Innovative quality improvements in hotel services

The paper is devoted to the development of approaches for the improvement of quality of hotel services on innovative basis. It has been established that in the market of hotel services, innovations are being introduced successfully for the purpose of attracting as many customers as possible. All this ensures development of new technologies of constructing hotels, appearance of new market segments satisfying a diverse demand of visitors. It has been proved that to improve the quality of hotel services, it is necessary to develop a strategy and tactics of development of hotel business on innovative basis. It has been determined that introduction of innovations must be realised both at the level of the state and at the level of separate hotels. Further innovative growth will allow improving the quality of hotel services in the world market of hotel real estate. However, this is possible in case of normalization of the economic and political situation in the country and creation of conditions for investment attractiveness in hotel business.peer-reviewe

LIGHT SCATTERING IN RESEARCH AND QUALITY CONTROL OF DEUTERIUM DEPLETED WATER FOR PHARMACEUTICAL APPLICATION

Objective: Development of a methodology for measuring the deuterium content in water for pharmaceutical purposes by laser light scattering based on ideas about the cluster structure of water. Methods: Samples of industrially manufactured drinking water from different manufacturers with varying deuterium content from 10 ppm to 115 ppm. For the titration of laboratory samples of deuterium depleted water in increments of 5 ppm the following reagents were used: Water, deuterium-depleted (≤1 ppm (D2O, Aldrich, USA); Deuterium oxide/Heavy water/Water-d2 (99.9 atom % D, Aldrich, USA); water Milli-Q (specific resistance 18.2 µS·sm at 25 оС, ТОС ≤ 5 ppb, Merck Millipore). The determination of deuterium content in samples of industrially manufactured water and water obtained in a laboratory manner was carried out by the method of low-angle laser light scattering (LALLS) at the Mastersizer (Malvern Instruments) analyzer and using a working measuring tool–laser dispersion meter/MDL («Cluster-1», Russia/Ukraine). The statistical methods–packages OriginPro®9. Results: It was found that the content of isotopologies in water leads to physicochemical water’s properties changes and morphology changes of giant heterogeneous clusters (GHC). The results of low-angle laser light scattering (LALLS) in the water samples under investigation showed the dependence of the water GHC "dispersibility" expressed in the differentiation of curves of the volume size distribution ("size spectra"), the volume concentration, w%, the laser obscuration values (I ‒I0) as the function of the water isotopic composition variations. The laser diffraction method results correlate with two-dimensional (2D) multi-descriptor mathematical analysis. Conclusion: When identifying deuterium depleted water, it should be considered not only the indicators that determine its pharmacopoeial quality, but also the D/H ratio, because even small changes in the natural isotopic composition of water lead to significant biological effects. Our proposed approach using laser diffraction in combination with mathematical apparatus of (2D) multi-descriptor laser scattering analysis makes possible the exact calculation of individual signs of deuterium depleted water as the pharmaceutical object of study

