Cryo-STEM-EDX spectroscopy for the characterisation of nanoparticles in cell culture media

We present a study of barium titanate nanoparticles dispersed in cell culture media. Scanning transmission electron microscopy combined with energy dispersive X-ray spectroscopy was undertaken on samples prepared using both conventional drop casting and also plunge freezing and examination under cryogenic conditions. This showed that drying artefacts occurred during conventional sample preparation, whereby some salt components of the cell culture media accumulated around the barium titanate nanoparticles; these were removed using the cryogenic route. Importantly, the formation of a calcium and phosphorus rich coating around the barium titanate nanoparticles was retained under cryo-conditions, highlighting that significant interactions do occur between nanomaterials and biological media

Cycles of construing in radicalization and deradicalization: a study of Salafist Muslims.

© Taylor & Francis Group, LLC.This article explores radicalization and deradicalization by considering the experiences of six young Tunisian people who had become Salafist Muslims. Their responses to narrative interviews and repertory grid technique are considered from a personal construct perspective, revealing processes of construing and reconstruing, as well as relevant aspects of the structure and content of their construct systems. In two cases, their journeys involved not only radicalization but self-deradicalization, and their experiences are drawn on to consider implications for deradicalization.Peer reviewedFinal Accepted Versio

Скринінг гіпоглікемічної активності екстрактів з листя Мучниці звичайної та вивчення гострої токсичності

Diabetes mellitus type 2 (DM2) is a global health problem. The plant origin medicinal preparations revealed different mechanisms of antidiabetic action. Despite a wide range of plants that have already been studied, other species are of interest. Particularly, Bearberry (Arctostaphylos uva-ursi) attracted our attention because its leaves are rich with biologically active compounds, but hypoglycemic activity has not been studied yet.The aim of our experiment was studding acute toxicity and hypoglycemic activity of Bearberry extracts on non-diabetic standard models.Materials and methods. It was conducted the screening of hypoglycemic effect in healthy rats, oral glucose tolerance test in healthy rats and study of acute toxicity. The object of study were water and alcohol polyphenol extracts of Bearberry leaves (extractor –alcohol 50 % and 90 %). Results and discussion. Screening and comparative study shows that the maximal hypoglycemic activity revealed Bearberry leaves alcohol extract (extractor – 50 % ethanol, PE50) in dose 100 mg/kg. The least pronounced effect was observed for the introduction of water extract administration.Conclusions. The results indicate the practicability of this Bearberry leaves extract further study for renewal the range of medicinal products that revealed hypoglycemic activity.Сахарный диабет 2 типа (СД2) является глобальной проблемой здравоохранения. Эффективность лекарственных препаратов растительного происхождения объясняется различными механизмами антидиабетического действия. Несмотря на широкий спектр изученных растений, интерес представляют и другие виды. В частности, Толокнянка обыкновенная (Arctostaphylos uva-ursi) представляет научный интерес, так как ее листья богаты биологически активными соединениями, однако их гипогликемическая активность еще не изучена.Целью нашего эксперимента было изучение острой токсичности и гипогликемической активности экстрактов Толокнянки обыкновенной на недиабетических стандартных моделях.Материалы и методы. Было проведено исследование гипогликемической активности на здоровых крысах, пероральный тест толерантности к глюкозе на здоровых крысах и исследование острой токсичности. Объектом исследования были водный и спиртовые полифенольные экстракты листьев Толокнянки обыкновенной (экстрагент – алкоголь 50 % и 90 %).Результаты и их обсуждение. Скрининг и сравнительное исследование показывают, что максимальную гипогликемическую активность проявил спиртовый экстракт из листьев Толокнянки обыкновенной (экстрагент – 50 % этанола, PE50) в дозе 100 мг/кг. Наименьший гипогликемический эффект наблюдался при введении водного экстракта.Выводы. Результаты показали целесообразность дальнейшего изучения экстракта листьев Толокнянки обыкновенной для пополнения ассортимента лекарственных препаратов с гипогликемической активностью.Цукровий діабет 2 типу (ЦД2) є глобальною проблемою охорони здоров’я. Ефективність лікарських препаратів рослинного походження пояснюється різними механізмами антидіабетичної дії. Незважаючи на широкий спектр рослин, які вже піддавалися вивченню, інтерес представляють і інші види. Зокрема, Мучниця звичайна (Arctostaphylos uva-ursi) привернула нашу увагу, так як її листя багате на біологічно активні сполуки, однак їх гіпоглікемічна активність ще не вивчена.Мета даного експерименту полягала у вивченні гострої токсичності та гіпоглікемічної активності екстрактів Мучниці звичайної на стандартних моделях у здорових щурів.Матеріали та методи. Було проведено дослідження гіпоглікемічної активності на здорових щурах, пероральний тест толерантності до глюкози на здорових щурах і дослідження гострої токсичності. Об’єктом дослідження були водний і спиртові поліфенольні екстракти листя мучниці звичайної (екстрагент – етанол 50 % і 90 %).Результати та їх обговорення. Скринінг і порівняльне дослідження показують, що максимальну гіпоглікемічну активність проявив спиртовий екстракт з листя Мучниці звичайної (екстрагент – 50 % етанолу, PE50) в дозі 100 мг/кг. Найменший гіпоглікемічний ефект спостерігався при введенні водного екстракту.Висновки. Результати показали доцільність подальшого вивчення екстракту листя Мучниці звичайної для оновлення асортименту лікарських препаратів з гіпоглікемічною активністю

