Binding Force Research Articles

Surface different charge ligands for modulating selenium nanoparticles formation and activating the interaction with proteins for effective anti-Herpes simplex virus l infection.

Selenium-based nanoparticles (Se NPs) exhibit antiviral activity by directly modulating immune function. Despite recent promising developments in utilizing Se NPs against viral infections, the impact of surface ligand charge on the conformation and interaction with viral proteins, as well as the effectiveness of Se NPs in anti-Herpes simplex virus 1 (HSV-1) infection remains unexplored. In this study, three types of selenium nanoparticles (CTAB-Se, PVP-Se, SDS-Se) with distinct surface charges were synthesized by modifying the surface ligands. We found that apart from differences in surface charge, the size, morphology, and crystal structure of the three types of Se NPs were similar. Notably, although the lipophilicity and cellular uptake of SDS-Se with a negative charge were lower compared to positively charged CTAB-Se and neutrally charged PVP-Se, SDS-Se exhibited the strongest protein binding force during interaction with HSV-1. Consequently, SDS-Se demonstrated the most potent anti-HSV-1 activity and safeguarded normal cells from damage. The mechanistic investigation further revealed that SDS-Se NPs effectively inhibited the proliferation and assembly of HSV-1 by powerfully suppressing the key genes and proteins of HSV-1 at various stages of viral development. Hence, this study highlights the significant role of surface ligand engineering in the antiviral activity of Se NPs, presenting a viable approach for synthesizing Se NPs with tailored antiviral properties by modulating surface charge. This method holds promise for advancing research on the antiviral capabilities of Se NPs.

Regulation of Microlocalization of Antioxidants by Surfactant Micelles in Oil-in-Water Emulsions.

The mass transport effect of aqueous micelles on antioxidants and oxidation products in emulsions may alter the rate, degree, and pathway of lipid oxidation. In this study, the dynamic mass transport of oxidation products and endogenous tocopherol during storage at different micelle concentrations was monitored by UV-vis spectrophotometry and high-performance liquid chromatography. Furthermore, the microlocalization of tocopherol in micelles was investigated using 1H nuclear magnetic resonance and nuclear Overhauser effect spectroscopy, fluorescence measurements, and molecular dynamics simulation. It was demonstrated that high-concentration micelles enhanced the emulsion stability by promoting the mass transport of hydroperoxides and endogenous antioxidants. The enhancement of micelles was a superposition effect of concentration, interaction sites, and binding force between tocopherols and Tween 20 molecules. Tween 20 concentration-induced favorable changes of microlocalization of tocopherol and dynamic mass transport demonstrated a new integrated perspective to control lipid oxidation.

Advanced N-doping nickel-cobalt phosphides for boosting hydrogen evolution in acid and alkali media

In this article, the hydrogen evolution performance in 0.5 M H2SO4 and 1.0 M KOH is improved by introducing N atoms into Ni2P/Co2P through high-temperature doping (N–Ni2P/Co2P). N–Ni2P/Co2P has a lower overpotential than Ni2P/Co2P, which can achieve cathodic current densities of 10 mA cm−2, 100 mA cm−2 at overpotentials of 48 mV, 228 mV in 1.0 M KOH and 63 mV, 211 mV in 0.5 M H2SO4. Density functional theory (DFT) results found that the introduction of N atoms changed the electronic structure of the catalyst. Due to the forward shift of d-band center, the binding force between the catalyst and H∗ is enhanced, providing favorable conditions for hydrogen evolution. Furthermore, the results of scaled-up tests show that 5 cm × 5 cm N–Ni2P/Co2P electrodes still exhibit superior performance, revealing a prospect of industrialization.

