Electrocatalytic determination of oxalate ions on chemically modified electrodes

The electrocatalytic activity with respect to oxalate ions of spongy osmium immobilized within a carbon-paste electrode was studied. A procedure is proposed for electrocatalytic determination of oxalate ions on a chemically modified electrode based on spongy osmium under conditions of flow-through-injection analysis. © 2001 MAIK "Nauka/Interperiodica"

New approaches to registration and conservation of domestic cultivars of berry crops in the VIR Genebank on the example of red raspberry and black currant

A collection of nomenclatural standards is being created at VIR for domestic cultivars of various crops in accordance with the International Code of Nomenclature for Cultivated Plants (ICNCP). A new complex strategy was proposed for vegetatively propagated crops for registering domestic cultivars received from their authors in the VIR genebank. In addition to the creation of nomenclature standards, the strategy includes the development of a genetic passport of a cultivar and the use of biotechnological methods to preserve explants (buds, meristems) isolated from plant material transferred by breeders to the VIR Herbarium. This approach can be used for any vegetatively propagated crop applying a protocol developed specifically for an individual crop. For raspberry and black currant varieties, the collecting of plant material, its preparation for the registration of nomenclature standards and the preservation of viable samples under controlled in vitro conditions have specific features. This article provides detailed protocols for performing the mentioned work for raspberry and black currant varieties. In addition, the article summarizes the first results of the implementation of our proposed strategy on the example of domestic raspberry and black currant varieties created in various breeding centers of Russia. Three years of joint work of VIR researchers and breeders from four breeding centers in five regions of the country have resulted in creation of nomenclature standards for 20 raspberry varieties, as well as for five black currant varieties bred at VIR. Thirteen samples of raspberry varieties and four of black currant varieties, genetically identical to nomenclature standards, were introduced into in vitro culture; four raspberry cultivars have been placed in the VIR cryobank for the long-term cryopreservation

DEGREE ASSESSMENT OF POLLUTION AND PATHOLOGY OF UPPER RESPIRATORY TRACT IN TEENAGERS OF URBANIZED TERRITORIES OF IRKUTSK REGION

This study aimed to reveal air pollution and its influence on pathology of upper respiratory tract in teenagers of Angarsk and Sayansk. The quantitative content of chemical substances in the atmospheric air of the celitebic territory of Angarsk and Sayansk was studied based on the data of the hydro-meteorological center, the content of chemical substances in indoor air was assessed based on studying of the educational institutions. Two territories with a different pollution level were chosen to investigate in Angarsk. The higher summary risk of forming the respiratory organ pathology stipulated by the indoor air pollution and the atmospheric air with the tropic substances to the systems indicated was revealed to be in the schoolchildren in Angarsk. The studies performed in the educational school rooms have shown that on the whole the largest pollution degree was induced by the suspended substances. In the educational school rooms studied in Angarsk the increase in the hygienic normative on suspended substances was found to be in the educational classes in 43 % of samples, in the computer classes and in the sporting halls - in 44 % of samples. Sometimes the increase in the limited allowed concentration (LAC) was more than 2 times. The increase in the LAC of formaldehyde was observed to be in 13 % of samples in the educational classes. In the incidence structure according to applying for medical assistance the respiratory organ diseases were found to occupy the first place, at the same time the pathology of the upper respiratory ways prevailed in both towns. The chronic glandular and adenoid diseases as well as the allergic rhinitis were more often revealed. In comparison of the regions in Angarsk which are different in the pollution levels, it was found that the chronic pathology of the upper respiratory ways occurred 1,4 times more often in first region than in second one and 2,8 times more often than in Sayansk

Properties of Neutral Charmed Mesons in Proton--Nucleus Interactions at 70 GeV

The results of treatment of data obtained in the SERP-E-184experiment "Investigation of mechanisms of the production of charmed particles in proton-nucleus interactions at 70 GeV and their decays" by irradiating the active target of the SVD-2 facility consisting of carbon, silicon, and lead plates, are presented. After separating a signal from the two-particle decay of neutral charmed mesons and estimating the cross section for charm production at a threshold energy {\sigma}(c\v{c})=7.1 \pm 2.4(stat.) \pm 1.4(syst.) \mub/nucleon, some properties of D mesons are investigated. These include the dependence of the cross section on the target mass number (its A dependence); the behavior of the differential cross sections d{\sigma}/dpt2 and d{\sigma}/dxF; and the dependence of the parameter {\alpha} on the kinematical variables xF, pt2, and plab. The experimental results in question are compared with predictions obtained on the basis of the FRITIOF7.02 code.Comment: 9 pages, 9 figures,3 table

