Patterning of metal oxide thin films using a H₂/He atmospheric pressure plasma jet

A hydrogen-doped helium atmospheric pressure plasma jet (APPJ) is shown to be effective for the chemical reduction of metal oxides. Copper and tin oxide films (CuO and SnO2) show rapid (<2 seconds) and complete reduction to zero valence metal after exposure to the plasma jet, as revealed by X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy, and Raman spectroscopy. After a total residence time of the plasma jet of 100 seconds, titanium oxide (TiO2) produced a surface decorated with Ti2+, Ti3+ and Ti4+ with proportions of 16, 38 and 46 atom%, respectively, as determined by XPS peak integration. Similarly, with tungsten oxide (WO3), after exposure for a few seconds, W5+ was produced, yielding a deep blue electrically conductive coating. The treatment of these oxide films by this dielectric radio frequency (RF) barrier discharge plasma jet provides a level of redox conversion not seen in any other technique, particularly for TiO2, especially with a comparable power input. The precise nature of the reduction is unclear; however, the involvement of free electrons may have an important role in the reduction process

Strong oviposition preference for Bt over non-Bt maize in Spodoptera frugiperda and its implications for the evolution of resistance

BACKGROUND: Transgenic crops expressing Bt toxins have substantial benefits for growers in terms of reduced synthetic insecticide inputs, area-wide pest management and yield. This valuable technology depends upon delaying the evolution of resistance. The ‘high dose/refuge strategy’, in which a refuge of non-Bt plants is planted in close proximity to the Bt crop, is the foundation of most existing resistance management. Most theoretical analyses of the high dose/refuge strategy assume random oviposition across refugia and Bt crops. RESULTS: In this study we examined oviposition and survival of Spodoptera frugiperda across conventional and Bt maize and explored the impact of oviposition behavior on the evolution of resistance in simulation models. Over six growing seasons oviposition rates per plant were higher in Bt crops than in refugia. The Cry1F Bt maize variety retained largely undamaged leaves, and oviposition preference was correlated with the level of feeding damage in the refuge. In simulation models, damage-avoiding oviposition accelerated the evolution of resistance and either led to requirements for larger refugia or undermined resistance management altogether. Since larval densities affected oviposition preferences, pest population dynamics affected resistance evolution: larger refugia were weakly beneficial for resistance management if they increased pest population sizes and the concomitant degree of leaf damage. CONCLUSIONS: Damaged host plants have reduced attractiveness to many insect pests, and crops expressing Bt toxins are generally less damaged than conventional counterparts. Resistance management strategies should take account of this behavior, as it has the potential to undermine the effectiveness of existing practice, especially in the tropics where many pests are polyvoltinous. Efforts to bring down total pest population sizes and/or increase the attractiveness of damaged conventional plants will have substantial benefits for slowing the evolution of resistance

Inflammation following acute myocardial infarction: Multiple players, dynamic roles, and novel therapeutic opportunities

Acute myocardial infarction (AMI) and the heart failure that often follows, are major causes of death and disability worldwide. As such, new therapies are required to limit myocardial infarct (MI) size, prevent adverse left ventricular (LV) remodeling, and reduce the onset of heart failure following AMI. The inflammatory response to AMI, plays a critical role in determining MI size, and a persistent pro-inflammatory reaction can contribute to adverse post-MI LV remodeling, making inflammation an important therapeutic target for improving outcomes following AMI. In this article, we provide an overview of the multiple players (and their dynamic roles) involved in the complex inflammatory response to AMI and subsequent LV remodeling, and highlight future opportunities for targeting inflammation as a therapeutic strategy for limiting MI size, preventing adverse LV remodeling, and reducing heart failure in AMI patients

Unique morphological characteristics of mitochondrial subtypes in the heart: the effect of ischemia and ischemic preconditioning.

