been developed for detection. For example, imaging markers from neuroimaging have shown great sensitivity, while its cost is still prohibitive for large-scale screening of early dementia. Recent advances from digital biomarkers, such as language markers, have provided an accessible and affordable alternative. While imaging markers give anatomical descriptions of the brain, language markers capture the behavior characteristics of early dementia subjects. Such differences suggest the benefits of auxiliary information from the imaging modality to improve the predictive power of unimodal predictive models based on language markers alone. However, one significant barrier to the joint analysis is that in typical cohorts, there are only very limited subjects that have both imaging and language modalities. To tackle this challenge, in this paper, we develop a novel crossmodal augmentation tool, which leverages auxiliary imaging information to improve the feature space of language markers so that a subject with only language markers can benefit from imaging information through the augmentation. Our experimental results show that the multi-modal predictive model trained with language markers and auxiliary imaging information significantly outperforms unimodal predictive models.

Molecular Dynamics Simulation of Biomimetic Biphasic Calcium Phosphate Nanoparticles.

Biphasic calcium phosphate (BCP) is used as a bone substitute and bone tissue repair material due to its better control over bioactivity and biodegradability. It is crucial to stabilize the implanted biomaterial while promoting bone ingrowth. However, a lack of standard experimental and theoretical protocols to characterize the physicochemical properties of BCP limits the optimization of its composition and properties. Computational simulations can help us better to learn BCP at a nanoscale level. Here, the Voronoi tessellation method was combined with simulated annealing molecular dynamics to construct BCP nanoparticle models of different sizes, which were used to understand the physicochemical properties of BCP (e.g., melting point, infrared spectrum, and mechanical properties). We observed a ∼20 to 30 Å layer of calcium-deficient hydroxyapatite at the HAP/ß-TCP interface due to particle migration, which may contribute to BCP stability. The BCP model may stimulate further research into BCP ceramics and multiphasic ceramics. Moreover, our study may facilitate the optimization of compositions of BCP-based biomaterials.

Molecular investigations of the prenucleation mechanism of bone-like apatite assisted by type I collagen nanofibrils: insights into intrafibrillar mineralization.

Bone is a typical inorganic-organic composite material with a multilevel hierarchical organization. In the lowest level of bone tissue, inorganic minerals, which are mainly composed of hydroxyapatite, are mineralized within the type I collagen fibril scaffold. Understanding the crystal prenucleation mechanism and growth of the inorganic phase is particularly important in the design and development of materials with biomimetic nanostructures. In this study, we built an all-atom human type I collagen fibrillar model with a 67 nm overlap/gap D-periodicity. Arginine residues were shown to serve as the dominant cross-linker to stabilize the fibril scaffold. Subsequently, the prenucleation mechanism of collagen intrafibrillar mineralization was investigated using a molecular dynamics approach. Considering the physiological pH of the human body (i.e., ∼7.4), HPO42- was initially used to simulate the protonation state of the phosphate ions. Due to the spatially constrained effects resulting from the overlap/gap structure of the collagen fibrils, calcium phosphate clusters formed mainly inside the hole zone but with different spatial distributions along the long axis direction; this indicated that the nucleation of calcium phosphate may be highly site-selective. Furthermore, the model containing both HPO42- and PO43- in the solution phase formed significantly larger clusters without any change in the nucleation sites. This phenomenon suggests that the existence of PO43- is beneficial for the mineralization process, and so the conversion of HPO42- to PO43- was considered a critical step during mineralization. Finally, we summarize the nucleation mechanism for collagen intrafibrillar mineralization, which could contribute to the fabrication of mineralized collagen biomimetic materials.

Molecular dynamic simulation of prenucleation of apatite at a type I collagen template: ion association and mineralization control.