High stability of charged particle clusters in protoplanetary disks

Context. The initial particle growth in protoplanetary disks is limited by a bouncing barrier at submillimeter wavelengths. Bouncing leads to tribocharging and the electrostatic attraction of tribocharged aggregates may eventually draw them into large clusters. A charge- mediated growth phase allows for the formation of larger entities, namely, clusters of aggregates that are more prone to further particle concentrations, such as the streaming instability. Aims. We aim to quantify the strength of the electrostatic forces. Methods. In laboratory experiments, we used an acoustic trap to levitate small aggregates of tribocharged submm grains. These aggregates spin up within the trap until they lose grains. Thus, we used the centrifugal force as a measure of the local force. Results. Grains are regularly bound strongly to their neighbors. In comparison, the force at ejection can be stronger than the attractive scattering forces of the trap and can therefore be several orders of magnitude larger than expected. We note that these forces are long- ranging, compared to van der Waals forces. Thus, charged aggregates are much more stable than uncharged ones. Conclusions. Particle aggregates in disks might grow to centimeter clusters or larger as tribocharging increases the effective binding forces. This allows for hydrodynamic concentration and planetesimal formation to eventually take place throughout a wide part of the disk.

Synthesize and Applications of Green Custard Apples leaves biosorbents for adsorptions of Sulphates and Fluorides from water

Industrial and domestic waste water release sulphur and fluoride metals into the water, thereby polluting the environment and affecting the humans and animals health. There are various techniques are available for eliminating sulphates and fluorides found in the water. Among these techniques, biosorption is a simple, cost-effective and environmentally friendly approach for removing the sulphates and fluorides from water. Biosorption is a physiochemical process that physically produces in specific biomass, enabling it to passively concentrate and bind sulphates and fluorides to its cellular structure. The custard apple leaf biosorbents are among the most effective biosorbents for the removal of fluorides and sulphates from water. In the experimental work observed that the using of 5.6g dosage of custard apple leaf biosorbents, successfully removed the sulphates and fluorides from water and a stable condition was reached. The optimal sorption of sulphur and fluoride over custard apple leaves biosorbents was achieved at a basic pH of 4-8, a concentration of 4.3g, contact time of 60minutes, temperature of 25°C, and an agitation speed of 100rpm. The particles present in custard apple leaves biosorbents have a size of 3.26µm and crystallite size 3.02nm. The surface area, pore volume and pore size of 43.68m2/g, 0.428cm3/g, and 38.64Å respectively. The adsorption of sulphates and fluorides on regenerated custard apple leaves biosorbents remained consistent for up to three cycles, but then decreased by 82.36% in the fourth cycle. The regeneration of custard apple leaf biosorbents was also calibrated, and it was observed that the custard apple leaves do not exhibit any high concentrations of changes in their performances, even after being reused for the removals of sulphates and fluorides from water. The adsorption rate move to equilibrium was due to the accessibility of lower amount of existing opening sites on the custard apple leaves biosorbents surface and also due to the binding forces between the custard apple leaves biosorbents and fluorides and sulfates molecules in the aqueous solution.

Estro-Androgenic Disrupting Effects of Halogenated Disinfection Byproducts: A Comprehensive Evaluation and Comparison.

Drinking water halogenated disinfection byproducts (DBPs) have become an increasing health concern. However, the endocrine-disrupting effects of DBPs have not been well evaluated, and the limited available data have inhibited a comprehensive understanding of their health risks. In this study, a total of 43 DBPs were evaluated for their estro-androgenic effects using two types of human breast cancer cells. Among the tested DBPs, 16 exhibited estrogenic/antiestrogenic/androgenic/antiandrogenic effects, and the effects could be observed even at concentrations typically detected in drinking water. Iodinated and polyhalogenated DBPs generally showed higher effects than other species. For a broader comparison, DBP endocrine-disrupting effect data from this study and previous studies were summarized. It was found that the endocrine disruption efficacy of DBPs followed the rank order of iodinated > brominated > chlorinated species, and halophenolic DBPs were potential endocrine-disrupting compounds. Moreover, molecular docking results demonstrated that the binding of DBPs to estro-androgenic receptors was dominated by hydrophobic bonding, hydrogen bonding, halogen bonding, and van der Waals forces. The force strength and molecular volume were related to the magnitude of the estro-androgenic effects. Iodinated DBPs and polyhalogenated DBPs tended to have larger binding forces than other analogues and thus exhibited stronger effects.

