45 research outputs found

    Mixed forms of free oscillations of a rectangular CFCF-plate

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    Mixed (symmetrically/antisymmetric) forms of natural oscillations of a thin rectangular plate of constant thickness, in which two parallel sides are rigidly pinched, and the other two are free (CFCF plate, C — clamped, F — free), are studied. When all the conditions of the boundary value problem are satisfied, a resolving infinite homogeneous system of linear algebraic equations with respect to unknown coefficients of the series is obtained using two hyperbolotrigonometric series of the coordinate deflection function. Even functions on one coordinate and odd functions on another coordinate were used to obtain symmetric-antisymmetric waveforms. As a parameter, the resulting system contains the relative frequency of free oscillations. Nontrivial solutions of the reduced system were found by the method of successive approximations in combination with a search of the frequency parameter. Numerical results are obtained for the spectrum of the first six mixed (symmetric/antisymmetric — S-A and A-S) forms of free oscillations of a thin square CFCF plate of constant thickness. The natural frequencies were compared with the results of other authors and with known experimental values. The influence on the accuracy of the results of the number of members held in rows (the size of the reduced system) and the number of iterations is investigated. 3-D images of the found waveforms are presented. The results obtained can be used in the design of various sensors and sensors using the resonance phenomenon

    ОСОБЕННОСТИ ОНТОГЕНЕЗА СКЕЛЕТА ГОЛОВЫ САМЦОВ АМЕРИКАНСКОЙ НОРКИ ГЕНОТИПОВ STANDARD И LAVENDER (в норме и при воздействии препарата биостил)

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    The paper explores Biostil specimen on the American mink males of Standard and Lavender genotypes. The males selected were of different age from the experimental fur farm of theInstituteofCytologyand Genetics of Siberian Department ofRussianAcademyof Science. The paper is aimed at investigation of the influence on the growth and development of American mink males’ case brain skeleton of different genotypes aged 40–50; 86–90 and 176–180 days. The mink stock was bred by parents who were fed with Biostil dozed 0.05 ml/kg of body weight during 5 days before oestrum and during the oestrum. The authors observed the control animals who were not fed with Biostil. The mink stock was divided into the experimental and control groups according to the age and genotype features. The research was conducted by means of descriptive anatomic method and craniometric features. The authors found out 18 craniometric features. The research results show that Biostil influences positively morphogenesis of American mink males’ case brain of Standard genotype and some negative impact of Biostil on Lavender genotype. These impacts are mostly observed in the group of the males of reproductive age. Biostil impact on the morphogenesis of Lavender minks (a/a m/m) is followed by the changes in physiological parameters of growth and development of case brain that are mostly observed in the reproductive age. This impact is characterized by lower parameters of the case brain and lower growth of dorsal, ventral, cervical and sagittal crests.Проведены исследования препарата биостил на самцах американских норок генотипов Standard и Lavender разных возрастных групп на экспериментальной звероферме Института цитологии и генетики СО РАН. Целью работы являлось изучение влияния препарата биостил на рост и развитие скелета самцов американской норки разных окрасочных генотипов в возрасте 40–50; 86–90 и 176–180 дней на примере черепа. Поголовье норчат было получено от родительских пар, которым добавляли в корм биостил перед гоном в течение 5 дней и в период гона трёхкратно через день в дозе 0,05 мл/кг массы тела. Контролем служили животные, родители которых не получали с кормом биостил. Потомство было разделено на опытные и контрольные группы в соответствии с возрастными и генотипическими особенностями. Исследования проводили с помощью описательного анатомического метода и краниометрических измерений. Определено 18 краниометрических показателей. Результаты проведенных исследований позволяют сделать вывод о положительном влиянии препарата на морфогенез черепа самцов американской норки генотипа Standard и некотором угнетающем влиянии биостила на формирование черепа самцов американской норки генотипа Lavender. Указанные воздействия препарата наиболее выражены в группе самцов репродуктивного периода. Воздействие препарата на морфогенез черепа особей Lavender (a/a m/m) сопровождается изменением физиологических параметров роста и развития черепа, которые более четко проявляются в репродуктивном периоде и выражаются уменьшением размеров черепа, снижением активности роста дорсального, вентрального, затылочного и сагиттального гребней

    Анатомия и гистология тимуса американской норки генотипов Standard, Sapphire, Lavander в ранний постнатальный период онтогенеза