Biomineralization is a vital physiological process in living organisms, hence elucidating its mechanism is crucial in the optimization of controllable biomaterial preparation with hydroxyapatite and collagen, which could provide information for the design of innovative biomaterials. However, the mechanisms by which minerals and collagen interact in various ionic environments are unclear. Here, we applied molecular dynamics and free energy simulations to clarify type I collagen-mediated HAP prenucleation and simulated the physiological environment using different phosphate and carbonate protonation states. Calcium phosphate mineral formation on the type I collagen surface drastically differed among various H2PO4-, HPO42-, PO43-, CO32-, and HCO3- compositions. Our simulations indicated that the presence of HPO42- in the solution phase is critical to regulate the apatite nucleation, whereas the presence of H2PO4- may be inhibitory. The inclusion of CO32- in the solution might promote calcium phosphate cluster formation. In contrast, apatite cluster size may be regulated by changing the anion concentration ratios, including PO43-/HPO42- and PO43-/CO32-. Our free energy simulations attributed these phenomena to relative differences in binding thermostability and ion association kinetics. Our simulations provide a theoretical approach toward the effective control of collagen mineralization and the preparation of novel biomaterials.

Molecular Dynamics Exploration of the Growth Mechanism of Hydroxyapatite Nanoparticles Regulated by Glutamic Acid.

Morphological control can enhance the performance of materials like hydroxyapatite (HAP), a well-known bioceramic with various morphologies, including spheres, rods, whiskers, needles, and plates. To obtain certain HAP morphologies, the crystal growth mechanisms at different planes should be investigated. Here, molecular dynamics was employed to understand the mechanism of HAP nanoparticle growth regulated by glutamic acid (Glu). Long-time dynamics simulations and free energy calculations were performed to explore the effect of Glu on calcium and phosphate ion precipitation on the HAP (100) and (001) faces. Without Glu, PO43- prefers binding to the HAP (100) surface, whereas with Glu, the (001) surface is preferred. This could partially explain why HAP changes from needle-like to plate-like with Glu addition in experiments. Our theoretical results indicate that Glu inhibits calcium and phosphate ion deposition on the crystal surfaces by occupying the calcium sites on the outermost layers. In addition, Glu has a strong concentration gradient effect on HAP deposition. At Glu concentrations of >80 mM, ion deposition was inhibited more on the (100) than on the (001) surface. Our results agree with experimental observations and afford insights into complicated HAP crystal growth mechanisms with foreign additives, which will aid in HAP synthesis with morphological control.

Preparation and Laser Marking Properties of Poly(propylene)/Molybdenum Sulfide Composite Materials.

In this study, using molybdenum sulfide (MoS2) as laser-sensitive particles and poly(propylene) (PP) as the matrix resin, laser-markable PP/MoS2 composite materials with different MoS2 contents ranging from 0.005 to 0.2% were prepared by melt-blending. A comprehensive analysis of the laser marking performance of PP/MoS2 composites was carried out by controlling the content of laser additives, laser current intensity, and the scanning speed of laser marking. The color difference test shows that the best laser marking performance of the composite can be obtained at the MoS2 content of 0.02 wt %. The surface morphology of the PP/MoS2 composite material was observed after laser marking using a metallographic microscope, an optical microscope, and a scanning electron microscope (SEM). During the laser marking process, the laser energy was absorbed and converted into heat energy to cause high-temperature melting, pyrolysis, and carbonization of PP on the surface of the PP/MoS2 composite material. The black marking from carbonized materials was formed in contrast to the white matrix. Using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and Raman spectroscopy, the composite materials before and after laser marking were tested and characterized. The PP/MoS2 composite material was pyrolyzed to form amorphous carbonized materials. The effect of the laser-sensitive MoS2 additive on the mechanical properties of composite materials was investigated. The results show that the PP/MoS2 composite has the best laser marking property when the MoS2 loading content is 0.02 wt %, the laser marking current intensity is 11 A, and the laser marking speed is 800 mm/s, leading to a clear and high-contrast marking pattern.

Construction of Self-Assembled Polyelectrolyte/Cationic Microgel Multilayers and Their Interaction with Anionic Dyes Using Quartz Crystal Microbalance and Atomic Force Microscopy.