Witnessing an extreme, highly efficient galaxy formation mode with resolved Lyman-α and Lyman-continuum emission

J1316+2614 at z = 3.613 is the UV-brightest (MUV = −24.7) and strongest Lyman continuum-emitting (fescLyC ≈ 90%) star-forming galaxy known; it also shows signatures of inflowing gas from its blue-dominated Lyα profile. We present high-resolution imaging with the Hubble Space Telescope (HST) and the Very Large Telescope (VLT) of the LyC, Lyα, rest-UV, and optical emission of J1316+2614. Detailed analysis of the LyC and UV light distributions reveals compact yet resolved profiles, with LyC and UV morphologies showing identical half-light radii of reff ≃ 220 pc. The continuum-subtracted Lyα emission, obtained with the HST ramp-filter FR551N, reveals an extended filamentary structure of ≃6.0 kpc oriented south to north with only residual flux within the stellar core, suggesting a Lyα ‘hole’. Our spectral energy distribution analysis shows that J1316+2614 is characterised by a young (5.7 ± 1.0 Myr), nearly un-obscured stellar population with a high star-formation rate (SFR = 898 ± 181 M⊙ yr−1) and a stellar mass of M⋆young = (4.8 ± 0.3) × 109 M⊙. Additionally, the spectral energy distribution analysis supports the absence of an underlying old stellar population (M⋆old ≤ 2.8 × 109 M⊙, 3σ). J1316+2614 presents remarkably high SFR and stellar mass surface densities of log(Σ SFR[M⊙ yr−1 kpc−2]) = 3.47 ± 0.11 and log(ΣM⋆[M⊙pc−2]) = 4.20 ± 0.06, respectively, which are among the highest observed in star-forming galaxies and are more typically observed in local young massive star clusters and globular clusters. Our findings indicate that J1316+2614 is a powerful, young, and compact starburst that is leaking a significant amount of LyC photons due to a lack of gas and dust within the starburst. We explored the conditions for gas expulsion using a simple energetic balance and find that, given the strong binding force in J1316+2614, a high star-formation efficiency (ϵSF ≥ 0.7) is necessary to explain the removal of gas and its exposed nature. Our results thus suggest a close link between high ϵSF and high fescLyC. This high efficiency can also naturally explain the remarkably high SFR, UV luminosity, and efficient mass growth of J1316+2614, which acquired at least 62% of its mass in the last 6 Myr. J1316+2614 may exemplify an intense, feedback-free starburst with a high ϵSF, similar to those proposed for UV-bright galaxies at high redshifts.

One-pot synthesis of transition metals-doped LiAl-LDHs to improve lithium adsorption performance and stability

Transition metal doping of Li/Al-LDHs can alter the interlayer spacing and surface charge of LDHs, thereby enhancing adsorption performance and stability. To investigate the rules and mechanisms governing the enhancement of stability and adsorption capacity of Li/Al-LDHs through transition metal element doping, several transition metal elements (Co, Zn, Mn, Zr, and Ni) were selected, and the five types of transition metal-doped Li/Al-LDHs and one undoped Li/Al-LDHs were synthesized by a one-pot method. Compared to the original Li/Al-LDHs, the Co-doped Li/Al-LDHs exhibited higher adsorption capacity, lower dissolution loss, and greater stability. Additionally, after Co doping, the lattice constant of Li/Al-LDHs decreases, effectively reducing the intercalation energy and increasing lithium diffusion efficiency. When used for lithium adsorption, Co-Li/Al-LDHs exhibited a Li+ capacity of 12.6 mg/g and reached saturation adsorption within 90 min. Notably, Co-Li/Al-LDHs achieved a high Li+ adsorption capacity (6.46 mg/g) in East Taigener salt-lake brine. After 10 cycles, the adsorption capacity did not show any significant change, and after 336 h adsorption-desorption cycles (200 rmp, oscillation), the total Al dissolution loss was only about 0.035 ‰, demonstrating that Co doping can enhance the interlayer binding force of Li/Al-LDHs, thereby reducing the decomposition of the layered structure in solution, lowering aluminum dissolution loss, and improving structural stability. The results show that doping with transition metals can reduce the Al dissolution rate of LDHs, and Co-Li/Al-LDHs can be used as an efficient adsorbent for lithium extraction from salt lake and have higher stability.

