137 research outputs found
Hierarchical Porous Polybenzimidazole Microsieves: An Efficient Architecture for Anhydrous Proton Transport via Polyionic Liquids
Liquid-induced phase-separation micromolding (LIPSΒ΅M) has been successfully used for manufacturing hierarchical porous polybenzimidazole (HPBI) microsieves (42-46% porosity, 30-40 Β΅m thick) with a specific pore architecture (pattern of macropores: ~9 Β΅m in size, perforated, dispersed in a porous matrix with a 50-100 nm pore size). Using these microsieves, proton-exchange membranes were fabricated by the infiltration of a 1H-3-vinylimidazolium bis(trifluoromethanesulfonyl)imide liquid and divinylbenzene (as a cross-linker), followed by in situ UV polymerization. Our approach relies on the separation of the ion conducting function from the structural support function. Thus, the polymeric ionic liquid (PIL) moiety plays the role of a proton conductor, whereas the HPBI microsieve ensures the mechanical resistance of the system. The influence of the porous support architecture on both proton transport performance and mechanical strength has been specifically investigated by means of comparison with straight macroporous (36% porosity) and randomly nanoporous (68% porosity) PBI counterparts. The most attractive results were obtained with the poly[1-(3H-imidazolium)ethylene]bis(trifluoromethanesulfonyl)imide PIL cross-linked with 1% divinylbenzene supported on HPBI membranes with a 21-Β΅m-thick skin layer, achieving conductivity values up to 85 mS cm-1 at 200 Β°C under anhydrous conditions and in the absence of mineral acids
Bardet-Biedl Syndrome ciliopathy is linked to altered hematopoiesis and dysregulated self-tolerance
BardetβBiedl Syndrome (BBS) is a pleiotropic genetic disease caused by the dysfunction of primary cilia. The immune system of patients with ciliopathies has not been investigated. However, there are multiple indications that the impairment of the processes typically associated with cilia may have influence on the hematopoietic compartment and immunity. In this study, we analyze clinical data of BBS patients and corresponding mouse models carrying mutations in Bbs4 or Bbs18. We find that BBS patients have a higher prevalence of certain autoimmune diseases. Both BBS patients and animal models have altered red blood cell and platelet compartments, as well as elevated white blood cell levels. Some of the hematopoietic system alterations are associated with BBSβinduced obesity. Moreover, we observe that the development and homeostasis of B cells in mice is regulated by the transport complex BBSome, whose dysfunction is a common cause of BBS. The BBSome limits canonical WNT signaling and increases CXCL12 levels in bone marrow stromal cells. Taken together, our study reveals a connection between a ciliopathy and dysregulated immune and hematopoietic systems
