Closer to the native state. Critical evaluation of cryo-techniques for Transmission Electron Microscopy: preparation of biological samples

Over the years Transmission Electron Microscopy (TEM) has evolved into a powerful technique for the structural analysis of cells and tissues at various levels of resolution. However, optimal sample preservation is required to achieve results consistent with reality. During the last few decades, conventional preparation methods have provided most of the knowledge about the ultrastructure of organelles, cells and tissues. Nevertheless, some artefacts can be introduced at all stagesofstandard electron microscopy preparation technique. Instead, rapid freezing techniques preserve biological specimens as close as possible to the native state. Our review focuses on different cryo-preparation approaches, starting from vitrification methods dependent on sample size. Afterwards, we discuss Cryo-Electron Microscopy Of VItreous Sections (CEMOVIS) and the main difficulties associated with this technique. Cryo-Focused Ion Beam (cryo-FIB) is described as a potential alternative for CEMOVIS. Another post-processing route for vitrified samples is freeze substitution and embedding in resin for structural analysis or immunolocalization analysis. Cryo-sectioning according to Tokuyasu is a technique dedicated to high efficiency immunogold labelling. Finally, we introduce hybrid techniques, which combine advantages of primary techniques originally dedicated to different approaches. Hybrid approaches permit to perform the study of difficult-to-fix samples and antigens or help optimize the sample preparation protocol for the integrated Laser and Electron Microscopy (iLEM) technique.(Folia Histochemica et Cytobiologica 2014, Vol. 52, No, 1, 1–17

NADPH Oxidases: Insights into Selected Functions and Mechanisms of Action in Cancer and Stem Cells

NADPH oxidases (NOX) are reactive oxygen species- (ROS-) generating enzymes regulating numerous redox-dependent signaling pathways. NOX are important regulators of cell differentiation, growth, and proliferation and of mechanisms, important for a wide range of processes from embryonic development, through tissue regeneration to the development and spread of cancer. In this review, we discuss the roles of NOX and NOX-derived ROS in the functioning of stem cells and cancer stem cells and in selected aspects of cancer cell physiology. Understanding the functions and complex activities of NOX is important for the application of stem cells in tissue engineering, regenerative medicine, and development of new therapies toward invasive forms of cancers

Tozpembe Masallar Üzerine Görsel Sorgulamalar

Rose-colored tales form the conceptual basis of this research as a metaphoric expression referring to the forms of reality established in the direction of power relations through social discourses. In this respect, this research, in which the linguistic-visual meaning of expression is examined in terms of social meaning relations, has been put forward on the basis of the conceptual nature of art. If we look at the process of an individual's positioning in any community from a general perspective, we can see the direct impact of some value production and management processes such as culture and politics. While the subject's life practice is shaped around the knowledge reflected from these areas, we can say that the context of social narratives that have the power to transform reality, in a sense, increases its effect on a 'purple' ground. The metaphorical approach revealed by this form of association, the metaphor production processes that exist in the inner dynamic of art, and the thoughts and approaches in which similar relations are established have been put forward. Art movements and works, in which the critical attitude has an effect on the dissolution of rigid social meanings, are included in the understanding of each period. Art movements and works, in which the critical attitude has an effect on the dissolution of rigid social meanings, are included in the understanding of each period. In addition, art practices were carried out in which different techniques were applied in connection with the theoretical framework.Tozpembe masallar, toplumsal söylemler üzerinden güç ilişkileri doğrultusunda kurulan gerçeklik biçimlerine atıfta bulunan metaforik bir ifade olarak, bu araştırmanın kavram temelini oluşturmaktadır. Bu bakımdan, ifadenin dilsel- görsel anlamının toplumsal anlam ilişkileri doğrultusunda incelendiği bu araştırma, sanatın kavramsal doğası temelinde ortaya koyulmuştur. Bireyin herhangi bir topluluk içinde konumlanma sürecine genel bir izlekten bakacak olursak, kültür, siyaset gibi bir takım değer üretme ve yönetme süreçlerinin doğrudan etkisini görebiliriz. Öznenin yaşam pratiği bu alanlardan yansıyan bilgi etrafında şekillenmekteyken, gerçeği dönüştürecek güce sahip toplumsal anlatıların bağlamı bir anlamda ‘tozpembe’ bir zeminde etkisini artırmaktadır diyebiliriz. Bu ilişkilendirme biçiminin ortaya koyduğu metaforik yaklaşım, sanatın iç dinamiğinde var olan metafor üretim süreçleri göz önünde tutularak benzer ilişkilerin kurulduğu düşünce ve yaklaşımlar ortaya koyulmuştur. Eleştirel tavrın katı toplumsal anlamların çözülmesine etkide bulunduğu sanat hareketleri ve yapıtları her dönemin kendi anlayışı içinde yer almaktadır. Bu araştırmada da, toplumsal anlam yapılanmalarının özellikle günümüz sanatında irdelendiği yaklaşım biçimleri öne çıkmaktadır. Ayrıca kuramsal çerçeveyle bağlantılı olarak farklı tekniklerin uygulandığı sanat pratikleri gerçekleştirilmiştir

Chemical probing of homopurine-homopyrimidine repeats in vivo.

Chemical probing of homopurine-homopyrimidine repeats in vivo

1990 sonrası Türkiye’de sokak hayvanları için atılan adımlar ve etkileri

Ankara : İhsan Doğramacı Bilkent Üniversitesi İktisadi, İdari ve Sosyal Bilimler Fakültesi, Tarih Bölümü, 2015.This work is a student project of the The Department of History, Faculty of Economics, Administrative and Social Sciences, İhsan Doğramacı Bilkent University.by Özer, Abdürrahim