Cr cluster characterization in Cu-Cr-Zr alloy after ECAP processing and aging using SANS and HAADF-STEM

International audienceThe precipitation of nano-sized Cr clusters was investigated in a commercial Cu-1Cr-0.1Zr (wt.%) alloy processed by Equal-Channel Angular Pressing (ECAP) and subsequent aging at 550 °C for 4 hours using small angle neutron scattering (SANS) measurements and high-angle annular dark-field-scanning transmission electron microscopy (HAADF-STEM). The size and volume fraction of nano-sized Cr clusters were estimated using both techniques. These parameters assessed from SANS (d~3.2 nm, Fv~1.1 %) agreed reasonably with those from HAADF-STEM (d ~2.5 nm, Fv~2.3%). Besides nano-sized Cr clusters, HAADF-STEM technique evidenced the presence of rare cuboid and spheroid sub-micronic Cr particles about 380-620 nm mean size. Both techniques did not evidence the presence of intermetallic CuxZry phases within the aging conditions

On some Features of the Grain and Subgrain Size in a Cu-Cr-Zr Alloy After ECAP Processing and Aging

A Cu-1Cr-0.1Zr alloy has been subjected to ECAP processing via route Bc and aging at 250-800°C. Electron BackScatter diffraction (EBSD), Transmission Electron Microscopy (TEM) and X-Ray Diffraction Line Profile Analysis (XRDLPA) techniques have been used to unveil some peculiarities of the grain and subgrain structure with a special emphasis on the comparison of the grain size estimated by the three techniques. For the alloy ECAP processed and aged up to 16 passes, the grain size (from EBSD, 0.2 < d < 5 μm), subgrain size (from TEM, d ~ 0.75 μm) and “apparent” average crystallite size (from XRDLPA, d < 0.25 μm) are manifestly different. The results were compared to the published data and analyzed based on the fundamental aspects of these techniques

The Recognition of N-Glycans by the Lectin ArtinM Mediates Cell Death of a Human Myeloid Leukemia Cell Line

ArtinM, a d-mannose-binding lectin from Artocarpus heterophyllus (jackfruit), interacts with N-glycosylated receptors on the surface of several cells of hematopoietic origin, triggering cell migration, degranulation, and cytokine release. Because malignant transformation is often associated with altered expression of cell surface glycans, we evaluated the interaction of ArtinM with human myelocytic leukemia cells and investigated cellular responses to lectin binding. The intensity of ArtinM binding varied across 3 leukemia cell lines: NB4>K562>U937. The binding, which was directly related to cell growth suppression, was inhibited in the presence of Manα1-3(Manα1-6)Manβ1, and was reverted in underglycosylated NB4 cells. ArtinM interaction with NB4 cells induced cell death (IC50 = 10 µg/mL), as indicated by cell surface exposure of phosphatidylserine and disruption of mitochondrial membrane potential unassociated with caspase activation or DNA fragmentation. Moreover, ArtinM treatment of NB4 cells strongly induced reactive oxygen species generation and autophagy, as indicated by the detection of acidic vesicular organelles in the treated cells. NB4 cell death was attributed to ArtinM recognition of the trimannosyl core of N-glycans containing a ß1,6-GlcNAc branch linked to α1,6-mannose. This modification correlated with higher levels of N-acetylglucosaminyltransferase V transcripts in NB4 cells than in K562 or U937 cells. Our results provide new insights into the potential of N-glycans containing a β1,6-GlcNAc branch linked to α1,6-mannose as a novel target for anti-leukemia treatment

Intervening with Urinary Tract Infections Using Anti-Adhesives Based on the Crystal Structure of the FimH–Oligomannose-3 Complex

Escherichia coli strains adhere to the normally sterile human uroepithelium using type 1 pili, that are long, hairy surface organelles exposing a mannose-binding FimH adhesin at the tip. A small percentage of adhered bacteria can successfully invade bladder cells, presumably via pathways mediated by the high-mannosylated uroplakin-Ia and alpha3beta1 integrins found throughout the uroepithelium. Invaded bacteria replicate and mature into dense, biofilm-like inclusions in preparation of fluxing and of infection of neighbouring cells, being the major cause of the troublesome recurrent urinary tract infections.We demonstrate that alpha-D-mannose based inhibitors of FimH not only block bacterial adhesion on uroepithelial cells but also antagonize invasion and biofilm formation. Heptyl alpha-D-mannose prevents binding of type 1-piliated E. coli to the human bladder cell line 5637 and reduces both adhesion and invasion of the UTI89 cystitis isolate instilled in mouse bladder via catheterization. Heptyl alpha-D-mannose also specifically inhibited biofilm formation at micromolar concentrations. The structural basis of the great inhibitory potential of alkyl and aryl alpha-D-mannosides was elucidated in the crystal structure of the FimH receptor-binding domain in complex with oligomannose-3. FimH interacts with Man alpha1,3Man beta1,4GlcNAc beta1,4GlcNAc in an extended binding site. The interactions along the alpha1,3 glycosidic bond and the first beta1,4 linkage to the chitobiose unit are conserved with those of FimH with butyl alpha-D-mannose. The strong stacking of the central mannose with the aromatic ring of Tyr48 is congruent with the high affinity found for synthetic inhibitors in which this mannose is substituted for by an aromatic group.The potential of ligand-based design of antagonists of urinary tract infections is ruled by the structural mimicry of natural epitopes and extends into blocking of bacterial invasion, intracellular growth and capacity to fluxing and of recurrence of the infection

Concepts for the development of person-centred, digitally-enabled, Artificial Intelligence-assisted ARIA care pathways (ARIA 2024)