RATIONALE: Three subsets of mitochondria have been described in adult cardiomyocytes - intermyofibrillar (IMF), subsarcolemmal (SSM), and perinuclear (PN). They have been shown to differ in physiology, but whether they also vary in morphological characteristics is unknown. Ischemic preconditioning (IPC) is known to prevent mitochondrial dysfunction induced by acute myocardial ischemia/reperfusion injury (IRI), but whether IPC can also modulate mitochondrial morphology is not known. AIMS: Morphological characteristics of three different subsets of adult cardiac mitochondria along with the effect of ischemia and IPC on mitochondrial morphology will be investigated. METHODS: Mouse hearts were subjected to the following treatments (N=6 for each group): stabilization only, IPC (3x5 min cycles of global ischemia and reperfusion), ischemia only (20 min global ischemia); and IPC and ischemia. Hearts were then processed for electron microscopy and mitochondrial morphology was assessed subsequently. RESULTS: In adult cardiomyocytes, IMF mitochondria were found to be more elongated and less spherical than PN and SSM mitochondria. PN mitochondria were smaller in size when compared to the other two subsets. SSM mitochondria had similar area to IMF mitochondria but their sphericity measures were similar to PN mitochondria. Ischemia was shown to increase the sphericity parameters of all 3 subsets of mitochondria; reduce the length of IMF mitochondria, and increase the size of PN mitochondria. IPC had no effect on mitochondrial morphology either at baseline or after ischemia. CONCLUSION: The three subsets of mitochondria in the adult heart are morphologically different. IPC does not appear to modulate mitochondrial morphology in adult cardiomyocytes

Role of Macrophages in Cardioprotection

Cardiovascular diseases are the leading cause of mortality worldwide. It is widely known that non-resolving inflammation results in atherosclerotic conditions, which are responsible for a host of downstream pathologies including thrombosis, myocardial infarction (MI), and neurovascular events. Macrophages, as part of the innate immune response, are among the most important cell types in every stage of atherosclerosis. In this review we discuss the principles governing macrophage function in the healthy and infarcted heart. More specifically, how cardiac macrophages participate in myocardial infarction as well as cardiac repair and remodeling. The intricate balance between phenotypically heterogeneous populations of macrophages in the heart have profound and highly orchestrated effects during different phases of myocardial infarction. In the early "inflammatory" stage of MI, resident cardiac macrophages are replaced by classically activated macrophages derived from the bone marrow and spleen. And while the macrophage population shifts towards an alternatively activated phenotype, the inflammatory response subsides giving way to the "reparative/proliferative" phase. Lastly, we describe the therapeutic potential of cardiac macrophages in the context of cell-mediated cardio-protection. Promising results demonstrate innovative concepts; one employing a subset of yolk sac-derived, cardiac macrophages that have complete restorative capacity in the injured myocardium of neonatal mice, and in another example, post-conditioning of cardiac macrophages with cardiosphere-derived cells significantly improved patient's post-MI diagnoses

Full left ventricular coverage is essential for the accurate quantification of the area- at- risk by T1 and T2 mapping

T2-weighted cardiovascular magnetic resonance (CMR) using a 3-slice approach has been shown to accurately quantify the edema-based area-at-risk (AAR) in ST-segment elevation myocardial infarction (STEMI). We aimed to compare the performance of a 3-slice approach to full left ventricular (LV) coverage for the AAR by T1 and T2 mapping and MI size. Forty-eight STEMI patients were prospectively recruited and underwent a CMR at 4 ± 2 days. There was no difference between the AARfull LV and AAR3-slices by T1 (P = 0.054) and T2-mapping (P = 0.092), with good correlations but small biases and wide limits of agreements (T1-mapping: N = 30, R2 = 0.85, bias = 1.7 ± 9.4% LV; T2-mapping: N = 48, R2 = 0.75, bias = 1.7 ± 12.9% LV). There was also no significant difference between MI size3-slices and MI sizefull LV (P = 0.93) with an excellent correlation between the two (R2 0.92) but a small bias of 0.5% and a wide limit of agreement of ±7.7%. Although MSI was similar between the 2 approaches, MSI3-slices performed poorly when MSI was <0.50. Furthermore, using AAR3-slices and MI sizefull LV resulted in ‘negative’ MSI in 7/48 patients. Full LV coverage T1 and T2 mapping are more accurate than a 3-slice approach for delineating the AAR, especially in those with MSI < 0.50 and we would advocate full LV coverage in future studies

