Pathological validation and significance of micrometastasis in sentinel nodes in primary breast cancer

In embracing a multidisciplinary approach to the management of patients with sentinel node biopsy in breast cancer, the pathologist task is to screen sentinel nodes for possible metastasis. The consequences of missing sentinel node micrometastasis can directly influence treatment strategies, and this screening therefore has to be performed with more attention than usual. There is presently great diversity in the histopathological work-up of sentinel nodes, with many centres employing additional techniques such as immunohistochemistry, reverse transcription polymerase chain reaction or flow cytometry in addition to routine haematoxylin and eosin staining. In this review, we address the pathological validation and significance of micrometastasis in sentinel node biopsy in primary breast cancer

Primary dengue virus infections induce differential cytokine production in Mexican patients

Severe dengue pathogenesis is not fully understood, but high levels of proinflammatory cytokines have been associated with dengue disease severity. In this study, the cytokine levels in 171 sera from Mexican patients with primary dengue fever (DF) and dengue haemorrhagic fever (DHF) from dengue virus (DENV) 1 (n = 116) or 2 (n = 55) were compared. DF and DHF were defined according to the patient’s clinical condition, the primary infections as indicated by IgG enzymatic immunoassay negative results, and the infecting serotype as assessed by real-time reverse transcriptionpolymerase chain reaction. Samples were analysed for circulating levels of interleukin (IL)-12p70, interferon (IFN)-γ, tumour necrosis factor (TNF)-α, IL-6, and IL-8 using a commercial cytometric bead array. Significantly higher IFN-γ levels were found in patients with DHF than those with DF. However, significantly higher IL-12p70, TNF-α, and IL-6 levels were associated with DHF only in patients who were infected with DENV2 but not with DENV1. Moreover, patients with DF who were infected with DENV1 showed higher levels of IL-12p70, TNF-α, and IL-6 than patients with DHF early after-fever onset. The IL-8 levels were similar in all cases regardless of the clinical condition or infection serotype. These results suggest that the association between high proinflammatory cytokine levels and dengue disease severity does not always stand, and it once again highlights the complex nature of DHF pathogenesis.

Sequential alcohol oxidation/putative homo Claisen-Tishchenko-type reaction to give esters: a key process in accessing novel biologically active lactone macrocycles

We report an efficient methodology for the direct oxidative esterification of primary alcohols to diether-esters using pyridinium chlorochromate (PCC). Numerous studies were carried out to probe the reaction mechanism and at the same time optimize the reaction conditions. The reaction could be conducted with 1 equivalent of PCC and 1 equivalent of BF3 center dot OEt2. Indications based on literature precedent were that the reaction may proceed via a sequential alcohol oxidation to the aldehyde followed by a putative Cr or boron catalyzed Claisen-Tishchenko-type reaction. Using this efficient methodology, we synthesized a family of novel diether-esters in very good yields; some of these molecules were subsequently tested against both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). In addition, we also disclose a new synthetic strategy for the synthesis of lactam macrocycles with potential biological activity. This methodology included the regioselective borylation of the ester substrate and a subsequent Suzuki-Miyaura coupling to obtain the desired lactam macrocycle.

Primary alkaline battery cathodes a three-scale model

A mathematical model for the galvanostatic discharge and recovery of porous, electrolytic manganese dioxide cathodes, similar to those found within primary alkaline batteries is presented. The phenomena associated with discharge are modeled over three distinct size scales, a cathodic (or macroscopic) scale, a porous manganese oxide particle (or microscopic) scale, and a manganese oxide crystal (or submicroscopic) scale. The physical and chemical coupling between these size scales is included in the model. In addition, the model explicitly accounts for the graphite phase within the cathode. The effects that manganese oxide particle size and proton diffusion have on cathodic discharge and the effects of intraparticle voids and microporous electrode structure are predicted using the model.

Exploring the influence of a science content course incorporating explicit nature of science and argumentation instruction on preservice primary teachers' views of nature of science

There exists a general consensus in the science education literature around the goal of enhancing students. and teachers. views of nature of science (NOS). An emerging area of research in science education explores NOS and argumentation, and the aim of this study was to explore the effectiveness of a science content course incorporating explicit NOS and argumentation instruction on preservice primary teachers. views of NOS. A constructivist perspective guided the study, and the research strategy employed was case study research. Five preservice primary teachers were selected for intensive investigation in the study, which incorporated explicit NOS and argumentation instruction, and utilised scientific and socioscientific contexts for argumentation to provide opportunities for participants to apply their NOS understandings to their arguments. Four primary sources of data were used to provide evidence for the interpretations, recommendations, and implications that emerged from the study. These data sources included questionnaires and surveys, interviews, audio- and video-taped class sessions, and written artefacts. Data analysis involved the formation of various assertions that informed the major findings of the study, and a variety of validity and ethical protocols were considered during the analysis to ensure the findings and interpretations emerging from the data were valid. Results indicated that the science content course was effective in enabling four of the five participants. views of NOS to be changed. All of the participants expressed predominantly limited views of the majority of the examined NOS aspects at the commencement of the study. Many positive changes were evident at the end of the study with four of the five participants expressing partially informed and/or informed views of the majority of the examined NOS aspects. A critical analysis of the effectiveness of the various course components designed to facilitate the development of participants‟ views of NOS in the study, led to the identification of three factors that mediated the development of participants‟ NOS views: (a) contextual factors (including context of argumentation, and mode of argumentation), (b) task-specific factors (including argumentation scaffolds, epistemological probes, and consideration of alternative data and explanations), and (c) personal factors (including perceived previous knowledge about NOS, appreciation of the importance and utility value of NOS, and durability and persistence of pre-existing beliefs). A consideration of the above factors informs recommendations for future studies that seek to incorporate explicit NOS and argumentation instruction as a context for learning about NOS.