Erratum to: “Effect of the Conditions of Anodizing on the Morphology of Nanotitania”

Russian Journal of Physical Chemistry A - The list of authors and their affiliations should read: N. V. Roota, b, D. Yu. Kultina, L. M. Kustova, b, I. K. Kudryavtseva, and O. K. Lebedevaa,*...     

Erratum on “An efficient method for computing excess free energy of liquid”

Science China Chemistry - In the above referenced publication [1], there is a mistake in the derivation process leading to the final formula for computing excess free energy of liquids, i.e., Eq....     

Correction to the paper “the condition of mechanical equilibrium on the surface of a nonuniform thin film” [1]

The correction is introduced to the definition of the disjoining pressure of wedge-shaped film formulated in the authors’ previous publication. In refined definition, the nondiagonal pattern of pressure tensor even in cylindrical coordinates is taken into account and the disjoining pressure is introduced by analogy with the case of the transition zone of wetting meniscus. The alternative procedure of the definition of the disjoining pressure through the diagonal pressure tensor in the middle of the wedge is also considered.     

A facile approach to synthesize a “star-like” material based on β-cyclodextrin for enhancing the flowability of paraffinic oils

A novel compound, which exhibits “star-like” architecture and is expected to be a promising flow improver for paraffinic oils, was presented in the current work. This material was facilely synthesized based on β-cyclodextrin molecule via a catalytic esterification procedure under mild experiment conditions. The chemical formation was characterized by FT-IR, ¹H-NMR, and elemental analysis, respectively. The experimental data revealed that each β-cyclodextrin was attached by approximately seven C14 chains. This type of architecture is supposed to be appropriate to co-crystallize with paraffin melocules through taking the place of a paraffin in crystal lattic and thus disperse the agglomeration of wax crystals. This hypothesis was verified through a yield stress test and rheological analysis. It was observed that after treatment with this compound, the paraffinic oil yielded at a much lower stress value compared to the untreated oil. Moreover, a significant shift of the apparent viscosity vs. temperature curve to the left field occurred. These results demonstrated the capacity of this synthesized compound in enhancing the flowability of paraffinic oils.     

Influence of impurity elements on the corrosion of α-uranium surface: a density functional theory study

Journal of Radioanalytical and Nuclear Chemistry - Influence of substitutional Fe, Al and Mg atoms on the corrosion of α-U(110) surface was studied by DFT?+?U method. The...     

Bioconjugation of the estrogen receptor hERα to a quantum dot dye for a controlled immobilization on a SiO2 surface

We investigated the immobilization of the estrogen receptor hER(α) on silanized SiO(2) surfaces for biosensor applications. The conjugation of the estrogen receptor hER(α) to the quantum dot dye QD655 was achieved. In order to obtain an optimal immobilization of the estrogen receptor hER(α) on the functionalized SiO(2) surface, the bioconjugate hER(α)-QD655 (Rcpt-qd655) solution was prepared with a higher molar ratio of 10-15 between the QDs and the receptors. A blue laser with an excitation wavelength of 405 nm was used for photoluminescence spectroscopy (PL) investigations to monitor the bioconjugate Rcpt-qd655 immobilization on the silanized SiO(2) surfaces with three different functional groups, namely NH(2), -COO(-), and -SH. Several wash processes were applied to remove the excess receptors from the surface after the immobilization. A Fourier transform infrared spectroscopy (FTIR) was used to control the biofilm background after each wash of the receptor-coated surface which allows the optimization of the immobilization protocol. In order to test its stability a quartz crystal microbalance (QCM) was employed and the receptor density was calculated. Finally the optimal biolayer (silane film+hER(α) receptor) was tested for measurements of 17?-estradiol (E2) with a concentration of 1 μM in waterish solution. The measurement concept outlined in [L. Rebohle et al., Vacuum 83 (2009) 24-28] was applied. The whole system was investigated by PL, which exhibits two color signals, namely from the receptor and the detected E2 molecules.     

Tracking the multiple-step formation of an iron(Ⅲ) complex and its application in photodynamic therapy for breast cancer

A tandem reaction of pyridin-2-ylmethanamine(L1′) with 8-hydroxyquinoline-2-carbaldehyde(HL1) assisted by FeCl_3 was observed to give the new nitrogen heterocycle HL3(HL3=2-(imidazo[1,5-a]pyridin-3-yl)quinolin-8-ol) as its Fe(Ⅲ) complex,[Fe(L3)Cl_2](Fe1). Electrospray ionization mass spectrometry(ESI-MS) reveals its formation involves three steps:(1) coordination of both HL1 and L1′ to Fe,(2) aldehyde-amine coupling, and(3) ring closure. The results of electronic absorption spectroscopy, cyclic voltammetry, and density functional theory(DFT) calculations show the proximity of the optical transition energy to that of the excitation of ~3O_2 to ~1O_2, which prompted us to explore its application as a photosensitizer for photodynamic therapy(PDT). Photo-toxicity studies show that Fe1 exhibits the highest anti-proliferation efficiency in human breast cancer MDA-MB-231 cells under light irradiation. Moreover, studies with orthotopic models of breast cancer further expounded the anti-tumor activity of Fe1 with no significant toxicity to other organs and low retention in the body.     

Answer to “comment on the Raman study of the thermal transformation of calcium hydroxide”

Despite the arguments used by Dr. Seehra against our interpretations about the Raman study of Ca(OH)₂, the second-order Raman spectrum of CaO cannot be observed because of the finely divided state of the material produced by thermal dehydration of the hydroxide. This study is in progress and some new results are announced.     

