Порівняння хроматографічних методів аналізу в тонкому шарі сорбенту при проведенні ідентифікації фамотидину у таблетках

Today three national manufacturers produce famotidine tablets, but the SPhU does not contain any monograph for this dosage form.Aim. To verify TLC and study the possibility of using the HPTLC method for identification of famotidine in tablets.Materials and methods. The objects of the study were three batches of famotidine tablets. TLC and HPTLC were used as the methods of the study.Results and discussion. The possibility of using TLC and HPTLC methods for identification of famotidine tablets was confirmed in the study. The main spots of the test solutions corresponded to the size and the Rf value of the main spots of the standard solution. The Rf value for all solutions was 0.5.Conclusions. Thus, TLC as well as HPTLC can be recommended for inclusion to the SPhU; however, HPTLC is more economically advantageous.Цель работы. На сегодняшний день три отечественных производителя выпускают таблетки фамотидина, однако несмотря на это, ГФУ не содержит  монографии на эту форму. Целью исследования было провести верификацию ТСХ и изучить возможность использования ВЭТСХ для идентификации фамотидина в таблетках.Материалы и методы. Объектами исследования были выбраны три серии таблеток фамотидина, методами исследования были выбраны ТСХ и ВЭТСХ.Результаты и их обсуждение. В ходе исследования была подтверждена возможность использования методик ТСХ и ВЭТСХ для идентификации фамотидина в таблетках. Основные пятна, полученные при хроматографировании испытуемых растворов, соответствуют размерам и положению основного пятна, полученного при хроматографировании раствора сравнения. Rf для всех растворов составил 0,5.Выводы. Таким образом, как ТСХ, так и ВЭТСХ могут быть рекомендованы для включения в ГФУ. Однако ВЭТСХ является более экономически выгодной.Мета роботи. На теперішній час три вітчизняних виробники випускають таблетки фамотидину, однак ДФУ не містить монографії на цю форму. Метою дослідження було провести верифікацію ТШХ та вивчити можливість застосування ВЕТШХ для ідентифікації фамотидину в таблетках. Матеріали та методи. Об’єктами дослідження було обрано три серії таблеток фамотидину. Методи дослідження – ТШХ та ВЕТШХ. Результати та їх обговорення. У ході дослідження було підтверджено можливість застосування методик ТШХ та ВЕТШХ для ідентифікації фамотидину у таблетках. Основні плями, отримані при хроматографуванні випробовуваних розчинів, відповідають за розмірами та положенням основній плямі, отриманій при хроматографуванні розчину порівняння. Rf для всіх розчинів становить 0,5. Висновки. Таким чином, як ТШХ, так і ВЕТШХ можуть бути рекомендовані для включення до ДФУ, однак ВЕТШХ є більш економічно вигідною.

Holographic analysis of diffraction structure factors

We combine the theory of inside-source/inside-detector x-ray fluorescence holography and Kossel lines/x ray standing waves in kinematic approximation to directly obtain the phases of the diffraction structure factors. The influence of Kossel lines and standing waves on holography is also discussed. We obtain partial phase determination from experimental data obtaining the sign of the real part of the structure factor for several reciprocal lattice vectors of a vanadium crystal.Comment: 4 pages, 3 figures, submitte

Surface reconstruction induced geometries of Si clusters

We discuss a generalization of the surface reconstruction arguments for the structure of intermediate size Si clusters, which leads to model geometries for the sizes 33, 39 (two isomers), 45 (two isomers), 49 (two isomers), 57 and 61 (two isomers). The common feature in all these models is a structure that closely resembles the most stable reconstruction of Si surfaces, surrounding a core of bulk-like tetrahedrally bonded atoms. We investigate the energetics and the electronic structure of these models through first-principles density functional theory calculations. These models may be useful in understanding experimental results on the reactivity of Si clusters and their shape as inferred from mobility measurements.Comment: 9 figures (available from the author upon request) Submitted to Phys. Rev.