Size effect of ZIF-8 based nanocarrier pesticide delivery system on targeted release and insecticidal activity.

Traditional chemical pesticides are easily lost by surface runoff and only small quantities reach the target, thus causing serious environmental pollution. In this work, dinotefuran@zeolitic imidazolate framework-8@polydopamine@zein (DNF@ZIF-8@PDA@zein), was constructed to deliver DNF with pH and enzyme double response of release, thereby achieving targeted release and efficient long-term pest control. DNF@ZIF-8@PDA@zein was synthesized with three hydrated diameters (249.73 ± 9.99 nm, 142.94 ± 5.63 nm and 75.16 ± 4.66 nm, respectively). The release of DNF from DNF@ZIF-8@PDA@zein after 28 h was significantly higher at pH 5.0 (89.22 ± 7.18%) compared to that at pH 8 (81.8 ± 6.11%). Protease-assisted release of DNF was notably higher than that without protease (pH 5: 89.22 ± 5.55% versus 27.19 ± 3.22%; pH 8: 81.8 ± 6.11% versus 25.39 ± 3.87%). The stimuli-responsive release of DNF from DNF@ZIF-8@PDA@zein increased with decreased particle size due to increased pore size, reduced binding forces (i.e., weaker π-π stacking, hydrogen bonding, and Zn-N covalent bonding), and the shortening of diffusion path, leading to faster disintegration and drug release. Additionally, the anti-photolysis ability of DNF@ZIF-8@PDA@zein was 3.2 times that of pure DNF. The insecticidal activity improved with smaller nanoparticles due to higher drug release rate and greater inhibition of detoxification enzyme activity by more zinc ion (Zn2+) dissolution. The pH and enzyme dual-responsive release as well as insecticidal activity of DNF@ZIF-8@PDA@zein increase with decreased nanoparticle size, showing effective pest management in long-term and potential application prospects in sustainable agriculture. © 2024 Society of Chemical Industry.

Host-guest-induced electronic state triggers two-electron oxygen reduction electrocatalysis

Supramolecular polymers possess great potential in catalysis owing to their distinctive molecular recognition and dynamic crosslinking features. However, investigating supramolecular electrocatalysts with high efficiency in oxygen reduction reaction to hydrogen peroxide (ORHP) remains an unexplored frontier. Herein, we present organic polymers for ORHP by introducing cyclodextrin-containing noncovalent building blocks, affording these supramolecules with abundant dynamic bonds. The electronic states and reaction kinetics are further well-modulated via a host-guest strategy, resulting in appropriate regional electron binding force and controllable chemical activity. Notably, integrating supramolecular units into phenyl group-containing model covalent polymer achieves a production rate of 9.14 mol g−1cat h−1, with 98.01% Faraday efficiency, surpassing most reported metal-free electrocatalysts. Moreover, the dynamic bonds in supramolecular catalysts can effectively regulate the binding ability of oxygen intermediates, leading to high reactivity and selectivity for the 2e− pathway. Supported by theory calculation and in situ experiment, C atoms (site–1) adjacent to the –C = N (N) group are potential active sites. This work pioneers host-guest strategy and provides inspiring ideas for the ORHP process.

