ПОЛУЧЕНИЕ И СВОЙСТВА ТОНКОПЛЕНОЧНЫХ КОМПОЗИЦИОННЫХ ПОЛОВОЛОКОННЫХ МЕМБРАН ДЛЯ УЛЬТРАФИЛЬТРАЦИИ С НИЗКИМ НОМИНАЛЬНЫМ МОЛЕКУЛЯРНО-МАССОВЫМ ПРЕДЕЛОМ ОТСЕЧЕНИЯ

Fullerenol C60(OH)24 was incorporated into a polyamide (PA) selective layer to develop novel thin film nanocomposite (TFN) hollow fiber membranes for low molecular weight cut-off ultrafiltration. TFN membranes were fabricated using the interfacial polycondensation technique by alternately pumping a fullerenol dispersion into the triethylenetetramine (TETA) aqueous solution and the isophthaloyl chloride solution into hexane through polysulfone hollow fiber membranes. The contact angle of the skin layer was found to decrease sharply from 34 to 21° when the concentration of fullerenol increases up to 0.5 wt. % in the TETA aqueous solution. Antifouling properties of the PA/fullerenol membranes were found to be superior to the initial membrane. The maximum fouling recovery ratio was observed for the TFN membrane with 0.3–0.75 wt. % of fullerenol in the TETA aqueous solution. Тонкопленочные композиционные мембраны (ТКМ) для ультрафильтрации с низким номинальным молекулярно-массовым пределом отсечения были получены при введении добавок фуллеренола C60(OH)24 в селективный полиамидный (ПА) слой, сформированный методом межфазной поликонденсации при использовании в качестве подложки половолоконной ультрафильтрационной мембраны на основе полисульфона. Межфазную поликонденсацию с образованием тонкого полиамидного слоя проводили при последовательной фильтрации раствора триэтилентетрамина (ТЭТА) в воде и раствора изофталоилхлорида в гексане через половолоконную мембрану. При увеличении концентрации фуллеренола в водном растворе ТЭТА угол смачивания селективного слоя уменьшается с 34 до 21°. Показано, что устойчивость к засорению ТКМ ПА/фуллеренол выше, чем исходной немодифицирован- ной мембраны. Мембраны, полученные с использованием 0,3–0,75 % дисперсий фуллеренола в растворе ТЭТА, характеризовались максимальным значением восстановления потока после фильтрации раствора лизоцима.

A high-power source of ultrawideband pulses of synthesized radiation

A high-power source of ultrawideband radiation based on the synthesis of electromagnetic pulses with different frequency bands has been created. A four-channel former of highly stable bipolar pulses with durations of 0.5 and 1 ns was developed. Each element of a 2 × 2 array of combined antennas was excited from its former channel. Two modes of radiation synthesis were studied: according to the maximum field strength and the maximum spectrum width. For the first mode, radiation pulses with a frequency band of 0.39–2.13 GHz and an effective potential of 600 kV were obtained. Synthesized radiation pulses with an extended frequency band of 0.15–2.7 GHz and an effective potential of 200 kV were obtained in the second mode. The pulse repetition frequency was 100 H

Study of Lercanidipine Drug Release from Medicine in Combination with Ramipril <i>in vitro</i> and <i>in vivo

Introduction. Hypertension is the most common non-infectious disease in the world. New clinical recommendations for the diagnosis and management of patients with arterial hypertension are considering the issue of prescribing combination therapy and prefer fixed combinations of drugs in a single pill. The study of the pharmacokinetics of medicinal substances and the consideration of their pharmacokinetic parameters today is a necessary step in the complex of work, both in the creation of new original medicines and in the application of known generic drugs, and this is primarily due to obtaining objective characteristics of all processes occur in the body of the animal (human) with the drug. Pharmacokinetics is assessed in individual studies or as part of efficacy, safety, and tolerability studies.Aim. The study of the release of lercanidipine from bilayer tablets containing two API (ramipril and lercanidipine) in the dissolution medium used for quality control in vitro and release in vivo, after oral administration of the drug to rabbits.Materials and methods. Studies have been conducted on the release of lercanidipine from the combined drug in vitro and in vivo. As a test system were used laboratory rabbits Soviet chinchilla breed. Pharmacokinetic parameters were determined.Results and discussion. A graph of the release of lercanidipine from the combined drug was constructed and the dependence of the concentration of this substance in the blood plasma of rabbits on time was revealed. Calculated pharmacokinetic parameters. An in vivo release study shows that the pharmacokinetics of lercanidipine are consistent with literature data.Conclusion. The test drug has all the advantages of a rational fixed combination of antihypertensive drugs and simplifies therapy, meets the requirements of the latest clinical guidelines

