Sсandium(III) Beta-diketonate Derivatives as Precursors for Oxide Film Deposition by CVD

AbstractComplexes with acetylacetone Sc(acac)3, dipivaloylmethane Sc(thd)3, 2,2,6,6–tetramethyl-4-fluoro-3,5-heptanedione Sc(tfhd)3, pivaloyltrifluoroacetone Sc(ptac)3, trifluoroacetylacetone Sc(tfac)3, and hexafluoroacetylacetone Sc(hfac)3 were synthesized, purified and identified by elemental analysis, m.p., IR and NMR spectroscopy, and mass spectrometry. The thermal behaviour of the synthesized compounds in the solid state was investigated by the method of difference-scanning calorimetry in vacuum. As a result the thermodynamic characteristics of the melting processes were determined. The temperature dependences of saturated and unsaturated vapour pressure of complexes under study were measured by static method with membrane-gauge manometers. The average molecular weight of gas calculated from the experimental data on unsaturated vapours using ideal gas law was close to the molecular weight of monomer for all investigated compounds. Decomposition temperatures of compounds under study were defined as the temperature above that pressure changes became irreversible. The information about melting and decomposition processes were taken into account at measuring saturated vapour pressure of complexes. The row of volatility Sc(hfac)3 > Sc(ptac)3 > Sc(tfac)3 > Sc(thd)3 ≥ Sc(tfhd)3 > Sc(acac)3 was determined from the p–T dependences obtained. Above information about thermal behaviour of complexes enabled one to use it as a guide for CVD experiments aimed at achieving oxide films with high optical properties. Precursor chosen for film deposition was Sc(thd)3 The Sc2O3 film deposition conditions were following: the gas-carrier rate 1 l/h, He gas-reagent rate 10 l/h, total pressure 10 Torr, evaporator temperature 105-110̊С, substrate temperature 450- 650̊С, substrate Si(100). Ellipsometry was applied to characterize the film thickness and refractive index. The morphology and the composition of the films were determined with XPS and SEM

The politics of in/visibility: carving out queer space in Ul'yanovsk

<p>In spite of a growing interest within sexualities studies in the concept of queer space (Oswin 2008), existing literature focuses almost exclusively on its most visible and territorialised forms, such as the gay scene, thus privileging Western metropolitan areas as hubs of queer consumer culture (Binnie 2004). While the literature has emphasised the political significance of queer space as a site of resistance to hegemonic gender and sexual norms, it has again predominantly focused on overt claims to public space embodied in Pride events, neglecting other less open forms of resistance.</p><p> This article contributes new insights to current debates about the construction and meaning of queer space by considering how city space is appropriated by an informal queer network in Ul’ianovsk. The group routinely occupied very public locations meeting and socialising on the street or in mainstream cafés in central Ul’ianovsk, although claims to these spaces as queer were mostly contingent, precarious or invisible to outsiders. The article considers how provincial location affects tactics used to carve out communal space, foregrounding the importance of local context and collective agency in shaping specific forms of resistance, and questioning ethnocentric assumptions about the empowering potential of visibility.</p&gt

Еколого-токсикологічний скринінг безпечності питної води для тваринницьких підприємств Одеської області