Preparation of Ovalbumin/Xanthan Gum/Chitosan Pickering Emulsion Oleogel Added with Amomum villosum Lour. Extract and Its Application in Cookies

In this study, a new oleogel system was constructed and used as a fat substitute in the processing of cookies. The preparation process of Amomum villosum Lour. extract (AVE) was optimized based on antioxidant activity and yield firstly. Then, the AVE, ovalbumin, chitosan, and xanthan gum were used as raw materials to prepare a composite Pickering emulsion oleogel. The results showed that when the concentration of AVE, chitosan, and XG were 0.1%, 2.5%, and 0.3%, respectively, a stable and uniformly distributed Pickering emulsion oleogel was formed. In this case, the particle size of the composite oleogel was relatively small; the absolute value of zeta potential was higher; the microstructure was more stable, with less aggregation and flocculation; and the thermal stability and freeze–thaw stability were excellent. In addition, the addition of AVE enhanced the gel properties of the oleogel and had good solid-like properties, and strengthened the binding force, as well as the oxidation stability, making the whole system more stable. In addition, the results of the application of the composite oleogel in the cookies showed that the AVE–ovalbumin/xanthan gum/chitosan Pickering emulsion oleogel had similar sensory and texture properties to the butter group. The addition of AVE can delay the crispness, cohesiveness, hardness, and the rate of malondialdehyde formation in cookies during storage. In conclusion, the AVE–ovalbumin/xanthan gum/chitosan Pickering emulsion oleogel had good physicochemical stability and showed great potential in replacing saturated fat (butter) in baking products (cookies).

In Situ Transformation of Hybrid Bismuth Halide into Rhombohedral Bismuth for Electrochemical CO2 Reduction to Formate

AbstractBi‐based electrocatalysts have attracted high attention due to their high selectivity for formate, low cost, and high biocompatibility. Surface modification with halides can adjust the surface charge distribution of metal catalysts, thereby regulating the binding force of the intermediate. Organic‐inorganic hybrid bismuth halides provide an alternative, especially low dimensional structures. Herein, zero‐dimensional hybrid bismuth halides containing Bi4I16 units (denoted as Bi4I16) was recommended as pre‐catalyst due to the Bi ⋅ ⋅ ⋅ Bi spacing in Bi4I16 is 4.760 Å, nearly equaling to the Bi ⋅ ⋅ ⋅ Bi spacing in rhombohedral Bi (4.750 Å). The equal spacing may be more beneficial for the electricity‐driven in situ conversion and rearrangement of Bi atoms in the catalytic process. As a contrast, zero‐dimensional bismuth halide containing Bi2I9 units (denoted as Bi2I9) with shorter Bi ⋅ ⋅ ⋅ Bi spacing (4.2415 Å) was prepared. The working electrode prepared by Bi4I16 ink was measured for CO2RR, and the partial formate current density can reach 8.2 mA cm−2 at −1.1 V vs RHE. The Bi4I16 catalyst delivers a maximum Faradaic Efficiency (FE, ~80 %) for formate at −0.86 V vs RHE and maintain a FE higher than 78.5 % after 16 h.

The Hell-or-High-Water Clause in Aircraft Leasing Contract: UNIDROIT Principles and the Indonesian Civil Code

This research analyses the hell-or-high-water clause in aircraft leasing contracts in the context of the principle of freedom of contract. Focusing on the review of the principle of freedom of contract based on UNIDROIT Principles of International Commercial Contract (UPICC) 2016 and Indonesian Civil Code, this research uses normative juridical method with analytical descriptive approach. The findings show that the hell-or-high-water clause has a high binding force, providing legal certainty, especially for the lessor. However, its application must be in line with the principle of freedom of contract regulated in UPICC 2016 and the Civil Code. The application of this clause is suggested to consider three limitations stipulated by the UPICC 2016: first, the principle of freedom of contract that allows businesses to choose partners and transaction terms; second, the exclusion of certain sectors in the public interest by the state; and third, mandatory rules that limit the content of the contract. Therefore, the hell-or-high-water clause should be applied with due regard to the implementation of the principle of freedom of contract as well as national law or the existence of compelling national regulations.