PHYSICOCHEMICAL PROPERTIES AND BIOLOGICAL ACTIVITY OF THE NEW ANTIVIRAL SUBSTANCE

Objective: To develop a set of quality control procedures for the promising antiviral pharmaceutical substance L-histidyl-1-adamantylethylamine dihydrochloride monohydrate, a derivative of rimantadine. Methods: Substances and solvents: synthesized in laboratory L-histidyl-1-adamantylethylamine dihydrochloride monohydrate (H-His-Rim•2HCl•H2O), rimantadine hydrochloride (Rim•HCl), 99%, ethanol 96%, N, N-dimethylformamide (DMF) anhydrous, 99.8% and n-hexane anhydrous, 95%, deionized high-resistance water (18.2 MΩ•cm at 25 °C, Milli-Q system), silver nitrate. Infrared (IR) Spectroscopy–Cary 630 Fourier Transform IR Spectrometer, elemental analysis–elemental composition analyzer CHNS-O EuroEA3000, ultraviolet (UV) spectrometry–Cary-60 spectrophotometer, polarimetry–POL-1/2 polarimeter with an external Peltier module, granulometric analysis by optical microscopy (Altami BIO 2 microscope) and low-angle laser light scattering (LALLS)–Master Sizer 3600, measurement of potential for hydrogen–potentiometer PB-11, Spirotox method–the study of temperature dependences of Spirostomum ambiguum lifetime to characterize the biological activity of the studied compounds. Results: The substance H-His-Rim•2HCl•H2O is an amorphous yellowish powder, slightly soluble in water, soluble in ethanol, freely soluble in N, N-dimethylformamide, and practically insoluble in n-hexane. A study of the elemental composition has confirmed the authenticity of H-His-Rim•2HCl•H2O. Comparison of the spectral characteristics of H-His-Rim•2HCl•H2O and Rim•HCl by IR spectroscopy and UV spectrometry confirmed the authenticity of the substance. The racemic form of the substance Rim•HCl with an insignificant amount of impurity of the levorotatory enantiomer was proved polarimetrically: α =-0.0126±0.0003 (1% aqueous solution, 20±0.5 °С). The specific optical rotation of 1% aqueous solution H-His-Rim•2HCl•H2O . In 1% ethanol solution -10.32±0.12. Using the method of laser light diffraction for a substance H-His-Rim•2HCl•H2O, the dimensional spectra «fraction of particles, %-d, μm» were characterized, the maximum of which in hexane is in the region of 40–50 μm. Arrhenius’s kinetics on the Spirotox model established statistically significant differences in ligand-receptor interactions, which are characterized by values of observed apparent activation energy °bsEa, kJ/mol: 132.36±1.55 for H-His-Rim•2HCl•H2O and 176.15±0.48 for Rim•HCl. Conclusion: The developed set of methods for assessment of physical and chemical properties and biological activity of a new antiviral substance H-His-Rim•2HCl•H2O is the basis for establish of regulatory documentation

ASCORBIС ACID DEGRADATION IN N, N-DIMETHYLFORMAMIDE SOLUTIONS

Objective: Investigate the mechanisms of L-ascorbic acid transforтmation and formation of coloured enamines in N, N-dimethyl-formamide solutions. Methods: An automatic polarimeter Atago POL-1/2 was used for polarimetric investigation. Electronic spectra were recorded by UV-spectrometer Cary 60 (Agilent). The statistical analysis was carried out using the OriginPro 9.1 packages. Results: The Biot’s law violation was found in below 0.1% solutions of L-ascorbic acid (AA) in N, N-dimethylformamide (DMF). During the day, the specific rotation   of 1% AA solution varied from+37 to-1.0. Gradually, the solution acquired the red colour, and its intensity depended on the AA concentration. Spectrophotometrically, it was shown that after 15 min AA was absent in the n·10-3% solutions. The decomposition followed the first-order kinetics (k1=1.83·10-2с-1). At the same time, new absorption bands appeared at 273, 390, 533 nm. Model solutions containing dimethylamine (DMA) had a similar spectrum, and the intensity of the absorption bands increased in proportion to the concentration of DMA. Conclusion: The results show that the first step in the decomposition of ascorbic acid AA in DMF follows first-order kinetics. Numerous decomposition products are optically active compounds and reverse the sign of the optical rotation of the solution. The water resulting from the decomposition of AA is involved in the hydrolysis of the solvent. The hydrolysis product, the secondary amine DMA, interacts with the carbonyl groups of the AA decomposition products to form coloured enamines. Magnesium (II) accelerates the formation of coloured products

