Solubility Determination,Hansen Solubility Parameters and Thermodynamic Evaluation of Thymoquinone in (Isopropanol + Water) Compositions

This article studies the solubility, Hansen solubility parameters (HSPs), and thermodynamic behavior of a naturally-derived bioactive thymoquinone (TQ) in different binary combinations of isopropanol (IPA) and water (H₂O). The mole fraction solubilities (x₃) of TQ in various (IPA + H₂O) compositions are measured at 298.2–318.2 K and 0.1 MPa. The HSPs of TQ, neat IPA, neat H₂O, and binary (IPA + H₂O) compositions free of TQ are also determined. The x₃ data of TQ are regressed by van’t Hoff, Apelblat, Yalkowsky–Roseman, Buchowski–Ksiazczak λh, Jouyban–Acree, and Jouyban–Acree–van’t Hoff models. The maximum and minimum x₃ values of TQ are recorded in neat IPA (7.63 × 10⁻² at 318.2 K) and neat H₂O (8.25 × 10⁻⁵ at 298.2 K), respectively. The solubility of TQ is recorded as increasing with the rise in temperature and IPA mass fraction in all (IPA + H₂O) mixtures, including pure IPA and pure H₂O. The HSP of TQ is similar to that of pure IPA, suggesting the great potential of IPA in TQ solubilization. The maximum molecular solute-solvent interactions are found in TQ-IPA compared to TQ-H₂O. A thermodynamic study indicates an endothermic and entropy-driven dissolution of TQ in all (IPA + H₂O) mixtures, including pure IPA and pure H₂O.     

Direct eicosanoid profiling of the hypoxic lung by comprehensive analysis via capillary liquid chromatography with dual online photodiode-array and tandem mass-spectrometric detection

Eicosanoids are arachidonic acid-derived mediators, with partly contradictory, incompletely elucidated actions. Thus, epoxyeicosatrienoic acids (EETs) are controversially discussed as putative vasodilatative endothelium-derived hyperpolarizing factors in the cardiovascular compartment but reported as vasoconstrictors in the lung. Inconsistent findings concerning eicosanoid physiology may be because previous methods were lacking sensitivity, identification reliability, and/or have focused on special eicosanoid groups only, ignoring the overall mediator context, and thus limiting the correlation accuracy between autacoid formation and bioactivity profile. Therefore, we developed an approach which enables the simultaneous assessment of 44 eicosanoids, including all representatives of the arachidonic acid cascade, i.e., cytochrome P450, lipoxygenase, cyclooxygenase products, and free isoprostanes as in vivo markers of oxidative stress, in one 50-minute chromatographic run. The approach combines (i) source-specific sample extraction, (ii) rugged isocratic and high-sensitivity capillary liquid-chromatographic separation, and (iii) reliable dual online photodiode-array and electrospray ionization tandem mass-spectrometric identification and quantitation. High sensitivity with limits of quantification in the femtogram range was achieved by use of capillary columns with typical high peak efficiency, due to small inner diameters, and virtually complete substance transfer to the mass spectrometer, due to flow rates in the low microliter range, instead of large inner diameter columns with low chromatographic signal and only partial analyte transfer employed by previous methods. This expeditious, global and sensitive technique provides the prerequisite for new, accurate insights regarding the physiology of specific mediators, for example EETs, in the context of all relevant vasoactive autacoids under varying conditions of oxidative stress by direct comparison of all eicosanoid generation profiles. Indeed, application of comprehensive “eicoprofiling” to hypoxically ventilated rabbit lungs revealed at a glance the enhanced biosynthesis of free EETs in the overall mediator generation context, thus suggesting their hypothetical contribution to hypoxic pulmonary vasoconstriction. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Probing Charge-Transfer Processes in a Covalently Linked [Ge9]-Cluster Imine Dyad

C₆₀ donor dyads in which the carbon cage is covalently linked to an electron-donating unit have been discussed as one possibility for an electron-transfer system, and it has been shown that spherical [Ge₉] cluster anions show a close relation to fullerenes with respect to their electronic structure. However, the optical properties of these clusters and of functionalized cluster derivatives are almost unknown. We now report on the synthesis of the intensely red [Ge₉] cluster linked to an extended π-electron system. [Ge₉{Si(TMS)₃}₂{CH₃C=N}-DAB(II)^Dipp]⁻ ( 1⁻ ) is formed upon the reaction of [Ge₉{Si(TMS)₃}₂]²⁻ with bromo-diazaborole DAB(II)^Dipp-Br in CH₃CN (TMS=trimethylsilyl; DAB(II)=1,3,2-diazaborole with an unsaturated backbone; Dipp=2,6-di-iso-propylphenyl). Reversible protonation of the imine entity in 1⁻ yields the deep green, zwitterionic cluster [Ge₉{Si(TMS)₃}₂{CH₃C=N(H)}-DAB(II)^Dipp] ( 1-H ) and vice versa. Optical spectroscopy combined with time-dependent density functional theory suggests a charge-transfer excitation between the cluster and the antibonding π* orbital of the imine moiety as the cause of the intense coloration. An absorption maximum of 1-H in the red region of the electromagnetic spectrum and the corresponding lowest-energy excited state at λ=669 nm make the compound an interesting starting point for further investigations targeting the design of photo-active cluster compounds.     