The Modern Institution of the Prosecutor's Refusal to File Charges against a Suspect: Crisis of Authenticity of the Russian Criminal Process

The paper examines the issues of effectiveness and viability of the modern Russian institution of prosecutor’s refusal to bring charges. The author substantiates the conclusion that it is formed to a greater extent in the spirit of Anglo-Saxon legal logic, while neither normative nor doctrinal correlation with the basic principles of domestic criminal proceedings has been implemented. The legal institution in question is a vivid example of conceptual, axiological legal contradictions in the Russian criminal process, which makes it difficult to clearly define its modern model and the vector of its further development. For methodological purposes, the modern Russian institution of the prosecutor’s refusal to charge was analyzed in relation to the trial with the participation of jurors. This made it possible to more fully identify the relevant shortcomings and identify areas for improvement. As a result, the following conclusions were substantiated: it would be advisable to deprive the prosecutor’s refusal to bring charges of binding force for the Russian court. At the same time, the adversarial foundation of the trial is not limited here in any way, since the prosecutor should have the opportunity to convey his position to the court following the results of the judicial investigation. In general, the proposed approach will act as a reliable guarantee of the rights of the victim, including access to justice, and serve to ensure the constitutional right of Russians to participate in the administration of justice, strengthen the independence and completeness of the judiciary. As a result, using the example of the institute under study, we can talk about the need to return to the authenticity of Russian criminal proceedings in the spirit of continental legal traditions.

Zwitterionic covalent organic nanosheets for selective analysis of domoic acid in marine environment

BackgroundDomoic acid (DA) is a neurotoxic compound causing amnesic shellfish poisoning, secreted by red algae and diatoms. As a glutamate analogue, DA accumulates in filter-feeding marine organisms, posing significant health risks to humans upon consumption. Detecting DA in marine environments remains challenging due to its low concentration and interference from complex matrices. Effective detection and removal require materials with high efficiency and selectivity, which traditional inorganic ionic materials lack due to their limited adsorption capacity and selectivity. Ionic covalent organic frameworks (iCOFs) expected to become highly efficient DA adsorbents due to tunable ionic sites. ResultsThus, a zwitterionic covalent organic nanosheet (TGDB-iCONs) was synthesized to selectively capture DA. TGDB-iCONs was prepared by one-step Schiff-base reaction of the charged monomer triaminoguanidine hydrochloride. It uniformly distributed positively charged guanidinium and negatively charged chloride ions on the surface, forming zwitterionic binding sites. The self-peeling of TGDB-iCONs facilitated the exposure of active sites and improved the adsorption efficiency. Several binding forces were generated between TGDB-iCONs and DA, including complementary electrostatic hydrophilic interactions, which were verified by density functional theory (DFT) calculation. TGDB-iCONs exhibited ultra-fast adsorption kinetics (7 min) and relatively high adsorption capacity (66.48 mg/g) for DA. Furthermore, TGDB-iCONs exhibit strong salt resistance, which is attributed to the charge “shielding” effect of the zwitterionic ions present in TGDB-iCONs. TGDB-iCONs could highly selectively enrich DA and detect trace DA from marine environment including seawater, algae and marine organisms and the limit of detection as low as 0.3 ng/kg. Significance and noveltyThis comprehensive study not only sheds light on the vast potential of ionic covalent organic frameworks nanosheets (iCONs) in supporting early warning, control, and traceability of DA, but also lays a solid foundation for future research endeavors aimed at designing and harnessing the unique properties of iCONs.

Insight into the Coextrusion Mechanism between Whey Protein Isolate and Cysteine.

The disulfide cross-linking sites of whey protein isolate (WPI) coextruded with dissolved cysteine (Cys) at concentrations of 0, 20, 40, 60, 80, and 100 mM were analyzed by liquid chromatography electrospray ionization tandem mass spectrometry (LC/MS/MS) combined with pLink software, and the structure and gel water distribution of WPI during coextrusion (≤50 °C) were also investigated. LC/MS/MS demonstrated that α-La (6) and α-La (120) were the most active sites for intermolecular disulfide cross-linking of α-La. Meanwhile, the molecular weight of protein polymers in coextruded WPI-Cys was the largest at 100 mM Cys, and α-lactalbumin was the main reactant for polymerization from the result of SDS-PAGE and size exclusion chromatography. Additionally, the high concentration of Cys caused the secondary structure of WPI to gradually change from a highly ordered to a disordered structure during coextrusion. In addition, with an increasing concentration of Cys, the free sulfhydryl group of proteins and the binding force to immobilized water gradually increased. Therefore, this work revealed the disulfide cross-linking mechanism between WPI and Cys under low-temperature coextrusion at the molecular level, and the obtained coextruded cross-linked WPI could serve as a novel food ingredient with excellent water-holding capacity for the food industry.