Near Resonant Spatial Images of Confined Bose-Einstein Condensates in the '4D' Magnetic Bottle

We present quantitative measurements of the spatial density profile of Bose-Einstein condensates of sodium atoms confined in a new '4D' magnetic bottle. The condensates are imaged in transmission with near resonant laser light. We demonstrate that the Thomas-Fermi surface of a condensate can be determined to better than 1%. More generally, we obtain excellent agreement with mean-field theory. We conclude that precision measurements of atomic scattering lengths and interactions between phase separated cold atoms in a harmonic trap can be measured with high precision using this method.Comment: 15 pages, 3 figures. Submitted 10/30/97, accepted for publication in Phys. Rev. A Rapid Com

Shape Transition in the Epitaxial Growth of Gold Silicide in Au Thin Films on Si(111)

Growth of epitaxial gold silicide islands on bromine-passivated Si(111) substrates has been studied by optical and electron microscopy, electron probe micro analysis and helium ion backscattering. The islands grow in the shape of equilateral triangles up to a critical size beyond which the symmetry of the structure is broken, resulting in a shape transition from triangle to trapezoid. The island edges are aligned along $Si[110]$ directions. We have observed elongated islands with aspect ratios as large as 8:1. These islands, instead of growing along three equivalent [110] directions on the Si(111) substrate, grow only along one preferential direction. This has been attributed to the vicinality of the substrate surface.Comment: revtex version 3.0, 11 pages 4 figures available on request from [email protected] - IP/BBSR/93-6

Изучение видового состава микробиома фитофагов цветочных растений на основании данных ДНК-штрихкодирования

Based on the DNA-barcoding data, a molecular-genetic identification of the dominant microbiome species composition of the perennial floral plants phytophages was carried out. Various variants of species combinations in the microbiota–phytophagous system, as well as the ways of phytophagous transmission of pathogenic microflora have been identified.С использованием метода баркодирования ДНК проведена молекулярно-генетическая идентификация доминирующего видового состава микробиома фитофагов многолетних цветочных растений. Выявлены различные варианты видовых сочетаний в системе «микробиота–фитофаг», а также изучены способы переноса фитофагами патогенной микрофлоры

Effect of SGLT2 inhibitors on stroke and atrial fibrillation in diabetic kidney disease: Results from the CREDENCE trial and meta-analysis

BACKGROUND AND PURPOSE: Chronic kidney disease with reduced estimated glomerular filtration rate or elevated albuminuria increases risk for ischemic and hemorrhagic stroke. This study assessed the effects of sodium glucose cotransporter 2 inhibitors (SGLT2i) on stroke and atrial fibrillation/flutter (AF/AFL) from CREDENCE (Canagliflozin and Renal Events in Diabetes With Established Nephropathy Clinical Evaluation) and a meta-Analysis of large cardiovascular outcome trials (CVOTs) of SGLT2i in type 2 diabetes mellitus. METHODS: CREDENCE randomized 4401 participants with type 2 diabetes mellitus and chronic kidney disease to canagliflozin or placebo. Post hoc, we estimated effects on fatal or nonfatal stroke, stroke subtypes, and intermediate markers of stroke risk including AF/AFL. Stroke and AF/AFL data from 3 other completed large CVOTs and CREDENCE were pooled using random-effects meta-Analysis. RESULTS: In CREDENCE, 142 participants experienced a stroke during follow-up (10.9/1000 patient-years with canagliflozin, 14.2/1000 patient-years with placebo; hazard ratio [HR], 0.77 [95% CI, 0.55-1.08]). Effects by stroke subtypes were: ischemic (HR, 0.88 [95% CI, 0.61-1.28]; n=111), hemorrhagic (HR, 0.50 [95% CI, 0.19-1.32]; n=18), and undetermined (HR, 0.54 [95% CI, 0.20-1.46]; n=17). There was no clear effect on AF/AFL (HR, 0.76 [95% CI, 0.53-1.10]; n=115). The overall effects in the 4 CVOTs combined were: Total stroke (HRpooled, 0.96 [95% CI, 0.82-1.12]), ischemic stroke (HRpooled, 1.01 [95% CI, 0.89-1.14]), hemorrhagic stroke (HRpooled, 0.50 [95% CI, 0.30-0.83]), undetermined stroke (HRpooled, 0.86 [95% CI, 0.49-1.51]), and AF/AFL (HRpooled, 0.81 [95% CI, 0.71-0.93]). There was evidence that SGLT2i effects on total stroke varied by baseline estimated glomerular filtration rate (P=0.01), with protection in the lowest estimated glomerular filtration rate (45 mL/min/1.73 m2]) subgroup (HRpooled, 0.50 [95% CI, 0.31-0.79]). CONCLUSIONS: Although we found no clear effect of SGLT2i on total stroke in CREDENCE or across trials combined, there was some evidence of benefit in preventing hemorrhagic stroke and AF/AFL, as well as total stroke for those with lowest estimated glomerular filtration rate. Future research should focus on confirming these data and exploring potential mechanisms