Dynamics of surfactant-laden evaporating droplets

We consider the flow dynamics of a thin evaporating droplet in\ud the presence of an insoluble surfactant and small particles in the bulk. Evolution\ud equations for the film height, the interfacial surfactant and bulk particle concentra-\ud tion are derived using a lubrication model coupled by a constitutive relation for the\ud dependence of the viscosity on local particle concentration. An important ingredient\ud of our model is that it takes into account the fact that the surfactant adsorbed at\ud the surface hinders the evaporation. Time-dependent simulations are performed to\ud determine how the presence of surfactants affects the evaporation and flow dynamics\ud with and without the presence of particles in the bulk. We discuss the various mech-\ud anisms that affect the shape of the droplet as it evaporates as well as the resulting\ud pattern of particle deposition

Use of tumour markers in gastrointestinal cancers: surgeon perceptions and cost-benefit trade-off analysis

Background: Gastrointestinal cancers constitute the third most common cancers worldwide. Tumor markers have long since been used in the postoperative surveillance of these malignancies; however, the true value in clinical practice remains undetermined. Objective: This study aimed to evaluate the clinical utility of three tumor markers in colorectal and esophagogastric cancer. Methods: A systematic review of the literature was undertaken to elicit the sensitivity, specificity, statistical heterogeneity and ability to predict recurrence and metastases for carcinoembryonic antigen (CEA), cancer antigen (CA) 19-9 and CA125. European surgeons were surveyed to assess their current practice and the characteristics of tumor markers they most valued. Data from the included studies and survey were combined in a cost-benefit trade-off analysis to assess which tumor markers are of most use in clinical practice. Results: Diagnostic sensitivity and specificity were ranked the most desirable characteristics of a tumor marker by those surveyed. Overall, 156 studies were included to inform the cost-benefit trade-off. The cost-benefit trade-off showed that CEA outperformed both CA19-9 and CA125, with lower financial cost and a higher sensitivity, and diagnostic accuracy for metastases at presentation (area under the curve [AUC] 0.70 vs. 0.61 vs. 0.46), as well as similar diagnostic accuracy for recurrence (AUC 0.46 vs. 0.48). Conclusions: Cost-benefit trade-off analysis identified CEA to be the best performing tumor marker. Further studies should seek to evaluate new tumor markers, with investigation tailored to factors that meet the requirements of practicing clinicians

Hybrid in vitro diffusion cell for simultaneous evaluation of hair and skin decontamination: temporal distribution of chemical contaminants

Most casualty or personnel decontamination studies have focused on removing contaminants from the skin. However, scalp hair and underlying skin are the most likely areas of contamination following airborne exposure to chemicals. The aim of this study was to investigate the interactions of contaminants with scalp hair and underlying skin using a hybrid in vitro diffusion cell model. The in vitro hybrid test system comprised “curtains” of human hair mounted onto sections of excised porcine skin within a modified diffusion cell. The results demonstrated that hair substantially reduced underlying scalp skin contamination and that hair may provide a limited decontamination effect by removing contaminants from the skin surface. This hybrid test system may have application in the development of improved chemical incident response processes through the evaluation of various hair and skin decontamination strategies.Peer reviewedFinal Published versio

The stability of slowly evaporating thin liquid films of binary mixtures

We consider the evaporation of a thin liquid layer which consists of a binary mixture of volatile liquids. The mixture is on top of a heated substrate and in contact with the gas phase that consists of the same vapour as the binary mixture. The effect of thermocapillarity, solutocapillarity and the van der Waals interactions are considered. We derive the long-wave evolution equations for the free interface and the volume fraction that govern the two-dimensional stability of the layer subject to the above coupled mechanisms and perform a linear stability analysis. Our results demonstrate two modes of instabilities, a monotonic instability mode and an oscillatory instability mode. We supplement our results from stability analysis with transient simulations to examine the dynamics in the nonlinear regime and analyse how these instabilities evolve with time. More precisely we discuss how the effect of relative volatility along with the competition between thermal and solutal Marangoni effect defines the mode of instability that develops during the evaporation of the liquid layer due to preferential evaporation of one of the components.Comment: 19 page

A machine learning approach to the prediction of heat-transfer coefficients in micro-channels

The accurate prediction of the two-phase heat transfer coefficient (HTC) as a function of working fluids, channel geometries and process conditions is key to the optimal design and operation of compact heat exchangers. Advances in artificial intelligence research have recently boosted the application of machine learning (ML) algorithms to obtain data-driven surrogate models for the HTC. For most supervised learning algorithms, the task is that of a nonlinear regression problem. Despite the fact that these models have been proven capable of outperforming traditional empirical correlations, they have key limitations such as overfitting the data, the lack of uncertainty estimation, and interpretability of the results. To address these limitations, in this paper, we use a multi-output Gaussian process regression (GPR) to estimate the HTC in microchannels as a function of the mass flow rate, heat flux, system pressure and channel diameter and length. The model is trained using the Brunel Two-Phase Flow database of high-fidelity experimental data. The advantages of GPR are data efficiency, the small number of hyperparameters to be trained (typically of the same order of the number of input dimensions), and the automatic trade-off between data fit and model complexity guaranteed by the maximization of the marginal likelihood (Bayesian approach). Our paper proposes research directions to improve the performance of the GPR-based model in extrapolation.Comment: 7 pages, 2 figures, to be published in the proceedings of the 17th International Heat Transfer Conference 2023 (IHTC-17