931 research outputs found
The use of electronic voting systems in lectures within business and marketing: a case study of their impact on student learning
This article presents a case study of the impact on student learning of introducing an electronic voting system (EVS) into large‐group lectures for first‐year undergraduate students undertaking degrees in marketing and business systems. We discuss the potential for using EVS‐style interactive lectures in marketing and business programmes. We then describe how we planned the session and selected and implemented the EVS system. We go on to present an evaluative research project, which was undertaken on the innovation using case‐study methodology, and assess its impact on student learning. Data for the evaluation were collected through questionnaire and focus groups with a sample of students. The data were analysed using thematic analysis. The findings show how students perceived the use of EVS in large lectures and how their learning was affected. A ‘three‐fold typology’ emerged that explains how students related to the EVS and how their perceptions of EVS changed over time. The discussion links these findings to the literature on different paradigms of learning and teaching, using Renshaw’s framework, and examines how the EVS‐style lectures promote deep and active learning within the constructivist, social constructivist and metacognitive learning paradigms identified in Renshaw’s model. The conclusions show how the use of a user‐friendly EVS in large lectures motivates students, develops students’ cognitive and social learning skills, and improves learning effectiveness
Iridium(iii) complexes of 1,2,4-triazines as potential bioorthogonal reagents: metal coordination facilitates luminogenic reaction with strained cyclooctynes
In this paper we describe unprecedented Ir(III) complexes of 5-(2-pyridyl)-1,2,4-triazine and their reactivity towards the strained cyclooctyne BCN. The coordination of a 1,2,4-triazine ring to an iridium(III) ion drastically increases the speed of the reaction, showing the second order rate constant of 8 M−1 s−1, the record value to date for a triazine-BCN reaction
A Deep Learning Framework for Predicting Response to Therapy in Cancer
A major challenge in cancer treatment is predicting clinical response to anti-cancer drugs on a personalized basis. Using a pharmacogenomics database of 1,001 cancer cell lines, we trained deep neural networks for prediction of drug response and assessed their performance on multiple clinical cohorts. We demonstrate that deep neural networks outperform the current state in machine learning frameworks. We provide a proof of concept for the use of deep neural network-based frameworks to aid precision oncology strategies
Adatom controlled emergence of high hardness in biocompatible beta-Ti3Au intermetallic thin film surfaces
There is growing international interest in hard biocompatible thin film surface coatings to extend the lifetime of medical implants. Parameters of the physical vapour deposition technique can be utilized to fine tune the microstructure and resulting properties of the growing thin film surface by modifying the adatom mobility of the incoming species. This work investigates the evolution of high hardness and biocompatibility of sputter deposited beta-Ti3Au intermetallic thin film surfaces as a function of growth temperature and pressure. Titanium and gold are sputtered in an optimised 3:1 ratio over glass and Ti6Al4V substrates at varying pressures of 0.3 to 1.2 Pa and temperatures of 25 to 450°C. The microstructure and crystallinity of the deposited films improved with reduction in pressure from 1.2 to 0.3 Pa but development of the β-Ti3Au intermetallic compound occurred at temperatures above 350˚C. The density of the films also increased with reducing pressure, whereas improvement in their columnar structure was observed with increasing substrate temperature. These microstructural changes caused by adatom mobility variation, led to the emergence of superior mechanical surface hardness, reaching a peak value of 12.5 GPa for films grown at 0.3 Pa and 450°C. All thin film surfaces were highly biocompatible with ion leaching levels below 1 ppm, and films deposited at lower pressure exhibited much safer cytotoxic profiles against L929 mouse fibroblasts. This work demonstrates the emergence of high hardness and biocompatibility in Ti3Au thin film surfaces with potential as next generation medical implant coating materials
The PI3-kinase delta inhibitor idelalisib (GS-1101) targets integrin-mediated adhesion of chronic lymphocytic leukemia (CLL) cell to endothelial and marrow stromal cells