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    Data are presented on the thymus structure of American Mink of the Standard, Sapphire, Lavender colouring genotypes in the early postnatal period from birth to 180 days. The thymus is known to be a fully formed organ at birth. The anatomical structure of the thymus and its topography are not determined by genotype. At 45 days of age, the changes are manifested by an increase in the thymic lobule area and the brain matter therein, a decrease in the cortex area; the most intense growth of the thymus due to the rise in the number of lobules is noted. The thymus of mink at 45 to 90 days of age is characterised by an equalisation between the genotypes, increasing cortical area values to about the level of newborn mink with a corresponding increase in the cortical-brain index. The thymus of minks at the age of 90 to 180 days retains the typical morphological structure. Still, the signs of age involutive processes are seen – reduction of the lobule area, enlargement of the medulla, changes in the form of the organ (lobule fusion), increased signs of fat transformation thymus. Hassall’s corpuscles were found in the medulla in all periods of investigation. The number of Hassall’s bodies and their morphology depends on the functional activity of the thymus. In newborns, unicellular, young and juvenile forms predominate. In 45-day-old minks, young and immature forms predominate. In 90-day-old female and male Standard burros, young and quite often unicellular bodies are visualised, while mature and juvenile records are less common. In mink of the coloured genotypes, immature and youthful Hassall’s corpuscles are predominant. By 180 days, the number of mature and young corpuscles with signs of central cell destruction with detritus accumulation and cavity formation increases.Представлены данные по строению тимуса американских норок окрасочных генотипов Standard, Sapphire, Lavender в раннем постнатальном периоде от рождения до 180 дней. Установлено, что при рождении тимус является полностью сформированным органом. Анатомическое строение тимуса и его топография не определялись особенностями генотипа. Наибольшего значения весовые показатели тимуса достигали в 90 дней, минимального – в возрасте 180 дней. В 45 дней изменения проявляются увеличением площади тимической дольки и мозгового вещества в ней, уменьшением площади кортекса; отмечается наиболее интенсивный рост тимуса, обусловленный увеличением количества долек. Тимус норок в возрасте от 45 до 90 дней характеризуется выравниванием показателей между генотипами, происходит увеличение значений корковой зоны примерно до уровня новорожденных норчат с соответствующим увеличением корково-мозгового индекса. Тимус норок в возрасте от 90 до 180 дней сохраняет типичное морфологическое строение, но уже отчетливо просматриваются признаки возрастных инволютивных процессов – уменьшение площади долек, расширение мозгового вещества, изменение структуры органа (слияние долек), увеличение признаков жировой трансформации тимуса. Тельца Гассаля обнаруживались в мозговом веществе во все периоды исследования. Количество телец Гассаля и их морфология зависят от функциональной активности тимуса. У ново- рожденных преобладают одноклеточные, юные и молодые формы, у 45-дневных норок – юные и молодые, у 90-дневных самок и самцов норок Standard – юные тельца и достаточ- но часто визуализируются одноклеточные, в то время как зрелые и молодые встречаются реже. У норок цветных генотипов преобладающими являются молодые и юные тельца Гассаля. К возрасту 180 дней увеличивается количество зрелых телец и молодых с признаками разрушения центральной клетки с накоплением детрита и формированием полости

    FREQUENCIES OF POLYMORPHISMS IN THE CYTOCHROME’S P450 GENES OF WARFARIN TRANSFORMATION IN A EUROPEAN POPULATION OF EASTERN SIBERIA

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    Background. Genotypes of the cytochrome p450 isoform (CYP2C9 and CYP4F2) determine warfarin dose requirements. Frequencies of risk alleles and genotypes of CYP2C9 and CYP4F2 gene vary in different races and ethnic groups.Aim. This study analyzed the frequencies of *2, *3 alleles of CYP2C9 gene and the 1347 C>T allele of CYP4F2 gene in the Caucasians of Eastern Siberia, and compare with other populations.Materials and methods. Participants were 147 patients (Caucasians): 67 (45.58 %) man and 80 (54.42 %) women), taking warfarin for the prevention of thrombosis with a mean age of 64.74 ± 14.29 years. There were patients with atrial fibrillation – 77 (52.38 %) persons, coronary artery disease – 10 (6.80 %), pulmonary embolism – 5 (3.40 %), 15 (10.20 %) patients after implantation of an mechanical heart valve, etc. The subjects were genotyped for CYP2C9 (*1,*2,*3), and CYP4F2 (1347 C>T) by real-time polymerase chain reaction (RT-PCR) using “Pharmacogenetics Warfarin” reagent kits (DNA technology, Russia).Results. 69.4 % of Caucasians of Eastern Siberia (Russians), have two functional alleles (*1/*1) of CYP2C9 (they’re extensive/normal metabolizers), the number of intermediate metabolizers (*1/*2, *1/*3) was 29.8 % and 0.68 % of slow metabolizers (*3/*3). Homozygous carriers of two non-functional alleles *2 and *3 (*2/*2, *2/*3) were absent. Carriers of one coumarin-resistant Т-allele of CYP4F2 were 57 (38.7 %) respondents, two coumarin-resistant alleles – 10 (6.8 %) respondents.Conclusions. Frequencies of polymorphisms in the Cytochrome’s p450 genes of warfarin transformation in a European population of Eastern Siberia have no differences with other European populations of the worl