Electrochemical Monitoring of Saos‐2 Cell Differentiation on Pyrolytic Carbon Electrodes

In this study we establish an electrochemical platform based on two dimensional (2D) pyrolytic carbon electrodes for in vitro analysis of osteoblast differentiation. Electrochemical impedance spectroscopy (EIS) was used to monitor cell adhesion and proliferation, while an electrochemical assay based on square wave voltammetry (SWV) was applied to measure the activity of the differentiation marker alkaline phosphatase (ALP). 2D pyrolytic carbon electrodes were fabricated and used to monitor Saos‐2 cell differentiation for a period of up to 21 days. With this method it was possible to detect a faster increase of ALP activity for cells cultured in medium supplemented with differentiation factors compared to cells cultured in growth medium. This was confirmed by the results obtained with Alizarin Red staining, showing that cells subjected to osteogenic medium went through the entire differentiation process, from proliferation to mineralization. Finally, for the first time, real‐time monitoring of ALP activity combined with continuous EIS monitoring of the same cell culture was achieved using the pyrolytic carbon electrodes.     

Integrated experimental and computational approach for nanoparticle flow analysis

We report a new method combining computational fluid dynamics and flow experiments with customized channels to understand the transport of nanoparticles. Iron oxide nanoparticles, being highly attractive for biomedical research are chosen as model nanoparticles for the transport studies. Four different polyvinyl pyrrolidone and polyethyleneimine coated iron oxide nanoparticles of hydrodynamic sizes ranging from 45–178 nm were synthesized. These nanoparticles were adjusted to different target mass concentrations and ran through a bent tube to determine flow velocity and mass loss, specific to the nanoparticles. Computational predictions were made for velocity and mass loss of fully developed flow of nanoparticles through bent channel, which compared well with experimental measurements. A diffusion dominated nanoparticle flow is predicted, based on our results. This work will provide a breakthrough for further experimental and computational research to help understand the nanoparticle targeted delivery and the design of nanoparticles for optimal delivery in biomedical applications.     

Mn3O4包覆对LiNi0.5Mn1.5O4正极材料界面电化学性能的提高

本文采用化学湿磨法，首次将金属氧化物Mn₃O₄包覆于LiNi_0.5Mn_1.5O₄颗粒表面，使得电极材料的电子电导率从1.53×10^-7 S/cm 提高到3.15×10^-5 S/cm. 电化学测试结果表明Mn₃O₄包覆大大提高LiNi_0.5Mn_1.5O₄正极材料的倍率性能和高温循环稳定性. 最佳包覆样品为2.6wt% Mn₃O₄包覆的LiNi_0.5Mn_1.5O₄，在10 C倍率下具有108 mAh/g的高放电容并且在55 °C下100次循环后仍有78%的容量保持率，远大于未包覆样品67%的容量保持率.     

Certain Results for the 2-Variable Peters Mixed Type and Related Polynomials

In this article, the 2-variable general polynomials are taken as base with Peters polynomials to introduce a family of 2-variable Peters mixed type polynomials.These polynomials are framed within the context of monomiality principle and their properties are established. Certain summation formulae for these polynomials are also derived. Examples of some members belonging to this family are considered and numbers related to some mixed special polynomials are also explored.     

Molecular complexes of aspirin with humic acid extracted from shilajit and their characterization

Aspirin possesses antipyretic, anti-inflammatory, analgesic and anti-aggregatory activity. The acetylsalicylic acid molecule has a carboxyl group and an ester group. The ester group can be easily hydrolyzed, which reduces the medicinal value and causes side effects on humans. The aim of the present study was to prepare solid complexes between aspirin and humic by lyophilization and solvent evaporation technique in the molar ratio 1:1 and 1:2. Molecular interaction between aspirin and humic acid were studied by DSC, XRD, FT-IR and scanning electron microscopy. This technique clearly demonstrated the existence of solid inclusion complex formation. The lyophilized complex in the molar ratio 1:2 showed enhanced stability and dissolution rates of aspirin significantly. A highly significant (p < 0.05) anti-inflammatory action of the treatment of optimized freeze dried (1:2) aspirin complex with humic acid was evidenced by inhibition of rat paw edema and anti-ulcerogenic action was measured by lowest score (0.63 ± 0.10) with significant reduction in ulceration as compared to aspirin alone.     

On the Gauge and BRST Invariance of the Chiral QED with Faddeevian Anomaly

Chiral Schwinger model with the Faddeevian anomaly is considered. It is found that imposing a chiral constraint this model can be expressed in terms of chiral boson. The model when expressed in terms of chiral boson remains anomalous and the Gauss law of which gives anomalous Poisson brackets between itself. In spite of that a systematic BRST quantization is possible. The Wess-Zumino term corresponding to this theory appears automatically during the process of quantization. A gauge invariant reformulation of this model is also constructed. Unlike the former one gauge invariance is done here without any extension of phase space. This gauge invariant version maps onto the vector Schwinger model. The gauge invariant version of the chiral Schwinger model for a=2 has a massive field with identical mass however gauge invariant version obtained here does not map on to that.     

Highly efficient and green esterification of carboxylic acids in deep eutectic solvents without any other additives

A protocol that carboxylic acids esterifies with the quaternary ammonium salt of deep eutectic solvent (DES) is presented, which opens a new access to ester using DES as alkylating agent, solvent, and catalyst. The reaction runs smoothly in DES without any other additives. Substituted cinnamic acids, aromatic acids, and aliphatic acids can be esterified in moderate to good yields. The advantages of this reaction include excellent functional group compatibility and simple reaction procedure.