Self-energy limited ion transport in sub-nanometer channels

The current-voltage characteristics of the alpha-Hemolysin protein pore during the passage of single-stranded DNA under varying ionic strength, C, are studied experimentally. We observe strong blockage of the current, weak super-linear growth of the current as a function of voltage, and a minimum of the current as a function of C. These observations are interpreted as the result of the ion electrostatic self-energy barrier originating from the large difference in the dielectric constants of water and the lipid bilayer. The dependence of DNA capture rate on C also agrees with our model.Comment: more experimental material is added. 4 pages, 7 figure

Stability of the liquid particles separation in the apparatus of oil and gas systems

The article considers the methods of associated gas purification from liquid particles. The sintering of liquid particles occurs during the separation process and the trapped droplets can be removed as a liquid stream, i.e. there is no need for unloading units. The droplet size depends on the energy input during their fragmentation. The efficiency of drops separation depends on the flow rate and the intensification of droplets coalescence, film formation and liquid flow to the receiver. The dispersion of the liquid particles is the main drawback of the existing purification methods, i.e. lack of sustainability of particle separation. The comparison of the separation system methods and the devices with flow control elements is carried out. The estimation of gas purification efficiency is conducted. It is concluded that the efficiency of associated gas purification gives the possibility to use it in turbine generators, heating furnaces, etc. It significantly reduces the proportion of gas being flared

КЛАССИФИКАЦИЯ ДЕФЕКТОВ ФАРМАКОТЕРАПИИ КАК ОСНОВА ОЦЕНКИ КАЧЕСТВА ЛЕКАРСТВЕННОЙ ТЕРАПИИ ПРИ ОКАЗАНИИ МЕДИЦИНСКОЙ ПОМОЩИ

Optimization of pharmacotherapy, as improving the quality of care is an important goal of modern medicine. The solution to this problem can be realized with the development and adoption of clear formal criteria. Using aprocess-based approach, we have developed a method for detecting defects in pharmacotherapy. We have analyzed the prospects of using this approach to research the quality of pharmacotherapy in health care and the formation of national programs to improve the quality of care.Оптимизация фармакотерапии, как и повышение качества медицинской помощи, является важной задачей современной медицины. Решение этой проблемы может быть реализовано с помощью разработки и принятия четких формализованных критериев. На основе процессного подхода разработана схема выявления дефектов фармакотерапии. Проведен анализ перспективности использования данного подхода для проведения целенаправленных исследований качества фармакотерапии в учреждениях здравоохранения и формирования отечественных программ улучшения качества оказания медицинской помощи

On Conduction in a Bacterial Sodium Channel

Voltage-gated Na+-channels are transmembrane proteins that are responsible for the fast depolarizing phase of the action potential in nerve and muscular cells. Selective permeability of Na+ over Ca2+ or K+ ions is essential for the biological function of Na+-channels. After the emergence of the first high-resolution structure of a Na+-channel, an anionic coordination site was proposed to confer Na+ selectivity through partial dehydration of Na+ via its direct interaction with conserved glutamate side chains. By combining molecular dynamics simulations and free-energy calculations, a low-energy permeation pathway for Na+ ion translocation through the selectivity filter of the recently determined crystal structure of a prokaryotic sodium channel from Arcobacter butzleri is characterised. The picture that emerges is that of a pore preferentially occupied by two ions, which can switch between different configurations by crossing low free-energy barriers. In contrast to K+-channels, the movements of the ions appear to be weakly coupled in Na+-channels. When the free-energy maps for Na+ and K+ ions are compared, a selective site is characterised in the narrowest region of the filter, where a hydrated Na+ ion, and not a hydrated K+ ion, is energetically stable

Оптимизация способа получения богатой тромбоцитами плазмы для использования в клинической практике

