Investigation of influence of electromagnetic field on electrochemical behaviour of heavy metal ions in the presence of butanol

By the method of inversion voltamperometry the action of high-frequency electromagnetic field of radio-frequiency bandwidth on current of anode peak Zn(II), Cd(II) and Pb(II) in the presence of butanol, molecules of which are adsorbed on the electron surface decreasing its free surface has been studied. As a result of the field influence on electrode-electrolyte system removing of electrode processes inhibition is shown to take place, it is conditioned by desorbtion of adsorbate molecules from electron surface. Desorbing action of high-frequency current is proved by measuring degree of electrode filling with butanol molecules and Frumkin's adsorbtion equation parameters

Studies of Urban Identities in Siberian Urban History

The article was submitted on 11.11.2019.This article considers the main results of identity research on Siberian urban history. The author identifies the seven most extensively developed topics in studying the history of urban identities. The first topic focuses on the formation of a city’s general identity in the initial stages of its formation. Historians aim to reveal the mechanisms of general city identification, as well as the sources, criteria, and values underlying the identity of a particular city. The second topic includes studies of the drift of urban production and industrial identities in the context of industrialization: quite often, it was industrial markers that determined the direction of a city’s identification. The third topic covers the study of ethnicity in urban spaces. Historians reveal the reaction of ethnicity to processes of adaptation and acculturation. The fourth issue concerns the study of gender identity in the context of the masculine orientation of urbanisation processes. Historians focus on the study of mechanisms underlying the dominance of masculine culture in the urban environment and the development of the socio-cultural significance and functions of women, their limitations and emancipation. The fifth topic concerns the identification of social stratification in urban systems. Urban history gains new nowledge through studies which examine urbanisation as a factor of differentiation in urban society and classical structures of society (estates and classes), as well as in works on the identification of the middle class, social mobility, the formation of marginal groups, and vernacular culture. The sixth topic is expanded by works dealing with the historical imagology of the city. Images are forms of identity representations in cultural and public discourses. Therefore, in studying them, urban history today makes a practical contribution to the development of modern urbanism. The seventh topic focuses on the historiographical analysis of the identification research strategies of urban historians themselves. In the process of revealing urban identities, the research model should be based on a wide range of sources of a predominantly narrative nature and the anthropological approach. It seems appropriate to use the potential of memoirs, oral history, periodicals, fiction, and journalistic literature. Studies on the identity palette of Russian urban history go beyond purely historical issues and are based on deep interdisciplinary interaction.Рассматриваются основные результаты исследований идентичности в сибирской исторической урбанистике. Автор выделяет семь наиболее разрабатываемых тем в изучении истории городских идентичностей. Первая концентрируется на раскрытии формирования общегородской идентичности в процессе начального становления городов. Историки стремятся выявить механизмы выстраивания общегородской идентификации, ее источники, критерии и ценности, на которых она строится в том или ином городе. Вторая включает исследования дрейфа городских производственно-отраслевых идентичностей в контексте индустриализации: нередко именно промышленные маркеры определяли путь общегородской идентификации. Третья тема охватывает изучение этничности в городских пространствах. Историки выявляют реакции этничности к процессам адаптации и аккультурации. Четвертая затрагивает исследования гендерной идентичности в контексте маскулинной направленности урбанизационных процессов. В центре внимания ученых – изучение механизмов доминирования маскулинной культуры в городской среде и раскрытие социо-культурной значимости и функций женщины, ее ограничений и процесса эмансипации. Пятая тема посвящена выявлению социальной стратификации в городских системах. Урбан-история получает новое знание в исследованиях урбанизации как факторе дифференциации городского социума и классических структур общества – сословий и классов, а также в трудах по идентификации среднего класса, социальной мобильности, формированию маргинальных групп и вернакулярной культуры. Шестая расширяется за счет работ в рамках исторической имагологии города. Образы являются формами репрезентации идентичностей в культурном и публичном дискурсах, поэтому, изучая их, урбан-история сегодня вносит практический вклад в развитие современной урбанистики. Седьмая тема фокусируется на историографическом анализе идентификационных исследовательских стратегий самих урбан-историков. Исследовательская модель выявления городских идентичностей должна базироваться на широком круге источников преимущественно нарративного характера и антропологическом подходе. Представляется целесообразным использование возможностей мемуаров, устной истории, периодики, художественной и публицистической литературы. Изучение палитры идентичностей в российской урбан-истории выходит за рамки сугубо исторической проблематики и основывается на глубоком междисциплинарном взаимодействии.Исследование поддержано грантом Российского научного фонда, проект № 20–78–10010 «Ведомственность как фактор в истории освоения Российского Севера (1930–1980-е гг.): регионализм, конфликты интересов, институциональные структуры и идентификационные стратегии»

