124 research outputs found

    Formation of self-organized organic-inorganic hybrids

    No full text
    The morphology features and peculiarities of current-voltage characteristics of selforganized organic–silicon hybrids were investigated. The organic layers were formed by chemical bath deposition at room temperatures of phosphorus doped n-type FZ Si-patterned substrate. The pattern was formed by etching in anisotropic etch on the base of aqueous solution of potassium hydrate KOH and isopropyl alcohol. The following aqueous solutions of organic heterocyclic aromatic compounds were used for hybrids formation: sulfacyl sodium, procainamide hydrochloride (novocain) and lamotridgine. These hybrids have shown different types of morphology. This depends on substrate properties, time deposition and organic concentration in water solution. The photovoltaic effect of organic-pattern silicon is the result of chemisorptions of functional amine, amide, carboxyl, thiols and halogen groups on silicon pattern-type surface. At the same time these results have proven that the substrate of start and classic morphology in pyramid form is favored for formation of organic-silicon hybrids for photovoltaic application.Досліджено морфологічні властивості та особливості характеристик струм–напруга для самоорганізованих кремнійорганічних гібридів. Органічні шари було одержано хімічним осадженням за кімнатної температури легованих фосфором візерункових кремнієвих субстратів FZ n-типу. Візерунок формували витравлюванням в анізотропних травниках на основі водного розчину гідрату калію КОН та ізопропилового спирту. В подальшому для отримання гібридів використовували водні розчини органічних гетероциклічних сполук: сульфосаліцилового натрію, гідро хлориду прокаінаміду (новокаїну) і ламотріджину. Ці гібриди показали різну морфологію. Вона залежить від властивостей субстрату, часу осадження та концентрації органічної складової у водних розчинах. Фотогальванічний ефект кремнійорганічного рисунка є результатом хемосорбції функціональних груп амінів, амідів, карбоксилу, тріолів та галогену на поверхні кремнію. Водночас, ці результати підтверджують,що субстрат початкової і класичної морфології у вигляді піраміди кращий для утворення кремнійорганічних гібридів фотогальванічного застосування.Исследованы морфологические свойства и особенности характеристик ток–напряжение для самоорганизующихся кремнийорганических гибридов. Органические слои были получены химическим осаждением при комнатной температуре легированных фосфором узорчатых кремниевых субстратов FZ n-типа. Узор формировали вытравливанием в анизотропных травителях на основе водного раствора гидрата калия KOH и изопропилового спирта. В дальнейшем для получения гибридов использовали водные растворы органических гетероциклических соединений: сульфосалицилового натрия, гидрохлорида прокаинамида (новокаина) и ламотритриджина. Эти гибриды показали различную морфологию. Она зависит от свойств субстрата, времени осаждения и концентрации органической составляющей в водных растворах. Фотогальванический эффект кремнийорганического рисунка является результатом хемосорбции функциональных групп аминов, амидов, карбоксила, триолов и галогена на поверхности кремния. В то же самое время, эти результаты подтверждают, что субстрат начальной и классической морфологии в виде пирамиды является предпочтительным для образования кремнийорганических гибридов фотогальванического применения

    Apoptosis is not conserved in plants as revealed by critical examination of a model for plant apoptosis-like cell death

    Get PDF
    Background: Animals and plants diverged over one billion years ago and evolved unique mechanisms for many cellular processes, including cell death. One of the most well-studied cell death programmes in animals, apoptosis, involves gradual cell dismantling and engulfment of cellular fragments, apoptotic bodies, through phagocytosis. However, rigid cell walls prevent plant cell fragmentation and thus apoptosis is not applicable for executing cell death in plants. Furthermore, plants are devoid of the key components of apoptotic machinery, including phagocytosis as well as caspases and Bcl-2 family proteins. Nevertheless, the concept of plant "apoptosis-like programmed cell death" (AL-PCD) is widespread. This is largely due to superficial morphological resemblances between plant cell death and apoptosis, and in particular between protoplast shrinkage in plant cells killed by various stimuli and animal cell volume decrease preceding fragmentation into apoptotic bodies.Results: Here, we provide a comprehensive spatio-temporal analysis of cytological and biochemical events occurring in plant cells subjected to heat shock at 40-55 degrees C and 85 degrees C, the experimental conditions typically used to trigger AL-PCD and necrotic cell death, respectively. We show that cell death under both conditions was not accompanied by membrane blebbing or formation of apoptotic bodies, as would be expected during apoptosis. Instead, we observed instant and irreversible permeabilization of the plasma membrane and ATP depletion. These processes did not depend on mitochondrial functionality or the presence of Ca2+ and could not be prevented by an inhibitor of ferroptosis. We further reveal that the lack of protoplast shrinkage at 85 degrees C, the only striking morphological difference between cell deaths induced by 40-55 degrees C or 85 degrees C heat shock, is a consequence of the fixative effect of the high temperature on intracellular contents.Conclusions: We conclude that heat shock-induced cell death is an energy-independent process best matching definition of necrosis. Although the initial steps of this necrotic cell death could be genetically regulated, classifying it as apoptosis or AL-PCD is a terminological misnomer. Our work supports the viewpoint that apoptosis is not conserved across animal and plant kingdoms and demonstrates the importance of focusing on plant-specific aspects of cell death pathways

    1,4-bis(2,2-diphenylethenyl)benzene as an efficient emitting material for organic light emitting diodes

    No full text
    We report on the photophysical properties of 1,4-bis(2,2-diphenylethenyl)benzene (PEB) in a solution and a solid state. A poor blue photoluminescence efficiency of PEB in a solution dramatically increases in the deposited film. We explain such properties in terms of molecular dynamics and degrees of intramolecular freedom in various molecular environments. PEB as an electron-transport and emitting layer in organic light-emitting diodes (OLEDs) shows bright blue-green electroluminescence (EL) with the peak wavelength at λmax ~ 495 nm. The maximum external EL quantum efficiency of ηEL = 2.5 % and maximum luminance of 41600 cd/m2 in the optimized device were obtained, indicating that PEB possesses superior electron-transport ability

    Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

    Get PDF

    Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

    Get PDF
    In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field
    corecore