This study aimed to reveal the interaction between self-assembled multilayers and dye molecules in the environment, which is closely related to the multilayers' stable performance and service life. In this work, the pH-responsive poly (N-isopropylacrylamide-co-2-(dimethylamino) ethyl methacrylate) microgels were prepared by free-radical copolymerization and self-assembled with sodium alginate (SA) into multilayers by the layer-by-layer deposition method. Quartz crystal microbalance (QCM) and atomic force microscopy (AFM) results confirmed the construction of multilayers and the absorbed mass, resulting in a decrease in the frequency shift of the QCM sensor and the deposition of microgel particles on its surface. The interaction between the self-assembled SA/microgel multilayers and anionic dyes in the aqueous solution was further investigated by QCM, and it was found that the electrostatic attraction between dyes and microgels deposited on the QCM sensor surface was much larger than that of the microgels with SA in multilayers, leading to the release of the microgels from the self-assembled structure and a mass loss ratio of 27.6%. AFM observation of the multilayer morphology exposed to dyes showed that 29% of the microgels was peeled off, and the corresponding microgel imprints were generated on the surface. In contrast, the shape and size of the remaining self-assembled microgel particles did not change.

SACT: A New Model of Covert Communication Based on SDN.

Anonymous tracking technology of network watermarking is limited by the deployment of tracking devices in traditional network structure, resulting in poor scalability and reusability. Software Defined Network (SDN) boasts more freedom thanks to its separation of the control plane from the data plane. In this paper, a new anonymous communication tracking model SDN-based Anonymous Communication Tracking (SACT) is proposed, which introduces network watermarking into SDN and combines IP time hidden channel and symbol expansion technology. In addition, we introduce a hopping protection mechanism to improve the anti detection ability of the watermark as well. The experimental results show that in a variety of simulated network environments, SACT achieves excellent detection rate and bit error rate, thus it is sufficient to determine the communication relationship between the two parties. Meanwhile, SACT solves the deployment problem of anonymous tracking and improves the availability and scalability of covert communication.

Molecular docking and molecular dynamics simulation studies on the adsorption/desorption behavior of bone morphogenetic protein-7 on the ß-tricalcium phosphate surface.

The adsorption/desorption behavior, and conformational and orientational changes of proteins on the surface of biomaterials are significant parameters for understanding how biomaterials perform their biological functions. In this study, for the first time, the interactions between BMP-7 and ß-TCP (001) surface models with different ion-rich terminations (Ca-rich and P-rich) were investigated by molecular dynamics simulation (MD) and steered molecular dynamics simulation (SMD). The results indicated that BMP-7 preferentially interacts with both Ca-rich and P-rich ß-TCP (001) surfaces at its wrist epitope residues with certain conformational changes, which led to more exposure of BMP-7 knuckle epitope residues to the environment and facilitation for binding to the type II receptor. Compared to the P-rich surface, it is speculated that the Ca-rich surface was more conducive to BMP-7 signal transduction since the upright orientation of the protein adsorption would lead to smaller hindrance for receptor binding. This study provided more atomistic and molecular information for better understanding the process of Ca-P surfaces affecting BMP-7 biological properties and further interpreted the osteoinductive mechanism from the perspective of growth factor adsorption. Moreover, the docking screening method adopted in this study is of guiding significance to the design and development of bioactive materials.

Effect of Hydroxyapatite Surface on BMP-2 Biological Properties by Docking and Molecular Simulation Approaches.