Modulation of closed−state inactivation in Kv2.1/Kv6.4 heterotetramers as mechanism for 4−AP induced potentiation

The voltage-gated K+ (Kv) channel subunits Kv2.1 and Kv2.2 are expressed in almost every tissue. The diversity of Kv2 current is increased by interacting with the electrically silent Kv (KvS) subunits Kv5-Kv6 and Kv8-Kv9, into functional heterotetrameric Kv2/KvS channels. These Kv2/KvS channels possess unique biophysical properties and display a more tissue-specific expression pattern, making them more desirable pharmacological and therapeutic targets. However, little is known about the pharmacological properties of these heterotetrameric complexes. We demonstrate that Kv5.1, Kv8.1 and Kv9.3 currents were inhibited differently by the channel blocker 4 -aminopyridine (4-AP) compared to Kv2.1 homotetramers. In contrast, Kv6.4 currents were potentiated by 4-AP while displayingmoderately increased affinities for the channel pore blockers quinidine and flecainide. We found that the 4-AP induced potentiation of Kv6.4 currents was caused bymodulation of the Kv6.4-mediated closed-state inactivation: suppression by 4-AP of the Kv2.1/Kv6.4 closed-state inactivation recovered a population of Kv2.1/Kv6.4 channels that was inactivated at resting conditions, i.e. at a holding potential of -80 mV. This modulation also resulted in a slower initiation and faster recovery from closed-state inactivation. Using chimeric substitutions between Kv6.4 and Kv9.3 subunits, we demonstrated that the lower half of the S6 domain (S6c) plays a crucial role in the 4-AP induced potentiation. These results demonstrate that KvS subunits modify the pharmacological response of Kv2 subunits when assembled in heterotetramers and illustrate the potential of KvS subunits to provide unique pharmacological properties to the heterotetramers, as is the case for 4-AP on Kv2.1/Kv6.4 channels

The anticonvulsant retigabine suppresses neuronal Kv2-mediated currents

Enhancement of neuronal M-currents, generated through K(V)7.2-K(V)7.5 channels, has gained much interest for its potential in developing treatments for hyperexcitability-related disorders such as epilepsy. Retigabine, a K(V)7 channel opener, has proven to be an effective anticonvulsant and has recently also gained attention due to its neuroprotective properties. In the present study, we found that the auxiliary KCNE2 subunit reduced the K(V)7.2-K(V)7.3 retigabine sensitivity approximately 5-fold. In addition, using both mammalian expression systems and cultured hippocampal neurons we determined that low μM retigabine concentrations had ‘off-target’ effects on K(V)2.1 channels which have recently been implicated in apoptosis. Clinical retigabine concentrations (0.3–3 μM) inhibited K(V)2.1 channel function upon prolonged exposure. The suppression of the K(V)2.1 conductance was only partially reversible. Our results identified K(V)2.1 as a new molecular target for retigabine, thus giving a potential explanation for retigabine’s neuroprotective properties

Composition and formation of the sleeve enveloping a central venous catheter

AbstractPurpose:After catheterization, 42% to 100% of central venous catheters are surrounded by a “fibrin sleeve.” This sleeve has been considered the cause of catheter-related infections, withdrawal occlusion, and pulmonary embolism. The reactions between the vein wall and the catheter were studied. Methods: A silicone catheter was placed in the anterior caval vein of 123 rats. After in situ fixation at scheduled intervals, the pathologic changes were studied on semi-serial histologic sections by means of light microscopy, transmission electron microscopy, and scanning electron microscopy (SEM). In 36 rats, the catheter was withdrawn immediately; in 72 rats, it was left in situ up to 6 months; and in 15 rats, the study was performed up to 10 months after withdrawal of a catheter that had remained in situ for 6 months. Results: In the group in which the catheter was withdrawn immediately, mural thrombi disappeared by day 7. In the group in which the catheter remained in situ, thrombi remained around the proximal portion of the catheter. This pericatheter thrombosis (PCT) was invaded by migrating and proliferating smooth muscle cells (SMCs), originating from an injured vein wall, and transformed from day 7 into a tissue composed predominantly of SMCs and collagen and covered by endothelial cells. Later, the number of cells decreased, and the relative amount of collagen increased. Up to 10 months after withdrawal of the catheter, the collapsed sleeve was still present within the vein. Conclusion: The sleeve around a central venous catheter is not a fibrin sleeve, but a stable cellular-collagen tissue covered by endothelium. It is mainly formed by smooth muscle cells migrating from the injured vein wall into the early pericatheter thrombus. (J Vasc Surg 1998;28:260-271.