Our scientific and industrial research aimed to determine tap water's safety for watering productive animals (cows, goats, sheep) in three different livestock enterprises of the Odesa region. By using the microbiological method - ecological-toxicological express biotesting (with the help of the preparation of test organisms of the dry culture of ciliates Colpoda steinii), it was determined that among 106 samples of tap water for watering animals, an average of 65.62 received a rating of “general weak toxicity”; 67.01 and 64.88 % of the samples, respectively, for each farm (P < 0.001, which highlighted the problem of the unsatisfactory quality of drinking tap water for dairy cattle. A trend was established to increase the indicator of weak toxicity of drinking water in enterprises by +0.22–4.33 % during the year in each farm (P < 0.001). Determination of the comprehensive indicator of the quality of tap water for watering animals (farm No. 3) by express analysis of samples by the TDS - metric method showed that the level of mineralization of untreated drinking water exceeded recommended norms in 27.65 and 31.17 times (in 2023 and 2024, respectively, (P < 0.001), and samples of water purified on the “ECOSOFT-6500” line were within the recommended norms of high-quality drinking water: on average 35.63–33.59 mg/l, respectively (P < 0.001). The analysis of experimental comparative data and literature sources showed the need for further studies on the quality and safety of water for watering productive animals to optimize the management of safe water supply and obtain organic livestock products.Метою нашого науково-виробничого дослідження було визначення безпечності водопровідної води для напування продуктивних тварин (корови, кози, вівці) у трьох різних тваринницьких підприємствах Одеської області. Шляхом використання мікробіологічного методу – еколого-токсикологічного експрес-біотестування (з допомогою препарату тест-організмів сухої культури інфузорій Colpoda steinii) було визначено, що серед 106 зразків водопровідної води для напування тварин, оцінку “загальна слабка токсичність” отримали в середньому 65,62; 67,01 і 64,88 % проб відповідно для кожного господарства (P < 0,001), що висвітлило проблему незадовільного стану якості питної водопровідної води для молочного поголів’я. Встановлена стала тенденція до росту показнику слабкої токсичності питної води у підприємствах на +0,22–4,33 % впродовж року в кожному господарстві (P < 0,001). Визначення комплексного показника якості водопровідної води для напування тварин (господарство № 3) шляхом експрес-аналізу зразків методом TDS-метрії показало, що рівень мінералізації неочищеної питної води перевищував рекомендовані нормативи в 27,65 і 31,17 раза (відповідно у 2023 і 2024 роках (P < 0,001), а зразки очищеної на лінії “ECOSOFT-6500” води були в межах рекомендованих норм якісної питної води: у середньому 35,63–33,59 мг/л, відповідно (P < 0,001). Аналіз експериментальних порівняльних даних і літературних джерел показав необхідність подальших досліджень з вивчення якості та безпечності води для напування продуктивних тварин з метою оптимізації менеджменту безпечного водопостачання і отримання органічної тваринницької продукції

Contribution of Aquaporins to Cellular Water Transport Observed by a Microfluidic Cell Volume Sensor

Here we demonstrate that an impedance-based microfluidic cell volume sensor can be used to study the roles of aquaporin (AQP) in cellular water permeability and screen AQP-specific drugs. Human embryonic kidney (HEK-293) cells were transiently transfected with AQP3- or AQP4-encoding genes to express AQPs in plasma membranes. The swelling of cells in response to hypotonic stimulation was traced in real time using the sensor. Two time constants were obtained by fitting the swelling curves with a two-exponential function, a fast time constant associated with osmotic water permeability of AQP-expressing cells and a slow phase time constant associated mainly with water diffusion through lipid bilayers in the nontransfected cells. The AQP-expressing cells showed at least 10× faster osmotic water transport than control cells. Using the volume sensor, we examined the effects of Hg2+ and Ni2+ on the water transport via AQPs. Hg2+ inhibited the water flux in AQP3-expressing cells irreversibly, while Ni2+ blocked the AQP3 channels reversibly. Neither of the two ions blocked the AQP4 channels. The microfluidic volume sensor can sense changes in cell volume in real time, which enables perfusion of various reagents sequentially. It provides a convenient tool for studying the effect of reagents on the function and regulation mechanism of AQPs

Stable multicolor periodic-wave arrays

We study the existence and stability of cnoidal periodic wave arrays propagating in uniform quadratic nonlinear media and discover that they become completely stable above a threshold light intensity. To the best of our knowledge, this is the first example in physics of completely stable periodic wave patterns propagating in conservative uniform media supporting bright solitons.Comment: 12 pages, 3 figure

Potassium Dependent Regulation of Astrocyte Water Permeability Is Mediated by cAMP Signaling