A Dynamic Knowledge Management Framework for the High Value Manufacturing Industry

Dynamic Knowledge Management (KM) is a combination of cultural and technological factors, including the cultural factors of people and their motivations, technological factors of content and infrastructure and, where these both come together, interface factors. In this paper a Dynamic KM framework is described in the context of employees being motivated to create profit for their company through product development in high value manufacturing. It is reported how the framework was discussed during a meeting of the collaborating company’s (BAE Systems) project stakeholders. Participants agreed the framework would have most benefit at the start of the product lifecycle before key decisions were made. The framework has been designed to support organisational learning and to reward employees that improve the position of the company in the market place

The Role of Redox Dysregulation in the Inflammatory Response to Acute Myocardial Ischaemia-reperfusion Injury - Adding Fuel to the Fire

Background: The inflammatory response to acute myocardial ischaemia/ reperfusion injury (IRI) plays a critical role in determining myocardial infarct (MI) size, and subsequent post-MI left ventricular (LV) remodelling, making it a potential therapeutic target for improving clinical outcomes in patients presenting with an acute myocardial infarction (AMI). Recent experimental studies using advanced imaging and molecular techniques, have yielded new insights into the mechanisms through which reactive oxygen species (ROS) contribute to the inflammatory response induced by acute myocardial IRI - “adding fuel to the fire”. The infiltration of inflammatory cells into the MI zone, leads to elevated myocardial concentrations of ROS, cytokine release, and activation of apoptotic and necrotic death pathways. Anti-oxidant and anti-inflammatory therapies have failed to protect the heart against acute myocardial IRI. This may be, in part, due to a lack of understanding of the time course, nature and mechanisms of the inflammation and redox dysregulation, which occur in the setting of acute myocardial IRI. Conclusion: In this article, we examine the inflammatory response and redox dysregulation induced by acute myocardial IRI, and highlight potential therapeutic options for targeting redox dysregulation, in order to attenuate the detrimental effects of the inflammatory response following an AMI, so as to reduce MI size and prevent heart failure

The 10th Biennial Hatter Cardiovascular Institute workshop: cellular protection—evaluating new directions in the setting of myocardial infarction, ischaemic stroke, and cardio-oncology

Due to its poor capacity for regeneration, the heart is particularly sensitive to the loss of contractile cardiomyocytes. The onslaught of damage caused by ischaemia and reperfusion, occurring during an acute myocardial infarction and the subsequent reperfusion therapy, can wipe out upwards of a billion cardiomyocytes. A similar program of cell death can cause the irreversible loss of neurons in ischaemic stroke. Similar pathways of lethal cell injury can contribute to other pathologies such as left ventricular dysfunction and heart failure caused by cancer therapy. Consequently, strategies designed to protect the heart from lethal cell injury have the potential to be applicable across all three pathologies. The investigators meeting at the 10th Hatter Cardiovascular Institute workshop examined the parallels between ST-segment elevation myocardial infarction (STEMI), ischaemic stroke, and other pathologies that cause the loss of cardiomyocytes including cancer therapeutic cardiotoxicity. They examined the prospects for protection by remote ischaemic conditioning (RIC) in each scenario, and evaluated impasses and novel opportunities for cellular protection, with the future landscape for RIC in the clinical setting to be determined by the outcome of the large ERIC-PPCI/CONDI2 study. It was agreed that the way forward must include measures to improve experimental methodologies, such that they better reflect the clinical scenario and to judiciously select combinations of therapies targeting specific pathways of cellular death and injury