POLARIMETRIC RESEARCH OF PHARMACEUTICAL SUBSTANCES IN AQUEOUS SOLUTIONS WITH DIFFERENT WATER ISOTOPOLOGUES RATIO

Objective: Methodology development for quality control of optically active pharmaceutical substances based on water isotopologues. Methods: Solutions of L-ascorbic acid, glucose, galactose and valine stereoisomers were prepared using deuterium depleted water (DDW-«light» water, D/H=4 ppm), natural deionized high-ohmic water (BD, D/H=140 ppm), heavy water (99.9% D2O). The optical rotation was observed using an automatic polarimeter Atago POL-1/2. The size distribution of giant heterogeneous clusters (GHC) of water was recorded by low angle laser light scattering (LALLS) method. Results: The infringement of Biot's Law was found for solutions of ascorbic acid, expressed in the absence of a constant value of the specific optical rotation  at a concentration of below 0.1%, depends on the D/H ratio. The inequality was established in absolute values of optical rotation for L-and D-isomers of valine in solutions with different ratios of hydrogen isotopologues. The mutarotation of glucose confirmed the first-order kinetics, and the activation energies were statistically distinguishable for BD and DDW. The mutarotation of the natural galactose D-isomer proceeded with a lower energy consumption compared to the L-isomer. In heavy water, the mutarotation of monosaccharides had different kinetic mechanisms. Polarimetric results correlated with the number and size of GHC, which confirmed the possibility of chiral solvent structures induction by optically active pharmaceutical substances. Conclusion: In the optically active pharmaceutical substances quality control there should be considered the contribution of induced chiral GHC of water to the optical rotation value that depends on the isotopic D/H ratio, the substance nature and the form of its existence at a given pH

pH-чувствительные съедобные пленки на основе биокомпозита казеинат натрия/агар-агар

In the modern world, shelf life extension of foods with a possibility of controlling their freshness and quality in real time is gaining increasing importance. To solve this task, the development of pH-sensitive films based on edible biopolymers with addition of anthocyans as a color indicator can be proposed. For this experiment, sodium caseinate/ agar-agar biocomposite films with different content of anthocyans from black carrot (Scorconera hispanica) in a range of 0 to 15 mass% in increments of 5 mass% were prepared. It was established that the anthocyan content did not affect the thickness and moisture content of the films; however, it significantly reduced their moisture absorption and transparence. Water vapor permeability of the biocomposite films increased with an increase in the content of the aqueous extract of anthocyans from black carrot, which can be linked with the formation of pores and microcracks in the biocomposite matrix. All films with anthocyans showed changes in color depending on the environmental pH, which intensities depended on the anthocyan content. Edible films based on the mixture of sodium caseinate and agar-agar can potentially be used in the food industry to determine freshness of foods, which spoilage results in pH changes.В современном мире все большее значение приобретает продление срока годности продуктов питания с возможностью контроля их свежести и качества в режиме реального времени. Для решения этой задачи может быть предложена разработка рН-чувствительных пленок на основе съедобных биополимеров с добавкой антоцианов в качестве цветового индикатора. Для проведения данного исследования были приготовлены пленки биокомпозита казеинат натрия/агар-агар с различным содержанием антоцианов черной моркови (Scorconera hispanica) 0–15 масс.% с шагом 5 масс.%. Было установлено, что содержание антоцианов не влияет на толщину и влагосодержание пленок, однако значительно снижает их влагопоглощение и прозрачность. Паропроницаемость пленок биокомпозита возросла с увеличением содержания водного экстракта антоцианов черной моркови, что может быть связано с образованием пор и микротрещин в матрице биокомпозита. Все пленки с антоцианами показали изменение цвета в зависимости от рН среды, интенсивность которого зависела от содержания антоцианов. Съедобные пленки на основе смеси казеината натрия и агар-агара потенциально могут быть использованы в пищевой промышленности для определения свежести продуктов, в результате порчи которых происходит изменение рН

Evaluation of Artificial Intelligence Effectiveness in Detection of Lumbosacral Spine Degenerative Diseases