Astrocytes express potassium and water channels to support dynamic regulation of potassium homeostasis. Potassium kinetics can be modulated by aquaporin-4 (AQP4), the essential water channel for astrocyte water permeability regulation. We investigated whether extracellular potassium ([K+]o) can regulate astrocyte water permeability and the mechanisms of such an effect. Studies were performed on rat primary astrocytes and a rat astrocyte cell line transfected with AQP4. We found that 10mM [K+]o caused an immediate, more than 40%, increase in astrocyte water permeability which was sustained in 5min. The water channel AQP4 was a target for this regulation. Potassium induced a significant increase in intracellular cAMP as measured with a FRET based method and with enzyme immunoassay. We found that protein kinase A (PKA) could phosphorylate AQP4 in vitro. Further elevation of [K+]o to 35mM induced a global intracellular calcium response and a transient water permeability increase that was abolished in 5min. When inwardly rectifying potassium (Kir)-channels were blocked, 10mM [K+]o also induced a calcium increase and the water permeability increase no longer persisted. In conclusion, we find that elevation of extracellular potassium regulates AQP4 and astrocyte water permeability via intracellular signaling involving cAMP. A prolonged increase of astrocyte water permeability is Kir-channel dependent and this response can be impeded by intracellular calcium signaling. Our results support the concept of coupling between AQP4 and potassium handling in astrocytes

Immunohistochemical localization and mRNA expression of aquaporins in the macula utriculi of patients with Meniere’s disease and acoustic neuroma

Meniere’s disease is nearly invariably associated with endolymphatic hydrops (the net accumulation of water in the inner ear endolymphatic space). Vestibular maculae utriculi were acquired from patients undergoing surgery for Meniere’s disease and acoustic neuroma and from autopsy (subjects with normal hearing and balance). Quantitative immunostaining was conducted with antibodies against aquaporins (AQPs) 1, 4, and 6, Na+K+ATPase, Na+K+2Cl co-transporter (NKCC1), and α-syntrophin. mRNA was extracted from the surgically acquired utricles from subjects with Meniere’s disease and acoustic neuroma to conduct quantitative real-time reverse transcription with polymerase chain reaction for AQP1, AQP4, and AQP6. AQP1 immunoreactivity (−IR) was located in blood vessels and fibrocytes in the underlying stroma, without any apparent alteration in Meniere’s specimens when compared with acoustic neuroma and autopsy specimens. AQP4-IR localized to the epithelial basolateral supporting cells in Meniere’s disease, acoustic neuroma, and autopsy. In specimens from subjects with Meniere’s disease, AQP4-IR was significantly decreased compared with autopsy and acoustic neuroma specimens. AQP6-IR occurred in the sub-apical vestibular supporting cells in acoustic neuroma and autopsy samples. However, in Meniere’s disease specimens, AQP6-IR was significantly increased and diffusely redistributed throughout the supporting cell cytoplasm. Na+K+ATPase, NKCC1, and α-syntrophin were expressed within sensory epithelia and were unaltered in Meniere’s disease specimens. Expression of AQP1, AQP4, or AQP6 mRNA did not differ in vestibular endorgans from patients with Meniere’s disease. Changes in AQP4 (decreased) and AQP6 (increased) expression in Meniere’s disease specimens suggest that the supporting cell might be a cellular target

Physiology and pathophysiology of the vasopressin-regulated renal water reabsorption

To prevent dehydration, terrestrial animals and humans have developed a sensitive and versatile system to maintain their water homeostasis. In states of hypernatremia or hypovolemia, the antidiuretic hormone vasopressin (AVP) is released from the pituitary and binds its type-2 receptor in renal principal cells. This triggers an intracellular cAMP signaling cascade, which phosphorylates aquaporin-2 (AQP2) and targets the channel to the apical plasma membrane. Driven by an osmotic gradient, pro-urinary water then passes the membrane through AQP2 and leaves the cell on the basolateral side via AQP3 and AQP4 water channels. When water homeostasis is restored, AVP levels decline, and AQP2 is internalized from the plasma membrane, leaving the plasma membrane watertight again. The action of AVP is counterbalanced by several hormones like prostaglandin E2, bradykinin, dopamine, endothelin-1, acetylcholine, epidermal growth factor, and purines. Moreover, AQP2 is strongly involved in the pathophysiology of disorders characterized by renal concentrating defects, as well as conditions associated with severe water retention. This review focuses on our recent increase in understanding of the molecular mechanisms underlying AVP-regulated renal water transport in both health and disease