Theranostics of skin neoplasms based on luminescence diagnostics in combination with photodynamic therapy in the absorption band of porphyrin

We report the results of developing a technique for theranostics of skin neoplasms based on luminescence diagnostics in combination with photodynamic therapy (PDT) in the absorption band of porphyrin. It is shown that the therapeutic effect is achieved exclusively due to PDT, without the participation of the hyperthermia process, which occurs at temperatures above 42 °C. The Fluroscan gel [based on the dipotassium salt of the ytterbium complex of 2,4-di-(a-methoxyethyl)deuteroporphyrin IX (Yb-DMDP)] is used as a preparation for theranostics. The main photophysical properties and possible mechanisms of accumulation of nanosized low-toxic photosensitisers based on this compound are studied. It is shown that the Yb-DMDP compound in a DMSO solution (30% aqueous DMSO) enhances photophysical characteristics (luminescence lifetime 5-10 ms, luminescence quantum yield up to 1%, extinction coefficient ~1.96 × 105 M-1 cm-1 at a wavelength of 398 nm). Experimental animals are used to test the proposed technique for theranostics of tumours using the Fluroscan gel and a fibre-optic laser fluorimeter.

USE OF ANALYSIS TECHNIQUE FOR IMMOBILIZED YEAST SACCHAROMYCES CEREVISIAE IN THE BIOTECHNOLOGICAL INDUSTRY

Article is devoted to the current state and problems of microbial cells immobilization and also prolonged storage of immobilized cells systems for the aims of biotechnological industry. In the experimental part immobilization conditions for the cells S. cerevisiae in alginate gel and vitality test, which had given high reproducibility of experimental results, were developed. Experimental results showed that viability of immobilized cells was higher than that of free yeast cells. It is possible that gel matrix has a protective effect on yeast cells during freezing. Comprehensive effect of cooling modes and preservation protective mediums, which contain sodium alginate, on viability of yeasts has been investigated. Advantage of yeast cells storage in immobilized state was shown experimentally. It was found that cooling mode and composition of preservation medium affect on the viability of S. cerevisiae cells during cryopreservation. In all freezing medium, both without protective components and with addition of a cryoprotective agent, the best results were obtained with cooling at a rate of 1°C/min. Viability indices in the samples were: 73.1 % – in distilled water; 90.8 % – in 1 % sodium alginate solution; 87.1 % – in 5 % DMSO solution and 86.1 % – in 1 % sodium alginate solution with the addition of 5 % DMSO. When cells were frozen in a 5 % DMSO solution and in a 1 % sodium alginate solution with the addition of 5 % DMSO, number of viable cells also decreased as cooling rate increased, but, probably, did not differ from the cell viability index in those samples that were frozen in 1 % sodium alginate solution. The highest results of viability for S. cerevisiae yeast cells were obtained during slow cooling for all cryoprotective mediums. For the first time, high cryoprotective properties of sodium alginate solution, were shown. Obtained results are enable to recommend the sodium alginate as a carrier for cryopreserved immobilized cells when using it in biotechnological processing for biologically active substances production.

Visual Detection of Triethylamine and a Dual Input/Output Logic Gate Based on a Eu3+-Complex

A series of Ln3+-metal centered complexes, Ln(TTA)3(DPPI) (Ln = La, 1; Ln = Eu, 2; Ln = Tb, 3; or Ln = Gd, 4) [(DPPI = N-(4-(1H-imidazo [4,5-f][1,10]phenanthrolin-2-yl)phenyl)-N-phenylbenzenamine) and (TTA = 2-Thenoyltrifluoroacetone)] have been synthesized and characterized. Among which, the Eu3+-complex shows efficient purity red luminescence in dimethylsulfoxide (DMSO) solution, with a Commission International De L’ Eclairage (CIE) coordinate at x = 0.638, y = 0.323 and ΦEuL = 38.9%. Interestingly, increasing the amounts of triethylamine (TEA) in the solution regulates the energy transfer between the ligand and the Eu3+-metal center, which further leads to the luminescence color changing from red to white, and then bluish-green depending on the different excitation wavelengths. Based on this, we have designed the IMPLICATION logic gate for TEA recognition by applying the amounts of TEA and the excitation wavelengths as the dual input signal, which makes this Eu3+-complex a promising candidate for TEA-sensing optical sensors.

Electrical and Electrochemical Studies of Polymer Gel Electrolytes Based on Agarose-LiBOB and P(VP-co-VAc)-LiBOB

This study focuses on preparation and characterization of polymer gel electrolytes (PGEs) based on agarose–LiBOB–DMSO and poly(1-vinylpyrrolidone-co-vinyl acetate)–LiBOB–DMSO. Two systems of PGEs were prepared by dissolving a different amount (1-8 wt.%) of agarose and (1-8 wt.%) P(VP-co-VAc) as host polymer in 0.8 M of LiBOB–DMSO solution. The addition of host polymer into 0.8 M of LiBOB–DMSO solution will result an optimum conductivity which is 6.91 x 10-3 S.cm-1 for agarose–LiBOB–DMSO system and 7.83 x 10-3 S.cm-1 for P(VP-co-VAc)–LiBOB–DMSO system. In the temperature range of conductivity studies discovered that the agarose–LiBOB–DMSO and P(VP-co-VAc)–LiBOB–DMSO polymer gel electrolytes abide by Arrhenius rule indicating that this PGEs could run at elevated temperature conditions. Furthermore, lithium transference number confirms that both electrolyte systems have 0.03 and 0.12 respectively at room temperature (298 K). Linear sweep voltammetry (LSV) measurements demonstrate the agarose–LiBOB–DMSO system has a potential of 4.26 V and P(VP-co-VAc)–LiBOB–DMSO system has a potential of 4.50 V which is good in electrochemical stability.

Chalcopyrite Leaching in a Dimethyl Sulfoxide Solution Containing Copper Chloride

Chalcopyrite (CuFeS2) is the most refractory copper mineral when treated in conventional sulfate media leaching systems. This is the first study to examine the use of a dimethyl sulfoxide (CH3SOCH3, DMSO) solution containing copper chloride (CuCl2) for the leaching of chalcopyrite. Leaching experiments for a copper concentrate composed mainly of chalcopyrite were conducted at ambient pressure at 313–413 K. The leaching fractions of Cu, Fe, S, Au, and As were investigated. It was found that 90% of the Cu was extracted in 2 h, and 94% was extracted in 4 h at 373 K, which is competitive with other conventional processes. A DMSO solution containing CuCl2 could selectively dissolve the valuable metals Cu and Au from chalcopyrite, but leave minerals with little economic value such as pyrite (FeS2) and As in the residue. Chalcopyrite is oxidized by cupric ion in proportion to the stoichiometric ratio of Cu in the concentrate to the initial cupric ion in the DMSO solution, which is enhanced by the presence of oxygen below 373 K.

Identifying the origin of the Voc deficit of kesterite solar cells from the two grain growth mechanisms induced by Sn2+ and Sn4+ precursors in DMSO solution

The large Voc deficit of kesterite solar cell mainly comes from the defective surface caused by multi-phase fusion grain growth; direct phase transformation grain growth produces high quality absorber with clean surface and thus high device Voc.