COMPARATIVE EFFICIENCY OF CYTOCHROME C EYE DROPS DURING EXPERIMENTAL EYE DAMAGE

Introduction. Cytochrome C is a metabolic drug that has an antihypoxic, trophic effect, stimulates regeneration processes, and is also used in various eye diseases.Aim. The task of the work was to determine the specific activity of cytochrome C eye drops in comparison with emoxipin.Materials and methods. As a test system, Soviet chinchilla male rabbits were used, the simulation of traumatic erosion and acid burn was carried out, followed by the use of test eye drops. In forming erosion, the method of C. Hanna, J. E. O'Brien (1960) with scraping of the corneal epithelium, an acid burn in the experiment was formed under local anesthesia (0.4% inocain) application of filter paper (in the form of a circle with a diameter of 8 mm) moistened with 3% acetic acid solution with an exposure of 5 seconds on the cornea. The effectiveness evaluation was carried out on the basis of a scale proposed by the authors, which allows histologically to take into account corneal changes during the pathological process. Descriptive statistics methods were used for all quantitative data: the average sample values (M) and standard deviations (SD) were calculated. The distribution in each data sample was analyzed using the Shapiro – Wilk criterion. Under normal distribution, analysis of variance was used followed by a posteriori analysis (Tukey criterion). If the data had an abnormal distribution, the Kruskal-Wallis test was calculated.Results and discussion. The integrity of the patterns of traumatic erosion and acid burn was histologically confirmed. The therapeutic efficacy of eye drops of emoxipin in the full dose was not sufficiently pronounced and comparable to that of cytochrome C in half the therapeutic dose. Cytochrome C in therapeutic and dual therapeutic dose effectively coped with the effects of acid burn and traumatic erosion when used in the form of eye drops for 28 days.Conclusion. Cytochrome C eye drops, used at a therapeutic dose and a dose exceeding the therapeutic dose 2 times, have a pronounced regenerative effect in traumatic erosion and acid burn of the rabbit eye cornea. The effect of Cytochrome C eye drops at half the therapeutic dose, as well as the reference drug (emoxipin) at the therapeutic dose, is not very pronounced

Synthesis of Aromatic Polyimides Based on 3,4&prime;-Oxydianiline by One-Pot Polycondensation in Molten Benzoic Acid and Their Application as Membrane Materials for Pervaporation

A series of aromatic polyimides based on the asymmetrical diamine 3,4&#884;-oxydianiline and various tetracarboxylic acid dianhydrides, both &ldquo;rigid&rdquo; and &ldquo;flexible&rdquo; structure, have been synthesized using the original method of one-pot high-temperature catalytic polycondensation in molten benzoic acid. The synthesized polyimides were investigated using fourier-transform infrared (FTIR) and 1H NMR spectroscopy, gel permeation chromatography (GPC), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), thermomechanical analysis (TMA) and wide-angle X-ray scattering (WAXS). It was found that the synthesized polyimides, depending on the used dianhydride, are characterized by different solubility in organic solvent and molten benzoic acid, molecular weight, glass transition temperature (Tg) from 198 to 270 &deg;C, an amorphous or semi crystalline structure with the degree of crystallinity from 41 to 52%. The influence of the method of synthesis on the formation of the crystalline phase of polyimides was studied, and the obtained results were compared with the literature data. The effect of dianhydride chemical structure on the performance of polyimide in pervaporation more specifically, dehydratation of azeotropic isopropanol solution was investigated and compared with the commercially available polyetherimide Ultem 1000&trade;. Membrane structure was studied using scanning electron microscopy. It was found that polyimide PI-DA is the most effective for separation of 88 wt.% isopropanol/12 wt.% water mixture compared to the polyimide PI-6FDA and commercial polyetherimide Ultem 1000&trade; demonstrating normalized permeation flux of 2.77 kg &micro;m m&minus;2 h&minus;1 and separation factor of 264 (water content in permeate 97 wt.%)

One-Step Preparation of Antifouling Polysulfone Ultrafiltration Membranes via Modification by a Cationic Polyelectrolyte Based on Polyacrylamide

A novel method for one-step preparation of antifouling ultrafiltration membranes via a non-solvent induced phase separation (NIPS) technique is proposed. It involves using aqueous 0.05&ndash;0.3 wt.% solutions of cationic polyelectrolyte based on a copolymer of acrylamide and 2-acryloxyethyltrimethylammonium chloride (Praestol 859) as a coagulant in NIPS. A systematic study of the effect of the cationic polyelectrolyte addition to the coagulant on the structure, performance and antifouling stability of polysulfone membranes was carried out. The methods for membrane characterization involved scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), contact angle and zeta-potential measurements and evaluation of the permeability, rejection and antifouling performance in human serum albumin solution and surface water ultrafiltration. It was revealed that in the presence of cationic polyelectrolyte in the coagulation bath, its concentration has a major influence on the rate of &ldquo;solvent&ndash;non-solvent&rdquo; exchange and thus also on the rate of phase separation which significantly affects membrane structure. The immobilization of cationic polyelectrolyte macromolecules into the selective layer was confirmed by FTIR spectroscopy. It was revealed that polyelectrolyte macromolecules predominately immobilize on the surface of the selective layer and not on the bottom layer. Membrane modification was found to improve the hydrophilicity of the selective layer, to increase surface roughness and to change zeta-potential which yields the substantial improvement of membrane antifouling stability toward natural organic matter and human serum albumin