Определение сакситоксина в воде озера Байкал

Выполнено определение сакситоксина в пробах поверхностной воды, отобранной летом 2018 года в период массового цветения цианобактерий в прибрежной зоне заливов Ая, Тутай (западное побережье Байкала), Мухор (пролив Малое Море), Посольский сор и около села Турка (восточное побережье Байкала). Для определения сакситоксина использована методика определения, основанная на химической модификации сакситоксина 2,4-динитрофенилгидразином с последующей идентификацией гидразона сакситоксина методом жидкостной хроматографии с масс-спектрометрическим детектированием. Для проб с ожидаемой низкой концентрацией сакситоксина предложен усовершенствованный вариант методики. Показано, что содержание сакситоксина в воде во всех исследованных пробах ниже рекомендованной для питьевой воды (< 3 мкг/л)

Observation of narrow baryon resonance decaying into pKs0pK^0_s in pA-interactions at 70GeV/c70 GeV/c with SVD-2 setup

SVD-2 experiment data have been analyzed to search for an exotic baryon state, the $\Theta^+$-baryon, in a $pK^0_s$ decay mode at $70 GeV/c$ on IHEP accelerator. The reaction $pA \to pK^0_s+X$ with a limited multiplicity was used in the analysis. The $pK^0_s$ invariant mass spectrum shows a resonant structure with $M=1526\pm3(stat.)\pm 3(syst.) MeV/c^2$ and $\Gamma < 24 MeV/c^2$. The statistical significance of this peak was estimated to be of $5.6 \sigma$. The mass and width of the resonance is compatible with the recently reported $\Theta^+$- baryon with positive strangeness which was predicted as an exotic pentaquark ($uudd\bar{s}$) baryon state. The total cross section for $\Theta^+$ production in pN-interactions for $X_F\ge 0$ was estimated to be $(30\div120) \mu b$ and no essential deviation from A-dependence for inelastic events $(\sim A^{0.7})$ was found.Comment: 8 pages, 7 figures, To be submitted to Yadernaya Fizika. v3-v5 - Some references added, minor typos correcte

Текстурные и КТ-признаки в дифференциальном диагнозе гиперваскулярных нейроэндокринных опухолей поджелудочной железы и метастазов почечно-клеточного рака: диагностическая модель

Objective: to develop a diagnostic model that includes CT and radiomic features for the differential diagnosis of pancreatic neuroendocrine tumors (PNETs) G1 and G2 and pancreatic renal cell carcinoma (RCC) metastases.Material and Methods. 78 patients with 79 hypervascular PNETs and 17 patients with 24 pancreatic RCC metastases who underwent pancreatic resection and histological verification were selected in the study. All the patients underwent preoperative contrast enhanced CT (CECT). We assessed tumor attenuation, composition (cystic/solid), homogeneity (homogeneous/heterogeneous), calcification and presence of the main pancreatic duct (MPD) dilation. We calculated lesion-to-parenchyma contrast (LPC), relative tumor enhancement ratio (RTE) and extracted 52 texture features for arterial phase of CECT. Qualitative and texture features were compared between PNETs and pancreatic RCC metastasis. The selection of predictors for the logistic model was carried out in 2 successive stages: 1) selection of predictors based on one-factor logistic models, the selection criterion was p &lt; 0.2; 2) selection of predictors using L2 regularization (LASSO regression after standardization of independent variables). The selected predictors were included in a logistic regression model without interactions, the coefficients of which were estimated using the maximum likelihood method with a penalty of 0.8.Results. There was no difference in composition, homogeneity (homogeneous/heterogeneous) and presence of the MPD dilation between groups. We did not find calcification in pancreatic RCC metastasis, in contrast to the PNETs (9% contained calcifications). After selection, the LCR, CONVENTIONAL_HUmin, GLCM_Correlation, NGLDM_Coarseness were included in the final diagnostic model, which showed a sensitivity and specificity of 95.8%; 62% in the prediction of pancreatic RCC metastases.Conclusion. The diagnostic model developed on the basis of texture and CT-features has high sensitivity (95.8%) with moderate specificity (62%), which allows it to be used in complex diagnostic cases to determine the patient's treatment tactics.Цель исследования: разработать диагностическую модель, включающую КТ-характеристики и показатели радиомики для дифференциальной диагностики нейроэндокринных опухолей поджелудочной железы (ПНЭО) G1 и G2 и метастазов почечно-клеточного рака (ПКР).Материал и методы. В исследование были отобраны 78 пациентов с 79 гиперваскулярными ПНЭО и 17 пациентов с 24 метастазами ПКР, которым была выполнена резекция поджелудочной железы с гистологической верификацией. Всем пациентам перед операцией была проведена КТ с контрастным усилением. Мы оценивали плотность опухоли, структуру (кистозная/солидная), гомогенность (гомогенная/гетерогенная), кальцификацию и наличие расширения главного протока поджелудочной железы (ГПП). Мы рассчитали отношение плотности опухоли к плотности паренхимы (LPC) и относительный коэффициент контрастирования опухоли (RTE) и вычислили 52 текстурных показателя для артериальной фазы КТ-исследования. Качественные и текстурные характеристики сравнивали между ПНЭО и метастазами ПКР. Отбор предикторов в логистическую модели осуществлялся в 2 последовательных этапа: 1) отбор предикторов на основе однофакторных логистических моделей, критерием отбора служило p &lt; 0.2; 2) отбор предикторов с помощью L2-регуляризации (LASSO-регрессия после стандартизации независимых переменных). Отобранные предикторы включались в логистическую регрессионную модель без взаимодействий, коэффициенты которой рассчитывались с использованием метода максимального праводоподобия со штрафом 0,8.Результаты. Не было различий в структуре, гомогенности (гомогенные/гетерогенные) и наличии дилатации ГПП между группами. Мы не обнаружили кальцификации при метастазах ПКР, в отличие от ПНЭО. После отбора LCR, CONVENTIONAL_HUmin, GLCM_Correlation, NGLDM_Coarseness были включены в окончательную диагностическую модель, которая показала чувствительность и специфичность 95.8%; 62% в прогнозировании метастазов ПКР.Заключение. Разработанная на основании текстурных и КТ-признаков диагностическая модель обладает высокой чувствительностью (95.8%) при умеренной специфичности (62%), что позволяет использовать ее при сложных диагностических случаях для определения тактики лечения пациента

