Morphology of Camellia Sinensis L. leaves as marker of white tea authenticity

Received: February 1st, 2021 ; Accepted: April 24th, 2021 ; Published: August 18th, 2021 ; Correspondence: [email protected] is one of the most common drinks in the world. Classic tea is obtained by brewing the leaves of the Camellia sinensis L plant in hot water. However, even the leaves collected from the same branch of the same tea bush can have completely different anatomical, biochemical and taste characteristics. White tea is the youngest, immature apical leaves of the tea bush (fleshes) together with leaf buds (tips) which are is considered the most valuable parts of teaplant. The chemical composition of tea is studied in sufficient detail, however, there are still no uniform criteria for determining the authenticity of white tea leaves, which creates great preconditions for falsifying this most valuable type of raw material. The aim of this study was to study the macroand microstructure of white tea leaves from different manufacturers and to determine the morphological markers of the authenticity of white tea leaves. The objects of research were white tea from the Nandana Tea Factory (Sri Lanka) and white tea from an unknown manufacturer, purchased from a local tea shop. The study of raw materials was carried out in accordance with the requirements of GF XIV OFS 1.5.1.0003.15 ‘Leaves’ and OFS 1.5.3.0003.15 ‘Technique of microscopic and microchemical examination of medicinal plants and herbal medicinal products.’ The work was carried out on the basis of the laboratories of the Department of Food Technologies of FGBOU VO Saratov GAU named after N.I. Vavilov, and the Department of General Biology, Pharmacognosy and Botany, Saratov State Medical University named after V.I. Razumovsky Ministry of Health of Russia. Studies of the structure of white tea leaves from various manufacturers have shown that the structure and presence of morphological elements of leaves, such as hairs, stomata, leaf edge, druses, sclereids, differ markedly and can serve as reliable markers for identifying the variety of tea

The effect of bean flour addition on the rheological properties and baking quality of a triticale flour blends

Received: February 6th, 2021 ; Accepted: April 2nd, 2021 ; Published: August 18th, 2021 ; Correspondence: [email protected] aim of this research work was to study and compare the main parameters of the rheological state of the dough made from triticale flour (a variety of George selection by the FSBIS Agricultural Research Institute of the South-East), dough made from flour of white and red bean seeds, as well as parameters of dough from flour of composite mixtures based on them. The rheological properties of the dough were determined using a Mixolab device according to the GOST ISO 17718-2015 method. The mixing ability of the blends was additionally tested by the SDS sedimentation method. It was found that the moment of force, which characterizes the gelatinization process, correlates well with the SDS sedimentation index. To a lesser extent, this indicator correlates with the values of the moments of force characterizing the process of ‘starch retrogradation’ and the energy intensity of the dough formation process. The water absorption capacity of flour highly correlates with the moment of force during the liquefaction phase and with the moments of force characterizing the minimum and maximum consistency of the dough during the ‘starch retrogradation’ phase. The correlation between the SDS sedimentation rate and water absorption capacity was found to be rather low. The rheological parameters were also significantly influenced by the type of beans. Taking into account the results of studies of the rheological state of the dough, test baking of bread with various mass fractions of components was carried out. The results obtained confirmed the improving effect of bean flour

Muscle trematode infection of alien cyprinids in the basin of the Middle Ob (Sibiria, Russia)

The book represents proceedings of Sixth International Symposium “Invasion of Alien Species in Holarctic. Borok -VI” (11 Oct. – 15 Oct. 2021, Borok – Uglich, Russia). The wide spectrum of problems related to appearance and spread of invasive plants and animals is discussed. The book may be interested for specialists in many fields, such as limnologists, hydrobiologists, ecologists, botanists, zoologists, geographers, managers of dealing with nature preservation and fisheries

The role of non-commercial cyprinids in maintenance and spread of the opisthorchiasis focus in the middle Ob River basin (Tomsk region, Russia)