ΠΡΠΈΠ·ΠΈΡ ΡΠΊΠΎΠ½ΠΎΠΌΠΈΠΊΠΈ ΡΠΎΡΡΠ° ΠΊΠ°ΠΊ ΡΠΈΡΡΠ΅ΠΌΡ: ΠΏΡΠΈΡΠΈΠ½Ρ ΠΈ ΡΠ»Π΅Π΄ΡΡΠ²ΠΈΡ
ΠΠΊΡΡΠ°Π»ΡΠ½ΠΎΡΡΡ Π΄Π°Π½Π½ΠΎΠΉ ΡΠ°Π±ΠΎΡΡ ΠΏΡΠΎΠ΄ΠΈΠΊΡΠΎΠ²Π°Π½Π° ΠΊΡΠΈΠ·ΠΈΡΠ½ΡΠΌ ΡΠΎΡΡΠΎΡΠ½ΠΈΠ΅ΠΌ ΡΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΠΎΠΉ ΠΌΠΎΠ΄Π΅Π»ΠΈ ΡΠΊΠΎΠ½ΠΎΠΌΠΈΠΊΠΈ. Π ΠΎΡΠ½ΠΎΠ²Π΅ ΡΡΠΎΠΉ ΠΌΠΎΠ΄Π΅Π»ΠΈ Π»Π΅ΠΆΠ°Ρ ΠΏΠΎΡΡΡΠ»Π°ΡΡ ΠΎ Π½Π΅ΠΎΠ±Ρ
ΠΎΠ΄ΠΈΠΌΠΎΡΡΠΈ ΠΏΠΎΡΡΠΎΡΠ½Π½ΠΎΠ³ΠΎ ΡΠΎΡΡΠ° ΡΠΊΠΎΠ½ΠΎΠΌΠΈΠΊΠΈ, ΠΊΠΎΡΠΎΡΡΠΉ ΠΎΠ±Π΅ΡΠΏΠ΅ΡΠΈΠ²Π°Π΅ΡΡΡ Π·Π° ΡΡΠ΅Ρ ΠΊΠΎΠ½Π΅ΡΠ½ΠΎΠ³ΠΎ ΠΏΠΎΡΡΠ΅Π±Π»Π΅Π½ΠΈΡ. Π ΠΎΠ±Π΅ΡΠΏΠ΅ΡΠ΅Π½ΠΈΠ΅ ΠΆΠ΅ ΡΠ΅Π°Π»ΠΈΠ·Π°ΡΠΈΠΈ ΡΠ°ΠΊΠΎΠΉ ΠΌΠΎΠ΄Π΅Π»ΠΈ ΠΏΠΎΠ»ΠΎΠΆΠ΅Π½Ρ ΠΌΠΎΠ½Π΅ΡΠ°ΡΠ½ΡΠ΅ ΠΏΠΎΠ΄Ρ
ΠΎΠ΄Ρ ΠΈ ΠΌΠ΅ΡΠΎΠ΄Ρ ΡΡΠΈΠΌΡΠ»ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΏΠΎΡΡΠ΅Π±ΠΈΡΠ΅Π»ΡΡΠΊΠΎΠ³ΠΎ ΡΠΏΡΠΎΡΠ° ΠΊΠ°ΠΊ ΠΎΡΠ½ΠΎΠ²Π½ΠΎΠ³ΠΎ Π΄ΡΠ°ΠΉΠ²Π΅ΡΠ° ΡΠΊΠΎΠ½ΠΎΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΡΠΎΡΡΠ°. ΠΠ΅Π½ΡΠΎΠΌ Π΄Π°Π½Π½ΠΎΠΉ ΠΌΠΎΠ΄Π΅Π»ΠΈ ΡΡΠ°Π»Π° Π΄ΠΎΠ»Π³ΠΎΠ²Π°Ρ ΡΠΊΠΎΠ½ΠΎΠΌΠΈΠΊΠ° ΠΏΠΎΡΡΠ΅Π±Π»Π΅Π½ΠΈΡ ΠΎΠ±ΡΠ΅ΡΡΠ² ΠΈΠ½Π΄ΠΈΠ²ΠΈΠ΄ΡΠ°Π»ΠΈΡΡΠΎΠ², Π½Π΅ ΠΈΠΌΠ΅ΡΡΠΈΡ
ΡΠΈΡΡΠ΅ΠΌΡ ΡΡΠ°Π΄ΠΈΡΠΈΠΎΠ½Π½ΡΡ
ΡΠ΅Π½Π½ΠΎΡΡΠ΅ΠΉ, Π° ΠΎΡΠΈΠ΅Π½ΡΠΈΡΡΡΡΠΈΡ
ΡΡ Π½Π° ΠΈΠ»Π»ΡΠ·ΠΎΡΠ½ΡΠ΅ Π²ΡΠ΅ΠΌΠ΅Π½Π½ΡΠ΅ ΡΠ΅Π»ΠΈ ΠΊΡΠ°ΡΠΊΠΎΡΡΠΎΡΠ½ΠΎΠ³ΠΎ ΠΏΠ΅ΡΠΈΠΎΠ΄Π°. Π’Π°ΠΊ, ΡΠ³ΠΎΡΠ΅Π½ΡΡΠΈΡΠ΅ΡΠΊΠ°Ρ ΠΌΠΎΠ΄Π΅Π»Ρ ΡΠΊΠΎΠ½ΠΎΠΌΠΈΠΊΠΈ Π·Π°Π½ΡΠ»Π° Π³Π»Π°Π²Π΅Π½ΡΡΠ²ΡΡΡΠ΅Π΅ ΠΏΠΎΠ»ΠΎΠΆΠ΅Π½ΠΈΠ΅ ΠΏΠΎ ΠΎΡΠ½ΠΎΡΠ΅Π½ΠΈΡ ΠΊ ΡΠΊΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΌΠΎΠ΄Π΅Π»ΠΈ ΡΠΊΠΎΠ½ΠΎΠΌΠΈΠΊΠΈ, ΠΎΠ±Π½Π°ΠΆΠΈΠ² ΠΌΠ°ΡΡΡ ΡΠΈΡΡΠ΅ΠΌΠΎΠΎΠ±ΡΠ°Π·ΡΡΡΠΈΡ
ΠΏΡΠΎΡΠΈΠ²ΠΎΡΠ΅ΡΠΈΠΉ. ΠΡΠ΄ΡΡΠ΅Π΅ ΠΎΠΊΠ°Π·Π°Π»ΠΎΡΡ ΠΏΠΎΠ΄ ΡΠ³ΡΠΎΠ·ΠΎΠΉβ¦ Π¦Π΅Π»ΡΡ Π΄Π°Π½Π½ΠΎΠΉ ΡΠ°Π±ΠΎΡΡ ΡΠ²Π»ΡΠ΅ΡΡΡ Π°Π½Π°Π»ΠΈΠ· ΠΈΡΡ
ΠΎΠ΄Π½ΡΡ
ΠΏΡΠΈΡΠΈΠ½ ΡΡΠΈΡ
ΠΏΡΠΎΡΠΈΠ²ΠΎΡΠ΅ΡΠΈΠΉ, ΡΠ°ΠΊΡΠΎΡΠΎΠ² Π²ΠΎΠ·Π½ΠΈΠΊΠ½ΠΎΠ²Π΅Π½ΠΈΡ ΠΊΡΠΈΠ·ΠΈΡΠ½ΡΡ
ΡΠ²Π»Π΅Π½ΠΈΠΉ ΠΈ ΡΠ³ΡΠΎΠ·, Ρ ΠΊΠΎΡΠΎΡΡΠΌΠΈ ΡΡΠΎΠ»ΠΊΠ½ΡΠ»ΠΎΡΡ ΡΠ΅Π»ΠΎΠ²Π΅ΡΠ΅ΡΡΠ²ΠΎ Π½Π° ΡΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΠΎΠΌ ΡΡΠ°ΠΏΠ΅ ΡΠ°Π·Π²ΠΈΡΠΈΡ, Π° ΡΠ°ΠΊΠΆΠ΅ Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΡΡ
Π°Π»ΡΡΠ΅ΡΠ½Π°ΡΠΈΠ² ΡΡΡΡΠ°Π½Π΅Π½ΠΈΡ ΡΡΠΈΡ
ΠΏΡΠΎΡΠΈΠ²ΠΎΡΠ΅ΡΠΈΠΉ ΠΈ ΡΠ³ΡΠΎΠ·. The relevance of this work is dictated by a critical state of the modern model of the economy. The basis of this model is construed by postulates about the need for sustained economic growth, which is provided by end-use. Monetary approaches and methods of consumer demand stimulation as a main incentive of economic growth guarantee the model implementation. On the top of this model there is a debt consumer economy of a society of individualists who do not have a system of traditional values, but instead have illusory short-term goals. Thus, an egocentric model of the economy has taken a dominant position in relation to an ecological economic model, revealing a lot of systemic contradictions. The future was under threat... The aim of this work is the analysis of the causes of these conflicts, the