The traditional healthcare model is focused on diseases (medicine and natural science) and does not acknowledge patients' resources and abilities to be experts in their own life based on their lived experiences. Improving healthcare safety, quality and coordination, as well as quality of life, are important aims in the care of patients with chronic conditions. Person-centred care needs to ensure that people's values and preferences guide clinical decisions. This paper reviews current knowledge to develop (i) digital care pathways for rhinitis and asthma multimorbidity and (ii) digitally-enabled person-centred care (1). It combines all relevant research evidence, including the so-called real-world evidence, with the ultimate goal to develop digitally-enabled, patient-centred care. The paper includes (i) Allergic Rhinitis and its Impact on Asthma (ARIA), a two-decade journey, (ii) Grading of Recommendations, Assessment, Development and Evaluation (GRADE), the evidence-based model of guidelines in airway diseases, (iii) mHealth impact on airway diseases, (iv) from guidelines to digital care pathways, (v) embedding Planetary Health, (vi) novel classification of rhinitis and asthma, (vi) embedding real-life data with population-based studies, (vii) the ARIA-EAACI strategy for the management of airway diseases using digital biomarkers, (viii) Artificial Intelligence, (ix) the development of digitally-enabled ARIA Person-Centred Care and (x) the political agenda. The ultimate goal is to propose ARIA 2024 guidelines centred around the patient in order to make them more applicable and sustainable

Photometric determination of phosphate-ions concentration by Zirconium-Arsenazo I Complex

Повышение уровня питательных веществ (азота, фосфора) в природных водах является причиной эвтрофикации. Это приводит к гипоксии водоемов, отравлению воды токсинами водорослей, гибели рыб и других водных организмов. Поля стока (выщелачивание удобрений из почв) и неэффективно очищенные сточные воды являются основными источниками питательных веществ. Многие умягчители воды и стиральные порошки содержат фосфаты.Таким образом статья посвящена новому методу простого, быстрого и эффективного определения фосфатов в пробах воды, почвы и моющих средств

Мышьяксодержащие отходы водоочистки: возможные пути утилизации

Більшість сполук арсену є високотоксичними, в результаті чого потрапляння цих речовин в людський організм разом з водою чи їжею або тривалий контакт зі шкірою призводить до численних проблем зі здоров’ям (гіперкератоз, меланоз, ракові захворювання, ендокринні розлади, генотоксичні ефекти тощо), що робить видалення сполук арсену дуже важливим процесом у водоочищенні. Природні води багатьох країн та стічні води деяких підприємств містять великі концентрації сполук арсену, які в результаті процесів водоочищення переходять у різноманітні тверді та рідкі відходи (коагуляційні шлами, відпрацьовані адсорбенти, регенераційні розчини, концентрат зі стадії зворотного осмосу тощо). Зазвичай сполуки арсену іммобілізуються у вигляді нерозчинних сполук феруму в результаті перебігу коагуляції чи ряду інших процесів водоочищення. Ферум (III) арсенат та деякі інші арсенати мають набагато нижчу розчинність в лужному середовищі, тобто бажано зберігати і використовувати ці відходи разом зі сполуками, що забезпечують лужну реакцію. Одним з таких матеріалів є цемент, який характеризується високими значеннями рН, а вміст арсену в цементі не нормується, оскільки організм людини безпосередньо не контактує з цементом. Результати експериментів довели, що утилізація забруднених арсеном адсорбентів у вигляді цементних виробів є відносно безпечною за вмісту арсену 53,3-142,2 мкг/г, оскільки вимивання арсенатів не відбулося навіть за 7 днів. Відпрацьовані залізовмісні адсорбенти мають перспективи як забарвлюючі добавки бетонних виробів, оскільки навіть незначна кількість Fe2O3 надає готовим бетонним виробам приємний лососевий відтінок. Різні сполуки феруму (III) можуть надавати спектр відтінків бетонним виробам (жовтуваті, охристі, коричневі, лососеві тощо), що є перспективним в контексті виробництва тротуарної плитки, будівельних матеріалів та в деяких інших галузях.Iron (III) arsenate and some other arsenates have a much lower solubility in an alkaline environment, that is, it is advisable to store and use these wastes together with compounds that provide an alkaline reaction. Cement is characterized by high pH values, and the content of arsenic in cement is not normalized, because the human body does not directly contact with cement. The experimental results proved that utilization of arsenic-containing adsorbents in the form of concrete products was safe in case of arsenic content from 53.3-142.2 μg/g and had perspectives in colouring of concrete products.Арсенат железа (III) и некоторые другие арсенаты имеют гораздо более низкую растворимость в щелочной среде, то есть желательно хранить и использовать эти отходы вместе с соединениями, обеспечивающими щелочную реакцию. Цемент характеризуется высокими значениями рН, а содержание мышьяка в цементе не нормируется, поскольку организм человека напрямую не контактирует с цементом. Результаты экспериментов доказали, что утилизация мышьяксодержащих адсорбентов в виде цементных изделий является безопасным при содержании мышьяка 53,3-142,2 мкг/г и имеет перспективы в окрашивании бетонных изделий

Morphology and chemical composition of Cu/Sn/Cu and Cu(5 at-%Ni)/Sn/Cu(5 at-%Ni) interconnections

In the present paper, scanning and transmission electron microscopies as well as energy dispersive X-ray spectroscopy investigations were performed to describe the morphology and chemical composition of the intermetallic phases growing in Cu/Sn/Cu and Cu(Ni)/Sn/Cu(Ni) interconnections during the diffusion soldering process. The obtained results revealed that even a small amount of Ni addition (5 at-%) to the Cu substrate totally changes the morphology and the rate of formation of the intermetallic phase layers in the solder/substrate reaction zone of the interconnections prepared at the same time and joining temperature conditions. The presented studies are promising in terms of the shortening of the soldering time in the elecronic industry