The study assessed the role of non-commercial cyprinid species in maintaining the opisthorchiasis focus in the middle Ob River basin, Tomsk region, Russia. The source of O. felineus infection for humans and carnivores is fish of the family Cyprinidae. This is the most numerous family, 14 species live in the middle Ob River basin, which includes 6 commercial species and 8 non-commercial species. This study aimed to investigate the current situation on infestation of non-commercial cyprinids with O. felineus metacercariae and their role in maintaining and spreading the natural focus of opisthorchiasis in the middle Ob River basin. We investigated 4 non-commercial species (tench, sunbleak, common bleak, gudgeon), which are highly abundant in water bodies. Tench, common bleak and gudgeon are objects of amateur fishing. These species are traditionally included in the diet of the local population. Opisthorchis felineus metacercariae were recorded in muscles of all the examined fish species. The identification of metacercariae was confirmed by morphological methods and PCR diagnostics. Tench and sunbleak are the main sources of opisthorchiasis infection in the floodplain lakes of the Ob River basin (the prevalence of tench infection is 89.3% and mean intensity of infection is 11.2 metacercariae per fish, the prevalence of sunbleak infection is 50.9% and the intensity of infection is 4.25 metacercariae per fish). The prevalence of infection in the introduced common bleak from the rivers of the middle Ob River basin is rapidly increasing from 2.4 (2016-2018) to 37.5% (2020-2021), and mean intensity of infection increased from 1 to 4.15. The epizootic state of water bodies in the middle Ob River basin remains unfavorable in relation to opisthorchiasis. Tench, common bleak and sunbleak, along with ide and dace, are the main source of infection for humans and animals, which is evidenced by high infection with Opisthorchis felineus metacercariae in these numerous fish species. They pose the greatest danger of infection of people and animals with opisthorchiasis. These species should be included in the campaign to avoid raw and poorly cooked fish in the diet. In addition, such species as roach, bream and sunbleak also pose the danger of infection with opisthorchiasis, but to a lesser extent

Tuning Pt characteristics on Pt/C catalyst for aqueous-phase reforming of biomass-derived oxygenates to bio-H-2

Pt/C catalysts with varied Pt sizes and distributions were investigated for aqueous-phase reforming (APR) of ethylene glycol (EG) to H2. APR experiments were performed on a continuous-flow fixed bed reactor with a catalyst loading of 1 g and EG feeding of 120 mL h−1 at 225 °C and 35 bar for 7 h. The fresh and used Pt/C catalysts were characterized by XRF, BET, CO chemisorption, TEM, XTEM, and XPS. Catalyst preparation protocols changed Pt characteristics on Pt/C catalysts, leading to a distinguishable H2 production. The rates for EG conversion and H2 production increased linearly with mean Pt size (3–11 nm), while having a volcano relationship with the mean size of agglomerated Pt particles (17–30 nm). Pt with concentrated Pt particles on surface of Pt/C catalysts was more preferable for APR of EG than the homogeneously distributed in catalysts. Optimal performance was obtained over a Pt/C-PR catalyst, which was prepared by precipitation method, showing a superb turnover frequency of 248 molH2 molPt−1 min−1 for H2 production from EG in APR. Besides, Pt/C catalysts also showed excellent stability. These results have shown the promise of Pt/C catalyst for APR of EG, which can be extended for bio-H2 production via APR of biomass-derived oxygenates in waste streams

Experimental Stand for Investigations of Insulator Degradation and Electrode Erosion in High-current Breaker

An experimental stand for studies of electric arc, electrode erosion and insulator degradation processes in high-current circuit breakers and some preliminary experimental data is described. The setup includes a discharge chamber, a capacitive energy storage with capacitance of 0.11 F, voltage up to 10 kV, and all necessary diagnostic techniques. The stand is designed for modeling current pulse with amplitude of 3–150 kA and duration of the first half period of 1.0–3.0  ms during the process of disconnecting the ring and the pin contacts. The arc is cooled by transverse gas blowing at pressure in the chamber of 0.5–3 MPa. Acquired experimental data can be used for verification of the modelling results of the heat transfer processes in the discharge chamber. At the stand, advanced composite materials based on carbon and iron-copper pseudoalloy are studied

Principles of healthcare management for patients with pulmonary hypertension: focus on continuity

