Radiation driven chemistry in biomolecules -- is (V)UV involved in the bioactivity of argon jet plasmas?

Cold physical plasmas, especially noble gas driven plasma jets, emit considerable amounts of ultraviolet radiation (UV). Given that a noble gas channel is present, even the energetic vacuum UV can reach the treated target. The relevance of UV radiation for antimicrobial effects is generally accepted. It remains to be clarified if this radiation is relevant for other biomedical application of plasmas, e.g., in wound care or cancer remediation. In this work, the role of (vacuum) ultraviolet radiation generated by the argon plasma jet kINPen for cysteine modifications was investigated in aqueous solutions and porcine skin. To differentiate the effects of photons of different wavelength and complete plasma discharge, a micro chamber equipped with a MgF(2), Suprasil, or Borosilicate glass window was used. In liquid phase, plasma-derived VUV radiation was effective and led to the formation of cysteine oxidation products and molecule breakdown products, yielding sulfite, sulfate, and hydrogen sulfide. At the boundary layer, the impact of VUV photons led to water molecule photolysis and formation of hydroxyl radicals and hydrogen peroxide. In addition, photolytic cleavage of the weak carbon-sulfur bond initiated the formation of sulfur oxy ions. In the intact skin model, protein thiol modification was rare even if a VUV transparent MgF(2) window was used. Presumably, the plasma-derived VUV radiation played a limited role since reactions at the boundary layer are less frequent and the dense biomolecules layers block it effectively, inhibiting significant penetration. This result further emphasizes the safety of physical plasmas in biomedical applications

Circulating Prostate Tumor Cells Detected by Reverse Transcription-PCR in Men with Localized or Castration-Refractory Prostate Cancer: Concordance with CellSearch Assay and Association with Bone Metastases and with Survival

BACKGROUND: Reverse transcription-PCR (RT-PCR) assays have been used for analysis of circulating tumor cells (CTCs), but their clinical value has yet to be established. We assessed men with localized prostate cancer or castration-refractory prostate cancer (CRPC) for CTCs via real-time RT-PCR assays for KLK3 [kallikrein-related peptidase 3; i.e., prostate-specific antigen (PSA)] and KLK2 mRNAs. We also assessed the association of CTCs with disease characteristics and survival. METHODS: KLK3, KLK2, and PSCA (prostate stem cell antigen) mRNAs were measured by standardized, quantitative real-time RT-PCR assays in blood samples from 180 localized-disease patients, 76 metastatic CRPC patients, and 19 healthy volunteers. CRPC samples were also tested for CTCs by an immunomagnetic separation system (CellSearch; Veridex) approved for clinical use. RESULTS: All healthy volunteers were negative for KLK mRNAs. Results of tests for KLK3 or KLK2 mRNAs were positive (> or =80 mRNAs/mL blood) in 37 patients (49%) with CRPC but in only 15 patients (8%) with localized cancer. RT-PCR and CellSearch CTC results were strongly concordant (80%-85%) and correlated (Kendall tau, 0.60-0.68). Among CRPC patients, KLK mRNAs and CellSearch CTCs were closely associated with clinical evidence of bone metastases and with survival but were only modestly correlated with serum PSA concentrations. PSCA mRNA was detected in only 7 CRPC patients (10%) and was associated with a positive KLK mRNA status. CONCLUSIONS: Real-time RT-PCR assays of KLK mRNAs are highly concordant with CellSearch CTC results in patients with CRPC. KLK2/3-expressing CTCs are common in men with CRPC and bone metastases but are rare in patients with metastases diagnosed only in soft tissues and patients with localized cancer

Beyond the Single Story of African Realism: Narrative Embedding in Half of a Yellow Sun

This article seeks to contribute to critical readings of realism’s memetic claims by tracing the ways in which framed narration, or writing-about-writing, serve to establish reliability in Chimamanda Adichie’s seminal novel Half of a Yellow Sun. I argue that conceptions of typicality are used almost interchangeably in scholarly discussions on realism and Africanness, and that this requires a narrative framework that untangles the myriad links between them. Inserting Adichie’s now-famous concept of the ‘single story’ into this debate, I show how Africanness and realism are negotiated as two kinds of typicality that work, counterintuitively, to undercut stereotypes, and moreover, to allow realism to establish a kind of verisimilitude that is far from mimetically naïve. I start from a theoretical overview of terms such as realism, Africanness, typicality, referentiality, diegesis, and metalepsis, attempting to clarify the connections I draw between them. I then move briefly to a juxtaposition between the embedded books in Adichie’s novel and Chinua Achebe’s Things Fall Apart as an oscillation between oral and written representations. Finally, the focal point of my investigation is the diegetic layering in Half of a Yellow Sun, where I read typicality in-between orality and writing, the public and the private, and specificity and typification. &nbsp

Teacherly aesthetics: Literature and literacy in Binyavanga Wainaina’s works

In this paper I use the concept of teacherliness to explore the connections between literature and education in Binyavanga Wainaina’s memoir One Day I Will Write About This Place and his opinion pieces on education. I read Wainaina’s texts against the way the literature/literacy duality has been envisioned in historical discourses, arguing that deeper pedagogical questions were largely overlooked in the intersections between the two theoretical fields. To address this lacuna, I use Paulo Freire’s theory of Critical Pedagogy to analyze historical debates of curriculum and canonization, as well as Wainaina’s more recent engagement with the Kenyan educational system, in which questions on how to write are intertwined with thoughts on how to teach. After detailing this history of literature and literacy in East Africa, I explore the themes and aesthetic devices that Wainaina develops in One Day to reflect on his own role as an educator in the context of his troubled relationship with his own schooling. By focusing on the theme of failure and Wainaina’s embedding of oral structures into his text, I suggest Wainaina’s work offers insights and concrete narrative patterns that might become fruitful tools through which educational theory and literary analysis might illuminate each other’s blind spots, specifically in regard to oral skills in education