The aromatic amino acid phenylalanine: a versatile tool for binding transition metal ions.

The human body contains many different types of transition metal ions, such as Zn2+, Cu2+, which are involved in many physiological processes. An excess or deficiency of these ions can cause diseases, such as Alzheimer's disease, which is closely related to the levels of these ions in the body. In-depth understanding of various physiological and pathological mechanisms related to metal ions requires understanding the interaction between metal ions and nearby amino acids at the atomic level. This article selected four transition metal ions: Zn2+, Cu2+, Fe2+, and Mn2+ and the aromatic amino acid Phe, known for its strong coordination capability, as study subjects, comprehensively examining their binding situations. The results show that there are multiple binding modes between them and Phe, and most of the binding modes involve benzene ring coordination. The coordination strength order of the four metal ions with benzene ring, carbonyl O, hydroxyl O and amino N is different. For the lowest energy structure formed by each ion with Phe, all four ions are bound to N, carbonyl O, and benzene ring. Zn2+ is combined with two C's of the benzene ring, Cu2+ with four C's of the benzene ring, and Fe2+ and Mn2+ with the benzene ring as a whole. Part of the reason for this phenomenon may be derived from the tendency of transition metal ions to reach 18e stable structures when bound to ligands. There is a strong binding force between the four ions and Phe, and the binding trend is Cu2+(-294.9kcal/mol) > Zn2+(-261.3kcal/mol) > Fe2+(-247.5kcal/mol) > Mn2+(-220.2kcal/mol). Mayer bond order analysis and molecular orbital localization analysis found that there are very strong chemical interactions between transition metal ions and surrounding atoms, especially with N and carbonyl O. Several initial structures with different coordination modes to Phe were created according to chemical intuition for each divalent cation. Then semiempirical MD simulations at GFN2 level were run on these structures. The numerous generated structures were classified according to some criteria, then representative geometries were preliminarily optimized by TPSSh/6-31G*/LanL2DZ. To get more accurate electronic energies, high-precision quantum chemistry calculations at the level of TPSSh/def2TZVPP//TPSSh/def2QZVPP were carried out on the selected low-lying structures. All the optimized structures were confirmed to be minima without imaginary frequency by performing frequency analyses. Further electronic structure analyses such as IRI, Mayer bond order, IBSI etc. were performed to get more insights into the binding between the transition metal ions and Phe.

Study on the adsorption process and kinetic, thermodynamic of bio-based waste cattle hair powder toward acidic complex dye.

In this paper, cattle hair waste (CHW) was collected and physically milled into different meshes of ultrafine cattle hair powder (UCHP). The reuse of CHW reaches the purpose of treating pollution with waste by using bio-base adsorbent. It was characterized by using scanning electron microscope-energy dispersive spectrometer (SEM-EDS), Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), differential scanning calorimeter (DSC), and X-ray diffraction (XRD). The adsorption studies were carried out under different conditions of temperature, time, pH, concentration of dye solution, mesh size, and dosage of cattle hair powder, respectively. The pseudo-first and pseudo-secondary kinetics and intra-particle diffusion models were employed to analyze the adsorption kinetic. The Langmuir, Freundlich, and Temkin adsorption isotherm was used to analyze the adsorption isotherm. The results showed that the adsorption capacity of UCHP for acidic metal complex (Trupoxane Brown R6) dyes increased with the decreasing pH solution. The adsorption capacity of 200 mesh UCHP was 379.5mg.g-1 when the adsorption conditions were as follows: 100mL dye solution with the initial concentration of 1000mg·L-1, the dosage of adsorbent was 0.1g, the pH was 3 for 12h at 40°C. The kinetic model fitting results showed that the adsorption of dyes by UCHP conformed to the pseudo-second-order kinetic model. Adsorption thermodynamics study showed that the Langmuir model has the highest fitting result. The amino group contained on the surface of cattle hair powder and the amide bond contained in the molecular chain of peptide chain have better electrostatic adsorption binding force for acid metal complex dyes, and the binding between them is mainly electrostatic attraction. The experimental results show that the ultrafine powder has better adsorption property, which provides a high-value conversion way for recycling waste cattle hair.