An approach to fulfill art 8 of directive 2009/128: procedure of risk assessment for pesticide application equipment

The EU Directive 2009/128/EC on the sustainable use of pesticides requires that Member States (MS) shall ensure that all Pesticide Application Equipment (PAE) in professional use shall be subject to inspection at regular intervals. Article 8.3 of the Directive allows the MS to derogate from the mandatory inspection at regular intervals or to apply different timetables and inspection intervals for certain types of PAE based on a Risk Assessment (RA) for human health, food safety and environment and an assessment of the scale of use. In order to fulfill Article 8.3, a risk assessment protocol was developed in Belgium within the framework of the SIRA-APESTICON project. Risk is now evaluated for the human health and the environment on all Belgian equipment. It will offer guidelines about the necessity to carry out an inspection of every PAE in use. The protocol is based on technical parameters subject to inspections, their occurrences and severities, but also on national scale of use of the PAE types. Results are expressed at different scale levels: the defect, the machine and the country.The EU Directive 2009/128/EC on the sustainable use of pesticides requires that Member States (MS) shall ensure that all Pesticide Application Equipment (PAE) in professional use shall be subject to inspection at regular intervals. Article 8.3 of the Directive allows the MS to derogate from the mandatory inspection at regular intervals or to apply different timetables and inspection intervals for certain types of PAE based on a Risk Assessment (RA) for human health, food safety and environment and an assessment of the scale of use. In order to fulfill Article 8.3, a risk assessment protocol was developed in Belgium within the framework of the SIRA-APESTICON project. Risk is now evaluated for the human health and the environment on all Belgian equipment. It will offer guidelines about the necessity to carry out an inspection of every PAE in use. The protocol is based on technical parameters subject to inspections, their occurrences and severities, but also on national scale of use of the PAE types. Results are expressed at different scale levels: the defect, the machine and the country

Massive Black Hole Binary Inspirals: Results from the LISA Parameter Estimation Taskforce

The LISA Parameter Estimation (LISAPE) Taskforce was formed in September 2007 to provide the LISA Project with vetted codes, source distribution models, and results related to parameter estimation. The Taskforce's goal is to be able to quickly calculate the impact of any mission design changes on LISA's science capabilities, based on reasonable estimates of the distribution of astrophysical sources in the universe. This paper describes our Taskforce's work on massive black-hole binaries (MBHBs). Given present uncertainties in the formation history of MBHBs, we adopt four different population models, based on (i) whether the initial black-hole seeds are small or large, and (ii) whether accretion is efficient or inefficient at spinning up the holes. We compare four largely independent codes for calculating LISA's parameter-estimation capabilities. All codes are based on the Fisher-matrix approximation, but in the past they used somewhat different signal models, source parametrizations and noise curves. We show that once these differences are removed, the four codes give results in extremely close agreement with each other. Using a code that includes both spin precession and higher harmonics in the gravitational-wave signal, we carry out Monte Carlo simulations and determine the number of events that can be detected and accurately localized in our four population models.Comment: 14 pages, 2 figures, 5 tables, minor changes to match version to be published in the proceedings of the 7th LISA Symposium. For more information see the Taskforce's wiki at http://www.tapir.caltech.edu/dokuwiki/lisape:hom

Prevention of catheter lumen occlusion with rT-PA versus heparin (Pre-CLOT): study protocol of a randomized trial [ISRCTN35253449]

BACKGROUND: Many patients with end-stage renal disease use a central venous catheter for hemodialysis access. A large majority of these catheters malfunction within one year of insertion, with up to two-thirds due to thrombosis. The optimal solution for locking the catheter between hemodialysis sessions, to decrease the risk of thrombosis and catheter malfunction, is unknown. The Prevention of Catheter Lumen Occlusion with rt-PA versus Heparin (PreCLOT) study will determine if use of weekly rt-PA, compared to regular heparin, as a catheter locking solution, will decrease the risk of catheter malfunction. METHODS/DESIGN: The study population will consist of patients requiring chronic hemodialysis thrice weekly who are dialyzed with a newly inserted permanent dual-lumen central venous catheter. Patients randomized to the treatment arm will receive rt-PA 1 mg per lumen once per week, with heparin 5,000 units per ml as a catheter locking solution for the remaining two sessions. Patients randomized to the control arm will receive heparin 5,000 units per ml as a catheter locking solution after each dialysis session. The study treatment period will be six months, with 340 patients to be recruited from 14 sites across Canada. The primary outcome will be catheter malfunction, based on mean blood flow parameters while on hemodialysis, with a secondary outcome of catheter-related bacteremia. A cost-effectiveness analysis will be undertaken to assess the cost of maintaining a catheter using rt-PA as a locking solution, compared to the use of heparin. DISCUSSION: Results from this study will determine if use of weekly rt-PA, compared to heparin, will decrease catheter malfunction, as well as assess the cost-effectiveness of these locking solutions