INTRODUCTION Development of effective biological products, based on human platelets, is very actual in regenerative medicine. The initial material for biological products’ obtaining is platelet-rich plasma (PRP), but the method of PRP isolation has not yet been standardized.AIM To assess the quality of platelets in PRP, harvested by different centrifugation modes.MATERIAL AND METHODS For platelet study, venous blood was harvested from volunteer donors. We used 3 methods for PRP-preparation, each methods included 2-stage centrifugation: 5 min 300g and 17 min 700g (Group 1); 10 min 300g and 10 min 700g (Group 2); 15 min 300g and 5 min 700g (Group 3). Platelets were examined using morphofunctional method based on vital cell staining.RESULTS In Group 1 and Group 2, the overall safety of biologically high-grade platelets in PRP was similar and estimated 55-60% of their total content in the blood. In Group 3 the safety of biologically high-grade platelets was only 30% (p<0,05).CONCLUSION The centrifugation modes «5 min 300 g / 700 g 17 min» and «10 min 300 g / 10 min 700 g» allowed researchers to obtain equal quality PRP, while «10 min 300 g / 10 min 700 g» mode has a number of instrumental benefits.АКТУАЛЬНОСТЬ В настоящее время идет активный поиск и разработка эффективных биопрепаратов на основе тромбоцитов человека, предназначенных для использования в регенеративной медицине. Исходным материалом для получения биопрепаратов является богатая тромбоцитами плазма (БоТП), при этом методика выделения БоТП до сих пор не стандартизирована.ЦЕЛЬ ИССЛЕДОВАНИЯ Оценить качество тромбоцитов в БоТП, выделенной при разных режимах центрифугирования.МАТЕРИАЛ И МЕТОДЫ В качестве источника тромбоцитов использовали кровь доноров-добровольцев. Для выделения БоТП использовали три методики, каждая из методик включала 2-этапное центрифугирование: в течение 5 мин с ускорением 300 g и 17 мин с ускорением 700 g (1-я группа); в течение 10 мин с ускорением 300 g и 10 мин с ускорением 700 g (2-я группа); в течение 15 мин с ускорением 300 g и 5 мин с ускорением 700 g (3-я группа). Тромбоциты исследовали с помощью способа оценки морфофункционального статуса тромбоцитов, основанного на витальном окрашивании клеток.РЕЗУЛЬТАТЫ Было показано, что в образцах БоТП 1-й и 2-й групп общая сохранность биологически полноценных тромбоцитов была сходной и составляла 55–60% от их общего содержания в крови. В 3-й группе сохранность биологически полноценных тромбоцитов составила лишь 30% (р<0,05, статистически значимо).ВЫВОДЫ Режимы центрифугирования в течение 5 мин с ускорением 300 g / 17 мин с ускорением 700 g и 10 мин с ускорением 300 g / 10 мин с ускорением 700 g позволяют получить БоТП равного качества; вместе с тем режим центрифугирования в течение 10 мин 300 g / 10 мин 700 g имеет ряд инструментальных преимуществ

Cancer Biomarker Discovery: The Entropic Hallmark

Background: It is a commonly accepted belief that cancer cells modify their transcriptional state during the progression of the disease. We propose that the progression of cancer cells towards malignant phenotypes can be efficiently tracked using high-throughput technologies that follow the gradual changes observed in the gene expression profiles by employing Shannon's mathematical theory of communication. Methods based on Information Theory can then quantify the divergence of cancer cells' transcriptional profiles from those of normally appearing cells of the originating tissues. The relevance of the proposed methods can be evaluated using microarray datasets available in the public domain but the method is in principle applicable to other high-throughput methods. Methodology/Principal Findings: Using melanoma and prostate cancer datasets we illustrate how it is possible to employ Shannon Entropy and the Jensen-Shannon divergence to trace the transcriptional changes progression of the disease. We establish how the variations of these two measures correlate with established biomarkers of cancer progression. The Information Theory measures allow us to identify novel biomarkers for both progressive and relatively more sudden transcriptional changes leading to malignant phenotypes. At the same time, the methodology was able to validate a large number of genes and processes that seem to be implicated in the progression of melanoma and prostate cancer. Conclusions/Significance: We thus present a quantitative guiding rule, a new unifying hallmark of cancer: the cancer cell's transcriptome changes lead to measurable observed transitions of Normalized Shannon Entropy values (as measured by high-throughput technologies). At the same time, tumor cells increment their divergence from the normal tissue profile increasing their disorder via creation of states that we might not directly measure. This unifying hallmark allows, via the the Jensen-Shannon divergence, to identify the arrow of time of the processes from the gene expression profiles, and helps to map the phenotypical and molecular hallmarks of specific cancer subtypes. The deep mathematical basis of the approach allows us to suggest that this principle is, hopefully, of general applicability for other diseases

