Silica botryoids from chemically oscillating reactions and as Precambrian environmental proxies

In this petrographic and geochemical study, we differentiated diverse quartz botryoids, including circular-concentric, twinned, columnar, wavy, and stromatolite-like structures versus synchronous biotic patterns of similar geometry and size dimensions (filamentous traits and stromatolites) in Precambrian cherts of Barberton, South Africa, and Gunflint, Canada. The botryoidal habits explored retained self-similar patterns of radially aligned acicular quartz with concentric laminae, which are not documented in biologically built stromatolites. These ancient fractals and their composition imitate those in chemically oscillating reactions, implying that the precipitation of botryoids was fueled by abiotic diagenetic degradation of organic matter and subsequently metamorphosed into chert

Arrested versus active silica diagenesis reaction boundaries—A review of seismic diagnostic criteria

This paper evaluates previously proposed diagnostic criteria that can be used to determine whether or not there is active migration of the opal-A to opal-CT transition zone (TZA/CT). The criteria are based on the interpretation of 2D and 3D seismic surveys and are therefore geometrical. They involve an assessment of the relationship of the TZA/CT with polygonal fault systems, differential compaction structures and tectonic folds. The most robust evidence for an inactive ‘reaction front’ between opal-A and opal-CT bearing sediments is the discordance of the TZA/CT relative to present-day isotherms. Any of these may be persuasive as diagnostic criteria for the upward arrest of the diagenetic transformation at a regional scale, but actual truncation of the TZA/CT at the modern seabed is definitive for arrested diagenesis. This study argues that diagenetic assessment based solely on a single criterion independently is not reliable as an indicator for the current state of a silica transition. As a conclusion, the analysed seismic/structural criteria should be synthesised to provide a more credible interpretation for silica diagenesis. The use of modern 2D and 3D seismic data for the reconstruction of the diagenetic history of opaline silica bearing sediments offers a new approach to the study of silica diagenesis at a regional scale

Холотропное дыхание как метод реализации потенциала личности сотрудника

На сегодняшний день в организациях существует множество проблем, из-за которых возникают сложности как в управлении предприятием, так и в эффективной работе сотрудников. Для любого управляющего компанией важно, чтобы сотрудник был уверенным, умеющим нестандартно мыслить, инициативным, целеустремленным, но в большинстве случаев на предприятии такие сотрудники отсутствуют или их количество ограниченно. В любом сотруднике кроется творческая личность, которая не всегда может быть реализована на практике или же просто подавлена. Для того чтобы предприятие могло эффективно функционировать, важно, чтобы каждый сотрудник мог разобраться в своих проблемах и обрести внутреннюю гармонию, которая позволит ему настроиться на работу и выполнять ее эффективно. Методика холотропного дыхания может помочь личности реализовать свой скрытый потенциал. Цель работы: определить значимость методики холотропного дыхания в организации и выявить, какое влияние она оказывает как на сотрудников, так и на предприятие в целом. Методы исследования: анализ литера- туры по данной проблематике, аналитический метод. Результаты: выводы, полученные в данном исследовании, способствуют определению действенности методики холотропного дыхания и значимости ее применения в организации. Today there are many problems in organizations which lead to difficulties in the management of an enterpriseand in the effective work of the staff. For any company manager it is important that the employee wasconfident, able to think outside the box, initiative, committed, but in most cases such employees are absent ortheir number is limited. There is creative personality in any employee which can’t always be revealed or issimply suppressed. In order for a company to operate effectively, it is important that every employee couldunderstand their problems and find inner harmony, which will allow them to tune into work and perform itefficiently. The technique of holotropic breathwork can help the person to realize their hidden potential. Objective:to determine the significance of the technique of holotropic breathwork in the organization and itsimpact on the employees and the enterprise as a whole. Methods: review of the literature on this subject,data analysis. Results. The findings of this study help to identify the effective methods of holotropic breathworkand the importance of its application in the organization

Solid-phase-assisted synthesis of targeting peptide-PEG-oligo(ethane amino)amides for receptor-mediated gene delivery.

In the forthcoming era of cancer gene therapy, efforts will be devoted to the development of new efficient and non-toxic gene delivery vectors. In this regard, the use of Fmoc/Boc-protected oligo(ethane amino)acids as building blocks for solid-phase-supported assembly represents a novel promising approach towards fully controlled syntheses of effective gene vectors. Here we report on the synthesis of defined polymers containing the following: (i) a plasmid DNA (pDNA) binding domain of eight succinoyl-tetraethylenpentamine (Stp) units and two terminal cysteine residues; (ii) a central polyethylene glycol (PEG) chain (with twenty-four oxyethylene units) for shielding; and (iii) specific peptides for targeting towards cancer cells. Peptides B6 and c(RGDfK), which bind transferrin receptor and αvβ3 integrin, respectively, were chosen because of the high expression of these receptors in many tumoral cells. This study shows the feasibility of designing these kinds of fully controlled vectors and their success for targeted pDNA-based gene transfer

Современные методы анализа и оценки риска

В статье проведен анализ методов оценки риска, рассмотрена их классификация. Представлен краткий обзор современных методов анализ риска и выявлены наиболее эффективные

Insight into the relationship between the cell culture model, cell trafficking and siRNA silencing efficiency

Despite research efforts, cell uptake processes determining siRNA silencing efficiency remain unclear. Here, we examine the relationship between in vitro cell culture models, cellular trafficking and siRNA silencing efficiency to provide a mechanistic insight on siRNA delivery system design. Model siRNA-polyplexes, based on chitosan as a ‘classical’ condensing agent, were applied to a panel of lung epithelial cell lines, H1299, A549 and Calu-3 and cell internalization levels, trafficking pathways and gene silencing assessed on exposure to pharmacological inhibitors. The data reveal striking differences in the internalization behaviour and gene silencing efficiency in the tested cell lines, despite their common lung epithelial origins. The model system’s silencing was lower where clathrin internalization pathway predominated in Calu-3, relative to silencing in H1299 cells where a non-clathrin internalization appears dominant. Increased silencing on endosomal disruption was apparent in Calu-3 cells, but absent when cellular internalization was not predominantly clathrin-mediated in A549 cells. This highlights that identifying cell trafficking pathways before incorporation of functional components to siRNA delivery systems (e.g. endosomolytic compounds) is crucial. The study hence stresses the importance of selection of appropriate cell culture model, relevant to in vivo target, to assess the gene silencing efficiency and decide which functionalities the ‘stratified siRNA silencing vector’ requires

Chitosan and its derivatives as nanocarriers for siRNA delivery

The ability to specifically silence genes using siRNA has enormous potential for treating genetic diseases. However, siRNA instability and biodistribution issues still need to be overcome, and adequate delivery vehicles have proven indispensable in conveying siRNA to its target. Chitosan is a promising biopolymer for siRNA delivery, its interest stemming from its safety, biodegradability, mucoadhesivity, permeation enhancing effect and cationic charge, as well as amenability to undergo chemical modifications. Chitosan and its derivatives can be readily arranged into complexes or nanoparticles able to entrap and carry siRNA. Specific strategies have been adopted to improve chitosan-based vectors with regard to transfectability. However, further efforts are required to verify their value and adapt them to enhance therapeutic output prior to clinical application. This review emphasizes the potential of chitosan and its derivatives to develop nanocarriers for siRNA delivery. The properties of chitosan that are significant for transfectability and the most relevant findings are assessed