factors of crisis phenomena, the threats, which mankind faced at this stage of development, and the possible ways of elimination of the contradictions and threats as well. Methods: comparative analysis and synthesis of theoretical fundamental economic sources and assumptions, practical research and personal experience of various Russian and foreign scientists and business practitioners, the results, observations and conclusions arising from the personal experience of the author and his own theoretical research and inventions, and analysis of statistical data
Spectroscopic survey of Kepler stars. I. HERMES/Mercator observations of A- and F-type stars
The Kepler space mission provided near-continuous and high-precision photometry of about 207 000 stars, which can be used for asteroseismology. However, for successful seismic modeling it is equally important to have accurate stellar physical parameters. Therefore, supplementary ground-based data are needed. We report the results of the analysis of high-resolution spectroscopic data of A- and F-type stars from the Kepler field, which were obtained with the HERMES spectrograph on the Mercator telescope. We determined spectral types, atmospheric parameters and chemical abundances for a sample of 117 stars. Hydrogen Balmer, Feβi, and Feβii lines were used to derive effective temperatures, surface gravities, and microturbulent velocities. We determined chemical abundances and projected rotational velocities using a spectrum synthesis technique. The atmospheric parameters obtained were compared with those from the Kepler Input Catalogue (KIC), confirming that the KIC effective temperatures are underestimated for A stars. Effective temperatures calculated by spectral energy distribution fitting are in good agreement with those determined from the spectral line analysis. The analysed sample comprises stars with approximately solar chemical abundances, as well as chemically peculiar stars of the Am, Ap, and Ξ» Boo types. The distribution of the projected rotational velocity, vsinβi, is typical for A and F stars and ranges from 8 to about 280 km sβ1, with a mean of 134 km sβ1
Spectroscopic survey of Kepler stars. I. HERMES/Mercator observations of A- and F-type stars
The Kepler space mission provided near-continuous and high-precision photometry of about 207000 stars, which can be used for asteroseismology. However, for successful seismic modeling it is equally important to have accurate stellar physical parameters. Therefore, supplementary ground-based data are needed. We report the results of the analysis of high-resolution spectroscopic data of A- and F-type stars from the Kepler field, which were obtained with the HERMES spectrograph on the Mercator telescope. We determined spectral types, atmospheric parameters and chemical abundances for