Дифференциальная диагностика псевдотуморозного панкреатита и протоковой аденокарциномы поджелудочной железы: характеристики КТ с контрастированием и текстурного анализа

Purpose. Improving the efficiency of CT in the differential diagnosis of mass-forming pancreatitis (MFP) and pancreatic ductal adenocarcinoma (PDAC) making a diagnostic model based using a combination of texture features and contrast enhancement features.Methods and materials. 45 patients with histologically confirmed non-metastatic locally advanced PDAC and 13 patients with MFP where underwent CT examination with contrast enhancement. For each group, the ratio of the densities of intact pancreatic tissue and tumors, the relative tumor enhancement ratio (RTE) in all enhanced phases of CT, 94 texture features for each phase of the study were calculated and compared. The selection of predictors in the logistic model was carried out in 2 stages: 1) selection of predictors based on one-factor logistic models, the selection criterion was padj &lt;0.2; 2) selection of predictors using LASSO-regression after standardization of variables. The selected predictors were included in a logistic regression model without interactions.Results. There were statistically significant differences in 14, 17, 4 out of 94 for the unenhanced, arterial, and venous phases of the study, respectively (p &lt; 0.05). After selection, the final diagnostic model included the texture features CONVENTIONAL HUQ2 and DISCRETIZED HUQ1 for the unenhanced phase, DISCRETIZED HUQ1 and GLRLM RLNU for the arterial phase, DISCRETIZED Skewness for the venous phase, RTE for the delayed CT phase. The diagnostic model was built showed an accuracy of 81% in the diagnosis of MFP.Conclusion. We have developed a diagnostic model, including textural parameters and contrast enhancement features, which allows preoperatively distinguish MFP and PDAC, the developed model will increase the accuracy of preoperative diagnosis.Цель исследования: повышение эффективности КТ в дифференциальной диагностике протоковой аденокарциномы поджелудочной железы (ПАК ПЖ) и псевдотуморозного хронического панкреатита (ПХП); составление диагностической модели на основе извлеченных текстурных показателей в комбинации с характеристиками контрастирования.Материал и методы. В исследование было включено 45 пациентов с гистологически подтвержденной неметастатической местнораспространенной ПАК ПЖ и 13 пациентов с ПХП, которым было выполнено КТ-исследование с внутривенным контрастированием. Для каждой группы рассчитаны отношение плотностей сохранной ткани поджелудочной железы и образований, относительный коэффициент накопления образований (RTE) во все контрастные фазы КТ-сканирования, 94 текстурных показателя для каждой фазы исследования и проведено их сравнение. Отбор предикторов в логистическую модель осуществлялся в 2 этапа: 1) отбор предикторов на основе однофакторных логистических моделей, критерием отбора служило padj &lt; 0,2; 2) отбор предикторов с помощью “лассо”-регрессии после стандартизации переменных. Отобранные предикторы включались в логистическую регрессионную модель без взаимодействий.Результаты. Статистически значимо различались 14, 17, 4 из 94 для нативной, артериальной, венозной фаз исследования соответственно (p &lt; 0,05). После отбора в итоговую диагностическую модель были включены показатели CONVENTIONAL HUQ2 и DISCRETIZED HUQ1 для нативной фазы, DISCRETIZED HUQ1 и GLRLM RLNU для артериальной фазы, DISCRETIZED Skewness для венозной фазы, RTE для отсроченной фазы КТ-исследования. На их основании построена диагностическая модель, показавшая точность 81% в диагностике ПХП.Заключение. Разработанная нами диагностическая модель, включающая текстурные показатели и характеристики контрастирования, позволяет предоперационно отличать ПХП и ПАК ПЖ и повысить точность предоперационной диагностики