CLL cell trafficking between blood and tissue compartments is an integral part of the disease process. Idelalisib, a phosphoinositide 3-kinase delta (PI3K\u3b4) inhibitor causes rapid lymph node shrinkage, along with an increase in lymphocytosis, prior to inducing objective responses in CLL patients. This characteristic activity presumably is due to CLL cell redistribution from tissues into the blood, but the underlying mechanisms are not fully understood. We therefore analyzed idelalisib effects on CLL cell adhesion to endothelial and bone marrow stromal cells (EC, BMSC). We found that idelalisib inhibited CLL cell adhesion to EC and BMSC under static and shear flow conditions. TNF\u3b1-induced VCAM-1 (CD106) expression in supporting layers increased CLL cell adhesion and accentuated the inhibitory effect of idelalisib. Co-culture with EC and BMSC also protected CLL from undergoing apoptosis, and this EC- and BMSC-mediated protection was antagonized by idelalisib. Furthermore, we demonstrate that CLL cell adhesion to EC and VLA-4 (CD49d) resulted in the phosphorylation of Akt, which was sensitive to inhibition by idelalisib. These findings demonstrate that idelalisib interferes with integrin-mediated CLL cell adhesion to EC and BMSC, providing a novel mechanism to explain idelalisib-induced redistribution of CLL cells from tissues into the blood
Novel Docosahexaenoic Acid Ester of Phloridzin Inhibits Proliferation and Triggers Apoptosis in an In Vitro Model of Skin Cancer
Skin cancer is among the most common cancer types accompanied by rapidly increasing incidence rates, thus making the development of more efficient therapeutic approaches a necessity. Recent studies have revealed the potential role of decosahexaenoic acid ester of phloridzin (PZDHA) in suppressing proliferation of liver, breast, and blood cancer cell lines. In the present study, we investigated the cytotoxic potential of PZDHA in an in vitro model of skin cancer consisting of melanoma (A375), epidermoid carcinoma (A431), and non-tumorigenic (HaCaT) cell lines. Decosahexaenoic acid ester of phloridzin led to increased cytotoxicity in all cell lines as revealed by cell viability assays. However, growth inhibition and induction of both apoptosis and necrosis was more evident in melanoma (A375) and epidermoid carcinoma (A431) cells, whereas non-tumorigenic keratinocytes (HaCaT) appeared to be more resistant as detected by flow cytometry. More specifically, PZDHA-induced cell cycle growth arrest at the G2/M phase in A375 and A431 cells in contrast to HaCaT cells, which were growth arrested at the G0/G1 phase. Elevated intracellular generation of reactive oxygen species ROS was detected in all cell lines. Overall, our findings support the potential of PZDHA as a novel therapeutic means against human skin cancer
Naturally Derived Phenethyl Isothiocyanate Modulates Induction of Oxidative Stress via Its \u3ci\u3eN\u3c/i\u3e-Acetylated Cysteine Conjugated form in Malignant Melanoma
Phenethyl isothiocyanate (PEITC) is a secondary metabolic product yielded upon the hydrolysis of gluconasturtiin and it is highly accumulated in the flowers of watercress. The aim of the current study was to assess the role of a naturally derived PEITC-enriched extract in the induction of oxidative stress and to evaluate its anti-melanoma potency through the regulation of its metabolism with the concurrent production of the N-acetyl cysteine conjugated by-product. For this purpose, an in vitro melanoma model was utilized consisting of human primary (A375) cells as well as metastatic (COLO-679) malignant melanoma cells together with non-tumorigenic immortalized keratinocytes (HaCaT). Cytotoxicity was assessed via the Alamar Blue assay whereas the antioxidant/prooxidant activity of PEITC was determined via spectrophotometric assays. Finally, kinetic characterization of the end-product of PEITC metabolism was monitored via UPLC coupled to a tandem mass spectrometry (MS/MS). Our results indicate that although PhEF showed very minor antioxidant activity in a cell-free system, in a cell-based system, it can modulate the activity of key enzyme(s) involved in cellular antioxidant defense mechanism(s). In addition, we have shown that PhEF induces lipid and protein oxidation in a concentration-dependent manner, while its cytotoxicity is not only dependent on PEITC itself but also on its N-acetylated cysteine conjugated form
Metabolic Disorder Dysfunction in Parkinson’s Disease: Bioenergetics, Redox Homeostasis and Central Carbon Metabolism
The loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) and the accumulation of protein inclusions (Lewy bodies) are the pathological hallmarks of Parkinson’s disease (PD). PD is triggered by genetic alterations, environmental/occupational exposures and aging. However, the exact molecular mechanisms linking these PD risk factors to neuronal dysfunction are still unclear. Alterations in redox homeostasis and bioenergetics (energy failure) are thought to be central components of neurodegeneration that contribute to the impairment of important homeostatic processes in dopaminergic cells such as protein quality control mechanisms, neurotransmitter release/metabolism, axonal transport of vesicles and cell survival. Importantly, both bioenergetics and redox homeostasis are coupled to neuro-glial central carbon metabolism. We and others have recently established a link between the alterations in central carbon metabolism induced by PD risk factors, redox homeostasis and bioenergetics and their contribution to the survival/death of dopaminergic cells. In this review, we focus on the link between metabolic dysfunction, energy failure and redox imbalance in PD, making an emphasis in the contribution of central carbon (glucose) metabolism. The evidence summarized here strongly supports the consideration of PD as a disorder of cell metabolism
Chapter 8 The Contribution of Prognostic Factors to the Better Management of Multiple Myeloma Patients
- …