Platelet Proteomics and Tissue Metabolomics Investigation for the Mechanism of Aspirin Eugenol Ester on Preventive Thrombosis Mechanism in a Rat Thrombosis Model.

Platelet activation is closely related to thrombosis. Aspirin eugenol ester (AEE) is a novel medicinal compound synthesized by esterifying aspirin with eugenol using the pro-drug principle. Pharmacological and pharmacodynamic experiments showed that AEE has excellent anti-inflammatory, antioxidant, and inhibitory platelet activation effects, preventing thrombosis. However, the regulatory network and action target of AEE in inhibiting platelet activation remain unknown. This study aimed to investigate the effects of AEE on platelets of thrombosed rats to reveal its regulatory mechanism via a multi-omics approach. The platelet proteomic results showed that 348 DEPs were identified in the AEE group compared with the model group, of which 87 were up- and 261 down-regulated. The pathways in this result were different from previous results, including mTOR signaling and ADP signaling at P2Y purinoceptor 12. The metabolomics of heart and abdominal aortic tissue results showed that the differential metabolites were mainly involved in steroid biosynthesis, the citric acid cycle, phenylalanine metabolism, phenylalanine, tyrosine, and tryptophan biosynthesis, and glutathione metabolism. Molecular docking results showed that AEE had a better binding force to both the COX-1 and P2Y12 protein. AEE could effectively inhibit platelet activation by inhibiting COX-1 protein and P2Y12 protein activity, thereby inhibiting platelet aggregation. Therefore, AEE can have a positive effect on inhibiting platelet activation.

Flavonoids as potential SARS-CoV-2 main protease inhibitors: In vitro activity evaluation, molecular docking, 3D-QSAR investigation and synthesis

The damage to public health posed by the COVID-19 epidemic remains non-negligible, and research into highly effective antiviral drugs is key to addressing the epidemic. The main protease (Mpro) is critical for SARS-CoV-2 replication and acts as an effective target for drug development. To date, many flavonoid compounds have been reported to exhibit inhibition of Mpro, and flavonoid structures are informative for the development of new inhibitors. In the present study, we first evaluated the ability of 35 flavonoid compounds to bind Mpro and found that the hydrophobic interaction generated between the benzene ring and the residues may be the main source of binding force. The in vitro inhibitory activity of these compounds was tested by the FRET method, and most of them showed significant inhibition of Mpro. Preliminary analysis revealed that the presence of the glycosidic group was detrimental to the activity of the compounds, in addition the position of the hydroxyl substituent had an effect on the activity of the compounds. Reliable and predictive CoMFA (q2 = 0.541, r2 = 0.998, SEE = 0.039) and CoMISA (q2 = 0.554, r2 = 0.999, SEE = 0.034) models were developed, and the compounds were analyzed by 3D-QSAR with modeled steric, electrostatic, hydrogen bond donor, and hydrophobic fields. A series of compounds were synthesized and characterized, which showed similar experimental and predicted activities, with the activity of 15d (IC50 = 0.74 ± 0.04 uM) exceeding that of the template molecule 15 (0.98 ± 0.13 uM). Subsequently, molecular docking revealed the binding mode of 15d to Mpro and verified the predictions of steric, hydrogen bond donor, and hydrophobic field. In conclusion, these findings provide ideas for subsequent structural studies of flavonoids that could be used in the development of flavonoid-type SARS-CoV-2 Mpro inhibitors.