CLASSIFICATION OF DEFECTS PHARMACOTHERAPY AS THE BASIS OF QUALITY ASSESSMENT OF DRUG THERAPY IN HEALTHCARE

Optimization of pharmacotherapy, as improving the quality of care is an important goal of modern medicine. The solution to this problem can be realized with the development and adoption of clear formal criteria. Using aprocess-based approach, we have developed a method for detecting defects in pharmacotherapy. We have analyzed the prospects of using this approach to research the quality of pharmacotherapy in health care and the formation of national programs to improve the quality of care

MEDICAL SCIENCES ВЛИЯНИЕ СОЦИАЛЬНЫХ ФАКТОРОВ НА СМЕРТНОСТЬ НАСЕЛЕНИЯ INFLUENCE OF SOCIAL FACTORS ON POPULATION MORTALITY

Переход РФ к рыночной экономике в 1991 году сопровождался повышением смертности и снижением рождаемости, что привело к отрицательному приросту населения. Механизмы этого явления до конца не изучены. Настоящее исследование было проведено с целью анализа динамики смертности населения и вли-яния на нее социальных факторов за 1992-2012 годы. Демографические данные и показатели социального благополучия населения получены при анализе общедоступных баз данных. Было выявлено, что показатель денежных доходов населения, доля доходов от оплаты труда, индекс Джини не коррелировали с показателем общей смертности населения. Динамику, сходную с изменением общей смертности населения, имел пока-затель доли населения с доходами ниже прожиточного минимума, который коррелирует с уровнем бедности в стране. Построенные нами регрессионные модели зависимости смертности населения от доли населения ниже прожиточного минимума были достоверными, и их анализ позволил констатировать, что снижение доли населения ниже прожиточного минимума на 1 % соответствует снижению смертности населения от всех причин на 20-25 человек на 100 тысяч населения. В 2013 году вклад фактора бедности в смертность населения составил 30 %. Структурный анализ показал, что изменение смертности от сердечно-сосудистых заболеваний и внешних причин соответствовало изменению доли населения с доходами ниже прожиточного минимума, тогда как для новообразований такой закономерности не регистрировалось. Проведенное нами исследование свидетельствует о роли социальных факторов в смертности и необходимости их учета при разработке государственных и региональных программ социального развития. Следует подчеркнуть, что для снижения смертности населения необходимо улучшение уровня жизни, использование мер поддержки социально неблагополучных слоёв общества. Ключевые слова: демография, социальные факторы, смертность населения INFLUENCE OF SOCIAL FACTORS ON POPULATION MORTALITY Burykin I.M., Khafi syanova R.K. Department of pharmacology, Kazan State Medical University, Kazan, e-mail: [email protected] Transfer Russian Federation to the new economic system in 1991 raised mortality and decreased birth rate. As a result, from 1992 to 2012 growth population of Russia Federation was negative. The mechanism of this phenomenon do not clearly understood. This Investigation analyzed patterns of death rate changes for the period 1992-2012 years, the role of social factors in this process, correlation mortality rate and standard of living, poverty level. A retrospective study was based on data from national and WHO database. This research did not show correlation between mortality rate and money income of the country's population, the share of income from wage. Graphic analysis revealed identical patterns of changes population mortality and the share of the population with incomes below the subsistence minimum. We produce a regression model for the period 1995-2001 и 2002-2013 years. Mathematical model shows that 1 % decrease the percentage of the population with incomes under the subsistence minimum correspond with decrease population mortality to 20-25 person on 100000 populations. In 2013 this social factor accounts for 30 % deaths in the Russian Federation. This survey discovered that the percentage of the population with incomes under the subsistence minimum correlated with cardiovascular mortality and deaths from external campaigns. No correlation found in mortality from neoplasms. This study demonstrated the role of social factor and poverty in population mortality. This factor must be considered in governments programs