In managing care for patients with rare, rapidly progressive pathologies such as pulmonary hypertension (PH) and chronic thromboembolic hypertension (CTEPH), early diagnosis and speed of routing are of particular importance. Reducing the time spent on patient routing reduces the risk of disease progression, the rate of hospitalizations, and thereby the socioeconomic burden of the disease.In the Republic of Karelia, an algorithm for routing patients with PH and CTEPH has been created, which is an example of a successful healthcare management

Эффективность различных методов компьютерной периметрии в диагностике первичной открытоугольной глаукомы. Часть 1

PURPOSE: To compare the diagnostic efficiency of 6 different computerized perimetric methods in patients with primary open-angle glaucoma (POAG) in an open comparative clinical research. METHODS: The study involved 52 patients (96 eyes) aged from 41 to 76 years old (average age 63 years) with POAG. Patients were divided into three groups depending on the stage of POAG: Group 1 included patients with mild (41 eyes), Group 2 - with moderate (36 eyes)and Group 3 -with advanced stages (19 eyes) of POAG. The control group consisted of 20 healthy persons (40 eyes) aged from 44 to 67 years old (average age 59 years). The patient examination included a standard ophthalmic assessment as well as computerized perimetry (CP) on Humphrey Visual Field Analyzer II (HFA II) 745i (Germany-USA), automated perimeters AP1000 («Tomey», Germany) and Pericom (Russian Federation), Micro-Perimeter MP-1 («Nidek Technologies», Japan), our modifications of Frequency Doubling Technology (FDT) perimetry and investigation of the multifocal Visual Evoked Potentials (mf VEP) as well as optical coherence tomography ОСТ RTVue-100 («Optovue», USA). RESULTS: FDT perimetry data demonstrated the same sensitivity (84%) as the HFA II ones (81%) and the greatest specificity (96%), the lowest variability of repeated results and the minimum testing time of one eye (1.5+0.04 min). Perimeters AP1000 and Pericom had lower levels of sensitivity (76/74%) and specificity (71/88%); the testing was longer (9.1+0.4 and 9.3+0.3 min). Data of MP-1 showed the high sensitivity (88%) and the lowest specificity (54%), the testing took place even longer (13.5+7.1 min.). The results of mf VEP had a quite high sensitivity (78%) and specificity (81%) and the maximum testing time of one eye (20.2+0.7 min.). CONCLUSION: To diagnose glaucoma, determine its stage and progression several methods of CP should be used. If it is impossible, it is necessary to repeat the same perimeter test a few times comparing perimetry data with the condition of the optic nerve head.ЦЕЛЬ. Сравнить диагностическую эффективность 6 методов компьютерной периметрии (КП) у пациентов с первичной открытоугольной глаукомой (ПОУГ) в рамках открытого сравнительного клинического исследования. МЕТОДЫ. В исследовании участвовали 52 больных (96 глаз) в возрасте от 41 года до 76 лет (средний возраст 63 года) с ПОУГ. В зависимости от стадии глаукомы пациентов разделили на 3 группы: 1-я - с начальной (41 глаз), 2-я - развитой (36 глаз) и 3-я - далекозашедшей (19 глаз) ПОУГ. В контрольную группу вошли 20 здоровых человек (40 глаз) в возрасте от 44 до 67 лет (средний возраст 59 лет). Наряду со стандартным офтальмологическим обследованием всем испытуемым проводили КП на анализаторе поля зрения Humphrey Visual Field Analyzer II (HFA II) 745i (Германия-США), автоматическом периметре AP1000 («Tomey», Германия), автоматическом статическом пери-графе Периком (Российская Федерация), микропериметре MP-1 («Nidek Technologies», Япония), а также наши модификации периметрии с технологией удвоения пространственной частоты - Frequency Doubling Technology (FDT) perimetry и исследования мультифокальных зрительных вызванных потенциалов (мфЗВП). Всем пациентам с ПОУГ выполняли оптическую когерентную томографию (ОСТ) на RTVue-100 («Optovue», США). РЕЗУЛЬТАТЫ. Данные FDT-периметрии, не уступая по уровню чувствительности HFA II (84/81%), показали самый высокий уровень специфичности (96%), наименьшую вариабельность повторных результатов и минимальное время тестирования одного глаза (1,5±0,04 мин.). AP-1000 и Периком имели более низкие уровни чувствительности (76/74%) и специфичности (71/88%) результатов, а тестирование было длительным (9,1±0,4 и 9,3±0,3 мин.). Данные МР-1 показали высокую чувствительность (88%) и самую низкую специфичность (54%), тестирование было еще более длительным (13,5±7,1 мин.). Результаты мфЗВП имели достаточно высокую чувствительность (78%) и специфичность (81%), длительность исследования одного глаза оказалась максимальной (20,2±0,7 мин.). ЗАКЛЮЧЕНИЕ. Для уточнения диагноза «глаукома», ее стадии, мониторинга заболевания следует при возможности использовать несколько методов КП, а при невозможности - неоднократно повторять имеющийся в наличии периметрический тест, сопоставляя данные периметрии с состоянием диска зрительного нерва