The interactions between osteogenic proteins and the biomaterial surface are crucial to the application of biomaterials, in which the conformational or orientational change of the adsorbed protein on the solid surfaces is one of the most important interactions other than the protein adsorption. Although some progress has been made in the mechanism of protein adsorption on the surface of hydroxyapatite (HAP) in recent years, there is still insufficient atomistic/molecular information about the conformation and orientation of proteins upon adsorbing on solid surfaces. In this study, different orientations and conformations of bone morphological protein-2 (BMP-2) adsorbed on the surface of HAP were calculated through the protein-solid surface docking approach; the relationship between optimal adsorption and biological activity of BMP-2 was investigated by applying a combination of molecular dynamic simulation (MD) and steered molecular dynamic simulation (SMD). Two optimal adsorption conformers were screened out according to the docking results on the basis of orientations of BMP-2 with different epitopes. Subsequent MD and SMD results showed that the knuckle epitope of BMP-2 was easier to adsorb on the surface of HAP(100) than the wrist epitope accompanying certain conformational changes. Such an absorption mode led to the wrist epitope of BMP-2 being exposed to the environment and then being identified/interacted with type I receptors on the stem cell membrane, which further induces the differentiation of stem cells into osteoblasts. Current simulation provided a theoretical high-throughput screening method for the protein-biomaterial adsorption states. It can be extended to more research on different protein adsorptions on the surface of different materials. The simulation results provided more information at the molecular and atomic levels to further interpret the mechanism of osteoinductivity from the perspective of growth factor adsorption. Meanwhile, we believe that it should be a meaningful attempt to screen biomaterial key factors by the high-throughput method, which might become a promising way to develop or optimize new biomaterials.

Theoretical study on the metabolic mechanisms of levmepromazine by cytochrome P450.

Levomepromazine, an "older" typical neuroleptic, is widely applied in psychiatry for the treatment of schizophrenia. The biotransformation of Levomepromazine remains elusive up to now, but found to result in the formation of different derivatives that may contribute to the therapeutic and/or side-effects of the parent drug. The present work aims to resolve the metabolic details of Levomepromazine catalyzed by cytochrome P450, an important heme-containing enzyme superfamily, based on DFT calculation. Two main metabolic pathways have been addressed, S-oxidation and N-demethylation. The mechanistic conclusions have revealed a stepwise transfer of two electrons mechanism in S-oxidation reaction. N-demethylation is a two-step reaction, including the rate-determining N-methyl hydroxylation which proceeds via the single electron transfer (SET) mechanism and the subsequent C-N bond fission through a water-assisted enzymatic proton-transfer process. N-demethylation is more feasible than S-oxidation due to its lower activation energy and N-desmethyllevomepromazine therefore is the most plausible metabolite of Levomepromazine. Each metabolic pathway proceeds in a spin-selective manner (SSM) mechanism, predominately via the LS state of Cpd I. Our observations are in good accordance with the experimental results, which can provide some general implications for the metabolic mechanism of Levomepromazine-like drugs. Graphical abstract The metabolic mechanisms of levmepromazine by cytochrome P450.

Theoretical study on the N-demethylation mechanism of theobromine catalyzed by P450 isoenzyme 1A2.

Theobromine, a widely consumed pharmacological active substance, can cause undesirable muscle stiffness, nausea and anorexia in high doses ingestion. The main N-demethylation metabolic mechanism of theobromine catalyzed by P450 isoenzyme 1A2 (CYP1A2) has been explored in this work using the unrestricted hybrid density functional method UB3LYP in conjunction with the LACVP(Fe)/6-31G (H, C, N, O, S, Cl) basis set. Single-point calculations including empirical dispersion corrections were carried out at the higher 6-311++G** basis set. Two N-demethylation pathways were characterized, i.e., 3-N and 7-N demethylations, which involve the initial N-methyl hydroxylation to form carbinolamines and the subsequent carbinolamines decomposition to yield monomethylxanthines and formaldehydes. Our results have shown that the rate-limiting N-methyl hydroxylation occurs via a hydrogen atom transfer (HAT) mechanism, which proceeds in a spin-selective mechanism (SSM) in the gas phase. The carbinolamines generated are prone to decomposition via the contiguous heteroatom-assisted proton-transfer. Strikingly, 3-N demethylation is more favorable than 7-N demethylation due to its lower free energy barrier and 7-methylxanthine therefore is the optimum product reported for the demethylation of theobromine catalyzed by CYP1A2, which are in good agreement with the experimental observation. This work has first revealed the detail N-demethylation mechanisms of theobromine at the theoretical level. It can offer more significant information for the metabolism of purine alkaloid.