a sample of 117 stars. Hydrogen Balmer, Feβi, and Feβii lines were used to derive effective temperatures, surface gravities, and microturbulent velocities. We determined chemical abundances and projected rotational velocities using a spectrum synthesis technique. The atmospheric parameters obtained were compared with those from the Kepler Input Catalogue (KIC), confirming that the KIC effective temperatures are underestimated for A stars. Effective temperatures calculated by spectral energy distribution fitting are in good agreement with those determined from the spectral line analysis. The analysed sample comprises stars with approximately solar chemical abundances, as well as chemically peculiar stars of the Am, Ap, and Ξ»Boo types. The distribution of the projected rotational velocity, vsinβi, is typical for A and F stars and ranges from 8 to about 280kmsβ1, with a mean of 134kmsβ
Skin tribology: Science friction?
The application of tribological knowledge is not just restricted to optimizing mechanical and chemical engineering problems. In fact, effective solutions to friction and wear related questions can be found in our everyday life. An important part is related to skin tribology, as the human skin is frequently one of the interacting surfaces in relative motion. People seem to solve these problems related to skin friction based upon a trial-and-error strategy and based upon on our sense for touch. The question of course rises whether or not a trained tribologist would make different choices based upon a science based strategy? In other words: Is skin friction part of the larger knowledge base that has been generated during the last decades by tribology research groups and which could be referred to as Science Friction? This paper discusses the specific nature of tribological systems that include the human skin and argues that the living nature of skin limits the use of conventional methods. Skin tribology requires in vivo, subject and anatomical location specific test methods. Current predictive friction models can only partially be applied to predict in vivo skin friction. The reason for this is found in limited understanding of the contact mechanics at the asperity level of product-skin interactions. A recently developed model gives the building blocks for enhanced understanding of friction at the micro scale. Only largely simplified power law based equations are currently available as general engineering tools. Finally, the need for friction control is illustrated by elaborating on the role of skin friction on discomfort and comfort. Surface texturing and polymer brush coatings are promising directions as they provide way and means to tailor friction in sliding contacts without the need of major changes to the produc
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