Hydrodeoxygenation of Isoeugenol over Alumina-Supported Ir, Pt, and Re Catalysts

Hydrodeoxygenation (HDO) of isoeugenol (IE) was investigated using bimetallic iridium rhenium and platinum rhenium catalysts supported on alumina in the temperature and pressure ranges of 200-250 degrees C and 17-40 bar in nonpolar dodecane as a solvent. The main parameters were catalyst type, hydrogen pressure, and initial concentration. Nearly quantitative yield of the desired product, propylcyclohexane (PCH), at complete conversion in 240 min was obtained with Ir-Re/Al2O3 prepared by the deposition-precipitation method using 0.1 mol/L IE initial concentration. High iridium dispersion together with a modification effect of rhenium provided in situ formation of the IrRe active component with reproducible catalytic activity for selective HDO of IE to PCH. The reaction rate was shown to increase with the increasing initial IE concentration promoting also HDO and giving a higher liquid phase mass balance. Increasing hydrogen pressure benefits the PCH yield

Analysis of Multiple Infection in Ixodic Ticks <i>Dermacentor reticulatus</i> in a Combined Natural Focus of Vector-Borne Infections in the Tomsk Region

The aim of the study was to characterize mono- and mixed infection with causative agents of vector-borne infections in Dermacentor reticulatus ticks inhabiting one of the anthropourgic foci of the Tomsk Region. Materials and methods. D. reticulatus ticks were collected from vegetation “on the flag” in the forest park zones of the southern part of Tomsk in August and September, 2020–2021. To isolate nucleic acids from homogenates of mites and subsequent PCR diagnostics, kits of the RealBest series (“Vector-Best”, Novosibirsk) were used. 184 individual samples of nucleic acids were examined for the presence of molecular-genetic markers of tick-borne encephalitis virus (TBEV), pathogenic borrelia, babesia, rickettsia, anaplasma, and ehrlichia. Results and discussion. The spectrum of pathogens detected through PCR assay of ticks collected in one of the anthropurgic foci of the Tomsk Region in 2020 and 2021 includes TBEV, pathogenic borrelia, rickettsia, and babesia. The highest rate of D. reticulatus infection has been established in relation to candidate pathogens of tick-borne rickettsioses (Rickettsia sp.) and babesioses (Babesia sp.). The overall frequency of co-infection in D. reticulatus was 12.88 %. Seven different associations of pathogens infecting D. reticulatus have been identified. The majority (88.24 %) of the detected cases of mixed infection were rickettsia associations. Double infection has been registered in 94 % of the total number of mixed variants. Markers of four tick-borne infection pathogens simultaneously (Rickettsia species DNA, Babesia species DNA, Borrelia burgdorferi s.l. DNA and TBEV RNA) have been found in one sample. Changes in areal of the D. reticulatus against the background of an increase in their numbers, determines the need to analyze the epidemiological significance of the ticks of this species in combined foci of tick-borne infections, especially in the zone of sympatry with ixodic ticks of other species