    Pharmacogenetic Warfarin Dosing Algorithm in the Russian Population

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    Background. To date, there are many pharmacogenetic algorithms for selecting the dose of warfarin. However, there is very little information about the predictive accuracy of the algorithms. We decided to evaluate the predictive accuracy of the Gage algorithm, using a calculator, located on the web site (http://www.warfarindosing.org) in two ethnic groups (Caucasians and Asians), living in Russia.Aim. To compare the actual warfarin dose (AWD) to the calculated warfarin dose (CWD), using the algorithm in two ethnic groups taking warfarin.Materials and methods. We included 114 patients (66 Caucasians and 48 Asians): the mean age was60.91 ± 12.34 years; 61 (53.51 %) men, and 53 (46.49 %) women. The comparative characteristics of the algorithm were tested using the mean absolute error (MAE) between AWD and CWD, and percentage of patients, whose CWD fell within 20 % of AWD (percentage within 20 %). Genotyping for CYP2C9*2, CYP2C9*3, CYP4F*2 and VKORC1 was performed by real-time polymerase chain reaction (RT-PCR) method using Pharmacogenetics Warfarin reagent kits (DNA technology, Russia).Results. The Gage algorithm produced the predictive accuracy with MAE = 1.02 ± 0.16 mg/day and percentage within 20 % for Asian patients was 39.6 %. We obtained MAE = 1.33 ± 0.16 mg/day and percentage within 20 % for Caucasian patients was 40.9 %. In two ethnic groups (Caucasians and Asians) of the Russian population, overall performance of warfarin pharmacogenetic dosing by the Gage algorithm was similar.Conclusions. Despite the performance limitation of the current warfarin pharmacogenetic dosing Gage algorithm, constant international normalized ratio monitoring is important

    Improved risk stratification of patients with atrial fibrillation: an integrated GARFIELD-AF tool for the prediction of mortality, stroke and bleed in patients with and without anticoagulation.

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    OBJECTIVES: To provide an accurate, web-based tool for stratifying patients with atrial fibrillation to facilitate decisions on the potential benefits/risks of anticoagulation, based on mortality, stroke and bleeding risks. DESIGN: The new tool was developed, using stepwise regression, for all and then applied to lower risk patients. C-statistics were compared with CHA2DS2-VASc using 30-fold cross-validation to control for overfitting. External validation was undertaken in an independent dataset, Outcome Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF). PARTICIPANTS: Data from 39 898 patients enrolled in the prospective GARFIELD-AF registry provided the basis for deriving and validating an integrated risk tool to predict stroke risk, mortality and bleeding risk. RESULTS: The discriminatory value of the GARFIELD-AF risk model was superior to CHA2DS2-VASc for patients with or without anticoagulation. C-statistics (95% CI) for all-cause mortality, ischaemic stroke/systemic embolism and haemorrhagic stroke/major bleeding (treated patients) were: 0.77 (0.76 to 0.78), 0.69 (0.67 to 0.71) and 0.66 (0.62 to 0.69), respectively, for the GARFIELD-AF risk models, and 0.66 (0.64-0.67), 0.64 (0.61-0.66) and 0.64 (0.61-0.68), respectively, for CHA2DS2-VASc (or HAS-BLED for bleeding). In very low to low risk patients (CHA2DS2-VASc 0 or 1 (men) and 1 or 2 (women)), the CHA2DS2-VASc and HAS-BLED (for bleeding) scores offered weak discriminatory value for mortality, stroke/systemic embolism and major bleeding. C-statistics for the GARFIELD-AF risk tool were 0.69 (0.64 to 0.75), 0.65 (0.56 to 0.73) and 0.60 (0.47 to 0.73) for each end point, respectively, versus 0.50 (0.45 to 0.55), 0.59 (0.50 to 0.67) and 0.55 (0.53 to 0.56) for CHA2DS2-VASc (or HAS-BLED for bleeding). Upon validation in the ORBIT-AF population, C-statistics showed that the GARFIELD-AF risk tool was effective for predicting 1-year all-cause mortality using the full and simplified model for all-cause mortality: C-statistics 0.75 (0.73 to 0.77) and 0.75 (0.73 to 0.77), respectively, and for predicting for any stroke or systemic embolism over 1 year, C-statistics 0.68 (0.62 to 0.74). CONCLUSIONS: Performance of the GARFIELD-AF risk tool was superior to CHA2DS2-VASc in predicting stroke and mortality and superior to HAS-BLED for bleeding, overall and in lower risk patients. The GARFIELD-AF tool has the potential for incorporation in routine electronic systems, and for the first time, permits simultaneous evaluation of ischaemic stroke, mortality and bleeding risks. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier for GARFIELD-AF (NCT01090362) and for ORBIT-AF (NCT01165710)

    Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

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    Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)

    Two-year outcomes of patients with newly diagnosed atrial fibrillation: results from GARFIELD-AF.

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    AIMS: The relationship between outcomes and time after diagnosis for patients with non-valvular atrial fibrillation (NVAF) is poorly defined, especially beyond the first year. METHODS AND RESULTS: GARFIELD-AF is an ongoing, global observational study of adults with newly diagnosed NVAF. Two-year outcomes of 17 162 patients prospectively enrolled in GARFIELD-AF were analysed in light of baseline characteristics, risk profiles for stroke/systemic embolism (SE), and antithrombotic therapy. The mean (standard deviation) age was 69.8 (11.4) years, 43.8% were women, and the mean CHA2DS2-VASc score was 3.3 (1.6); 60.8% of patients were prescribed anticoagulant therapy with/without antiplatelet (AP) therapy, 27.4% AP monotherapy, and 11.8% no antithrombotic therapy. At 2-year follow-up, all-cause mortality, stroke/SE, and major bleeding had occurred at a rate (95% confidence interval) of 3.83 (3.62; 4.05), 1.25 (1.13; 1.38), and 0.70 (0.62; 0.81) per 100 person-years, respectively. Rates for all three major events were highest during the first 4 months. Congestive heart failure, acute coronary syndromes, sudden/unwitnessed death, malignancy, respiratory failure, and infection/sepsis accounted for 65% of all known causes of death and strokes for <10%. Anticoagulant treatment was associated with a 35% lower risk of death. CONCLUSION: The most frequent of the three major outcome measures was death, whose most common causes are not known to be significantly influenced by anticoagulation. This suggests that a more comprehensive approach to the management of NVAF may be needed to improve outcome. This could include, in addition to anticoagulation, interventions targeting modifiable, cause-specific risk factors for death. CLINICAL TRIAL REGISTRATION: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

    Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

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    BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

    Distribution, feeding and growth of hatchery-reared Atlantic salmon (Salmo salar L.) parr stocked into rivers with various abiotic conditions

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    Within the research of efficiency of Atlantic salmon the artificial reproduction, feeding rate, distribution and growth of farm-raised one-year-old Atlantic salmon have been examined. The fish has been released into nursery areas with different hydrological characteristics located in the Rivers Kola, Umba, Srednyaya and Akkim in the Murmansk region. The observations have being conducted for 1–5 months since the moment of fish release. In natural habitat, juveniles rapidly distribute downstream and upstream regardless of water temperature, depth and current velocity. In all examined nursery areas adapting one-year-old juveniles prefer to stay at weak current sites close to the shore, hiding in the gravel. In all the cases farmed parr shows high feed rate, but qualitative composition of their food differs significantly from food composition of wild juveniles. Revealed peculiarities of adapting parr's distribution and qualitative food composition indicate the impact of long-term rearing at hatcheries on fish behavior. Growth rate of one-year-old juveniles is arcwise connected with fraction composition of gravel and the level of bottom fouling: the bigger bottom rocks are and the thicker the fouling is, the more intensive fish growth is. The revealed correlations have been described with equations of linear regression. Connections between juvenile growth and water temperature, current velocity and depth of the area have not been detected. The research outcomes could provide a basis for scientific advice for planning release sites and number of released one-year-old Atlantic salmon by hatcheries in the Murmansk region
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