Erratum to: “Silicon nanopowder as active material for hybrid electrodes of lithium-ion batteries”

Russian Journal of Applied Chemistry -     

Using ab initio “data” to accurately determine the fourth density virial coefficient of helium

We combine accurate ab initio calculations of the second and third density virial coefficients, B(T) and C(T), of ⁴He with measurements of its (p–ρ–T) behavior to determine the fourth density virial coefficient D(T). The measurements were made with a two-sinker, magnetic-suspension densimeter at pressures up to 38 MPa. The measurements on isotherms from T = 223 K to T = 323 K were previously published; new measurements from T = 323 K to T = 500 K are presented here. On each isotherm, a regression of the virial expansion was constrained to the ab initio values of B(T) and C(T); the regression determined D(T) as well as two apparatus-dependent parameters that compensated for systematic errors in the measurements. The percentage uncertainties of D(T) ranged from 2.6% at T = 223 K to 9.5% at T = 400 K to 24.7% at T = 500 K, where these uncertainties are expanded uncertainties with coverage factor of k = 2 corresponding to a 95% confidence interval. These uncertainties are 1/6th of the uncertainty obtained without the ab initio values of B(T) and C(T). The apparatus-dependent parameters can be used to calibrate the densimeter, and this will reduce the uncertainty of other measurements made with this two-sinker densimeter. The new values of D(T) will find applications in accurate gas metrology, such as a primary pressure standard based on the refractive index of helium.     

A Complete Solution to a Conjecture on the β-Polynomials of Graphs

In 1990, Gutman and Mizoguchi conjectured that all roots of the -polynomial (G,C,x) of a graph G are real. Since then, there has been some literature intending to solve this conjecture. However, in all existing literature, only classes of graphs were found to show that the conjecture is true; for example, monocyclic graphs, bicyclic graphs, graphs such that no two circuits share a common edge, graphs without 3-matchings, etc, supporting the conjecture in some sense. Yet, no complete solution has been given. In this paper, we show that the conjecture is true for all graphs, and therefore completely solve this conjecture.     

Exploration on the Biotechnological Aspect of the Ureolytic Bacteria for the Production of the Cementitious Materials—a Review

Biomineralization is a process that leads to the formation of minerals using the biologically or biotechnologically mediated route. Calcium carbonate is one such biomineral that is secreted by the ureolytic bacteria which contributes for the strengthening and improvement of cementitious and sandy materials. It is a new and innovative area in the geotechnological engineering and structural engineering due to its wide range of implications in strengthening of soil, sand, stone, and cementitious materials. The shape and size of the calcium carbonate particle vary with the strain of the bacterium used, and it is species specific. This paper aims in the critical review of the mechanism of calcium carbonate precipitation by the bacterium, various bacteria involved, and the useful outputs of the technique of biomineralization. Based on the critical review, it also recommends the future development and research in the field to develop a technology that can strengthen the existing and the proposed structures.     

Synthesis and Characterization of PEG-scuteilarin Conjugates, a Potential PEG Ester Prodrug for the Oral Delivery of Scutellarin

Highly water soluble esters of scutellarin with variable molecular weight polyethylene glycol （PEG） were prepared via PEGylation. The physicochemical properties and the stabilities under different conditions were investigated. By PEG modification, the greatly increased water solubility and desirable partition coefficient of scuteUarin were obtained, and the results showed that these conjugates were potential prodrugs for the oral delivery of scuteUarin.     

Studies on the Performance and Structure of Supported Catalysts for the Partial Oxidation of Methane to Syngas

The catalytic properties of several supported metal catalysts on different carriers were studied in the partial oxidation of methane (POM) to syngas. In our experiment, supported noble metal catalysts exhibited better performance than the other supported transition metal catalysts. The catalyst performances were significantly influenced by the d-electron configuration of the active metal components and the dispersion of active metal components on the support. A catalyst with a moderate number of unpaired electrons in the d-orbital of the active metal support without obvious acidity or redox activity (e.g. MgO) was suitable for POM performance. The Rh/SiO2 catalyst was the best in the POM reaction, among those investigated. Reaction conditions apparently also affected the POM performance of the catalyst. The conversion of methane and the selectivity for CO increased with the reaction temperature, and a high CH4/O2 ratio was not beneficial for POM performance.     

Synthesis and Characterization of PEG-scutellarin Conjugates, a Potential PEG Ester Prodrug for the Oral Delivery of Scutellarin

Scutellarin is the active ingredient extracted from Erigeron breviscapus, a traditional Chinese herbal medicine. Pharmacological study showed that scutellarin could significantly reduce the blood viscosity, improve the blood flow, decrease the vascular re…     

Influence of the chain stiffness on the thermodynamics of a Gō-type model for protein folding

The relative importance of local and long range interactions in the characteristics of the protein folding process has long been a matter of controversy. Computer simulations based on Gō-type models have been widely used to study this topic, but without much agreement on which type of interactions is more relevant for the foldability of a protein. In this work, the authors also employ a topology-based potential and simulation model to analyze the influence of local and long range interactions on the thermodynamics of the folding transition. The former are mainly used to control the degree of flexibility (or stiffness) of the chain, mostly appreciable in the unfolded (noncompact) state. Our results show the different effects that local and nonlocal interactions have on the entropy and the energy of the system. This implies that a balance between both types of interactions is required, so that a free energy barrier exists between the native and the denatured states. The variations in the contribution of both types of interactions have also a direct effect on the stability of the chain conformations, including the possible appearance of thermodynamic folding intermediates.