Self-sustained oscillations within the temperature hysteresis in CO oxidation over Pd: Mathematical model of a cascade of continuous stirred-tank reactors

The results of temperature-programmed reaction experimental studies and mathematical modeling of self-sustained oscillations within an inverse temperature hysteresis in CO oxidation over Pd catalyst are presented. The experimental data demonstrate the influence of the reaction medium on the catalyst activity under reaction conditions. Under oxygen excess in the feeding gas mixture and high temperature, the defects appeared on the initially flat surface of metallic palladium due to deep oxidation of palladium (three-dimensional PdO nanoparticles were observed). The palladium oxide reduced under cooling of the catalytic system, and the catalyst surface became flat again. To take into account these variations of the palladium surface structure, we consider the piecewise-constant dependence of the rate constant of some reaction step on the concentrations of oxygen species, namely, the dissolved oxygen or oxide in the palladium bulk. The proposed model of the process in the cascade of continuous stirred-tank reactors that account for these dependences qualitatively describes the inverse temperature hysteresis as well as the oscillatory dynamics within the hysteresis loop which were obtained experimentally.     

Plasma‐Activated Substrate with a Tropoelastin Anchor for the Maintenance and Delivery of Multipotent Adult Progenitor Cells

Conventional wound therapy utilizes wound coverage to prevent infection, trauma, and fluid and thermal loss. However, this approach is often inadequate for large and/or chronic wounds, which require active intervention via therapeutic cells to promote healing. To address this need, a patch which delivers multipotent adult progenitor cells (MAPCs) is developed. Medical‐grade polyurethane (PU) films are modified using plasma immersion ion implantation (PIII), which creates a radical‐rich layer capable of rapidly and covalently attaching biomolecules. It is demonstrated that a short treatment duration of 400 s maximizes surface activation and wettability, minimizes reduction in gas permeability, and preserves the hydrolytic resistance of the PU film. The reactivity of PIII‐treated PU is utilized to immobilize the extracellular matrix protein tropoelastin in a functional conformation that stably withstands medical‐grade ethylene oxide sterilization. The PIII‐treated tropoelastin‐functionalized patch significantly promotes MAPC adhesion and proliferation over standard PU, while fully maintaining cell phenotype. Topical application of the MAPC‐seeded patch transfers cells to a human skin model, while undelivered MAPCs repopulate the patch surface for subsequent cell transfer. The potential of this new wound patch as a reservoir for the sustained delivery of therapeutic MAPCs and cell‐secreted factors for large and/or non‐healing wounds is indicated in the findings.     

Tin,Titanium, Tantalum,Vanadium and Niobium Oxide Based Sensors to Detect Colorectal Cancer Exhalations in Blood Samples

User-friendly, low-cost equipment for preventive screening of severe or deadly pathologies are one of the most sought devices by the National Health Services, as they allow early disease detection and treatment, often avoiding its degeneration. In recent years more and more research groups are developing devices aimed at these goals employing gas sensors. Here, nanostructured chemoresistive metal oxide (MOX) sensors were employed in a patented prototype aimed to detect volatile organic compounds (VOCs), exhaled by blood samples collected from patients affected by colorectal cancer and from healthy subjects as a control. Four sensors, carefully selected after many years of laboratory tests on biological samples (cultured cells, human stools, human biopsies, etc.), were based here on various percentages of tin, tungsten, titanium, niobium, tantalum and vanadium oxides. Sensor voltage responses were statistically analyzed also with the receiver operating characteristic (ROC) curves, that allowed the identification of the cut-off discriminating between healthy and tumor affected subjects for each sensor, leading to an estimate of sensitivity and specificity parameters. ROC analysis demonstrated that sensors employing tin and titanium oxides decorated with gold nanoparticles gave sensitivities up to 80% yet with a specificity of 70%.     

A database for inventory of proteoform profiles: “2DE-pattern”

The human proteome is composed of a diverse and heterogeneous range of gene products/proteoforms/protein species. Because of the growing amount of information about proteoforms generated by different methods, we need a convenient approach to make an inventory of the data. Here, we present a database of proteoforms that is based on information obtained by separation of proteoforms using 2DE followed by shotgun ESI–LC–MS/MS. The database's principles and structure are described. The database is called “2DE-pattern” as it contains multiple isoform-centric patterns of proteoforms separated according to 2DE principles. The database can be freely used at http://2de-pattern.pnpi.nrcki.ru .     

Preparation,chemical features,structure and applications of membrane materials based on graphene oxide

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Enhanced electrochemical performance of MoS2 anode material with novel composite binder

Journal of Solid State Electrochemistry - A simple and green approach for creating a highly capacitive molybdenum disulphide (MoS2) anode material for lithium-ion batteries is proposed. The...     

Enumeration of lactic acid bacteria: lacuna and improvement areas highlighted by proficiency testing

Accreditation and Quality Assurance - During the 2011 to 2018 food microbiology proficiency testing (PT) schemes organized by REQUASUD, a systematic analytical issue was detected. For the...     

Synthesis of the Zn1.9Cu0.1SiO4 pigment via the sol–gel and coprecipitation methods

Journal of Sol-Gel Science and Technology - The Zn1.9Cu0.1SiO4 pigment was obtained by two variants of “soft” chemistry methods: using sol–gel synthesis in ethanol from TEOS and...     

Purification of human recombinant anti-mullerian hormone and its derivatives

Anti-mullerian hormone (AMH) is a cytokine of transforming growth factor β (TGF-β) superfamily able to induce apoptosis in cells bearing specific AMH type II receptors (AMHRII). AMHRII is overexpressed in some malignant cells, so at present recombinant AMH (rAMH) is considered as a new candidate antineoplastic drug. The use of rAMH may be especially effective in case of such severe diseases as ovarian, prostate and breast cancer. However, the development of a new drug is hampered by the laboriousness of obtaining highly purified rAMH and by the lack of data about the pharmacological characteristics of rAMH derivatives. In this work, we obtained preparations of prohormone, half-cleaved rAMH and a C-terminal fragment of rAMH, which was confirmed by qualitative and quantitative analyses. To obtain rAMH and its derivatives we used a previously developed highly effective producer strain containing the optimized human AMH gene. The production process has been divided into several stages: (a) rAMH biosynthesis in the bioreactor; (b) culture media preparation; (c) purification of rAMH and its derivatives using immunoaffinity chromatography and reversed-phase HPLC; (d) identification of the purified proteins by immunoblotting and analytical reversed-phase HPLC; and (e) evaluation of the hormone forms activity. The obtained proteins may be used in preclinical trials and in vitro study of rAMH derivatives properties.