Objective: comparative evaluation of output data of a set of trained convolutional neural network (CNN) models and interpretation of pathological changes in lumbar spine by radiologists during magnetic resonance imaging.Material and methods. More than 12,000 anonymized archives were collected to generate training and test neural network datasets from patients aged over 18 years. Each archive consisted of a set of programs in two planes containing T2-TSE, T1-TSE and T2 sequences with fat suppression program. Subsequently, the selected studies were tagged in two steps, directly consisting of manual tagging and its validation by experts. CNN training was performed separately for normal analysis, qualitative detection of individual pathological changes, and quantitative analysis. The accuracy of the models was verified by comparing the protocols of five radiologists and the output of CNN models in two steps. The first, intermediate stage evaluated the accuracy of the neural networks in detecting disc bulges, protrusions and extrusions, spinal canal stenosis, lateral stenosis, foraminal stenosis, spondylolisthesis and facet joint arthrosis. In the final stage, in addition to the pathologies considered in the intermediate one, the accuracy of detecting degenerative changes of the occlusive plates, synovitis of intervertebral joints, intervertebral discs degeneration, osteophytes, transitional vertebrae, hypertrophy of yellow ligaments and Schmorl’s hernia was tested. The reference value for all pathological changes considered in this paper was determined by majority vote and, in case of disagreement, by an external radiologist. The radiologists’ interpretations were then compared with those of the trained model.Results. The artificial intelligence (AI) showed comparable sensitivity and specificity values compared to the reference result in a group of experienced radiologists for binary classification (presence/absence) of individual lumbosacral spine degenerative changes. The sensitivity and specificity of AI results were 0.88 and 0.97 for extrusions, 0.81 and 0.94 for protrusions, 0.87 and 0.98 for central stenosis, 0.83 and 0.85 for lateral stenosis, 0.92 and 0.84 for foraminal stenosis, 0.85 and 0.5 for osteoarthritis, 0.73 and 0.96 for occlusive plates degeneration, 0.85 and 0.84 for intervertebral joint synovitis, 0.91 and 0.88 for osteophytes, 0.93 and 0.72 for intervertebral disc degeneration, 1.0 and 1.0 for transitional vertebrae, 0.8 and 1.0 for spondylolisthesis, 0.67 and 0.99 for yellow ligament hypertrophy, and 0.75 and 1.0 for Schmorl’s hernia, respectively. The accuracy of quantitative size characterization of lumbosacral spine protrusions and extrusions showed unsatisfactory results, but improvements in the quality of determination of these parameters are planned in future work.Conclusion. AI models showed comparable performance to expert radiologists in detecting lumbosacral spine degenerative changes. Consistent improvement of CNN models based on comparative evaluation with radiologists improves the sensitivity and specificity of pathologic change detection

Awareness of cognitive decline trajectories in asymptomatic individuals at risk for AD

Background: Lack of awareness of cognitive decline (ACD) is common in late-stage Alzheimer’s disease (AD). Recent studies showed that ACD can also be reduced in the early stages. Methods: We described different trends of evolution of ACD over 3 years in a cohort of memory-complainers and their association to amyloid burden and brain metabolism. We studied the impact of ACD at baseline on cognitive scores’ evolution and the association between longitudinal changes in ACD and in cognitive score. Results: 76.8% of subjects constantly had an accurate ACD (reference class). 18.95% showed a steadily heightened ACD and were comparable to those with accurate ACD in terms of demographic characteristics and AD biomarkers. 4.25% constantly showed low ACD, had significantly higher amyloid burden than the reference class, and were mostly men. We found no overall effect of baseline ACD on cognitive scores’ evolution and no association between longitudinal changes in ACD and in cognitive scores. Conclusions: ACD begins to decrease during the preclinical phase in a group of individuals, who are of great interest and need to be further characterized. Trial registration: The present study was conducted as part of the INSIGHT-PreAD study. The identification number of INSIGHT-PreAD study (ID-RCB) is 2012-A01731-42

Low Cognitive Awareness, but Not Complaint, is a Good Marker of Preclinical Alzheimer's Disease

Subjective cognitive decline (SCD) may result from many conditions, including Alzheimer's disease (AD)