Effect of Contour Shape of Nervous System Electromagnetic Stimulation Coils on the Induced Electrical Field Distribution

BACKGROUND: Electromagnetic stimulation of the nervous system has the advantage of reduced discomfort in activating nerves. For brain structures stimulation, it has become a clinically accepted modality. Coil designs usually consider factors such as optimization of induced power, focussing, field shape etc. In this study we are attempting to find the effect of the coil contour shape on the electrical field distribution for magnetic stimulation. METHOD AND RESULTS: We use the maximum of the induced electric field stimulation in the region of interest as the optimization criterion. This choice required the application of the calculus of variation, with the contour perimeter taken as a pre-set condition. Four types of coils are studied and compared: circular, square, triangular and an 'optimally' shaped contour. The latter yields higher values of the induced electrical field in depths up to about 30 mm, but for depths around 100 mm, the circular shape has a slight advantage. The validity of the model results was checked by experimental measurements in a tank with saline solution, where differences of about 12% were found. In view the accuracy limitations of the computational and measurement methods used, such differences are considered acceptable. CONCLUSION: We applied an optimization approach, using the calculus of variation, which allows to obtain a coil contour shape corresponding to a selected criterion. In this case, the optimal contour showed higher intensities for a longer line along the depth-axis. The method allows modifying the induced field structure and focussing the field to a selected zone or line

Microscopy in forensic science

This chapter examines the use of electron microscopy, atomic force microscopy and other analytical techniques in forensic investigation and research. These tools can be used to enhance examination of human remains and trace evidence to improve understanding of cause of death, victim identification or post mortem interval.A police-designed scenario is used to highlight trace evidence such as glass, gun shot residue and paint. The validity of forensic techniques is discussed, with reference to international standards, repeatability, and false convictions. Ballistic evidence is used to highlight the complexities in evidence interpretation, including manufacturing variability, environmental effects and likelihood ratios.The use of scanning electron microscopy (SEM), atomic force microscopy (AFM) and other techniques in the development of forensic research is showcased, with particular examples from the field of fingerprints. Examples include improvements in the development of fingermarks from difficult surfaces, interaction of evidence types, and added intelligence from the crime scene, such as forensic timeline or gender of perpetrator

Estimation of current density distribution under electrodes for external defibrillation

BACKGROUND: Transthoracic defibrillation is the most common life-saving technique for the restoration of the heart rhythm of cardiac arrest victims. The procedure requires adequate application of large electrodes on the patient chest, to ensure low-resistance electrical contact. The current density distribution under the electrodes is non-uniform, leading to muscle contraction and pain, or risks of burning. The recent introduction of automatic external defibrillators and even wearable defibrillators, presents new demanding requirements for the structure of electrodes. METHOD AND RESULTS: Using the pseudo-elliptic differential equation of Laplace type with appropriate boundary conditions and applying finite element method modeling, electrodes of various shapes and structure were studied. The non-uniformity of the current density distribution was shown to be moderately improved by adding a low resistivity layer between the metal and tissue and by a ring around the electrode perimeter. The inclusion of openings in long-term wearable electrodes additionally disturbs the current density profile. However, a number of small-size perforations may result in acceptable current density distribution. CONCLUSION: The current density distribution non-uniformity of circular electrodes is about 30% less than that of square-shaped electrodes. The use of an interface layer of intermediate resistivity, comparable to that of the underlying tissues, and a high-resistivity perimeter ring, can further improve the distribution. The inclusion of skin aeration openings disturbs the current paths, but an appropriate selection of number and size provides a reasonable compromise

Perspectives for next generation lithium-ion battery cathode materials

Transitioning to electrified transport requires improvements in sustainability, energy density, power density, lifetime, and approved the cost of lithium-ion batteries, with significant opportunities remaining in the development of next-generation cathodes. This presents a highly complex, multiparameter optimization challenge, where developments in cathode chemical design and discovery, theoretical and experimental understanding, structural and morphological control, synthetic approaches, and cost reduction strategies can deliver performance enhancements required in the near- and longer-term. This multifaceted challenge requires an interdisciplinary approach to solve, which has seen the establishment of numerous academic and industrial consortia around the world to focus on cathode development. One such example is the Next Generation Lithium-ion Cathode Materials project, FutureCat, established by the UK’s Faraday Institution for electrochemical energy storage research in 2019, aimed at developing our understanding of existing and newly discovered cathode chemistries. Here, we present our perspective on persistent fundamental challenges, including protective coatings and additives to extend lifetime and improve interfacial ion transport, the design of existing and the discovery of new cathode materials where cation and cation-plus-anion redox-activity can be exploited to increase energy density, the application of earth-abundant elements that could ultimately reduce costs, and the delivery of new electrode topologies resistant to fracture which can extend battery lifetime

Perspectives for next generation lithium-ion battery cathode materials

Transitioning to electrified transport requires improvements in sustainability, energy density, power density, lifetime, and approved the cost of lithium-ion batteries, with significant opportunities remaining in the development of next-generation cathodes. This presents a highly complex, multiparameter optimization challenge, where developments in cathode chemical design and discovery, theoretical and experimental understanding, structural and morphological control, synthetic approaches, and cost reduction strategies can deliver performance enhancements required in the near- and longer-term. This multifaceted challenge requires an interdisciplinary approach to solve, which has seen the establishment of numerous academic and industrial consortia around the world to focus on cathode development. One such example is the Next Generation Lithium-ion Cathode Materials project, FutureCat, established by the UK’s Faraday Institution for electrochemical energy storage research in 2019, aimed at developing our understanding of existing and newly discovered cathode chemistries. Here, we present our perspective on persistent fundamental challenges, including protective coatings and additives to extend lifetime and improve interfacial ion transport, the design of existing and the discovery of new cathode materials where cation and cation-plus-anion redox-activity can be exploited to increase energy density, the application of earth-abundant elements that could ultimately reduce costs, and the delivery of new electrode topologies resistant to fracture which can extend battery lifetime.</jats:p

The effect of antecedent hypoglycaemia on β2-adrenergic sensitivity in healthy participants with the Arg16Gly polymorphism of the β2-adrenergic receptor

Contains fulltext : 96423.pdf (publisher's version ) (Closed access)AIMS/HYPOTHESIS: Homozygosity for glycine at codon 16 (GlyGly) of the beta(2)-adrenergic receptor may alter receptor sensitivity upon chronic stimulation and has been implicated in the pathogenesis of hypoglycaemia unawareness. We compared the effect of antecedent hypoglycaemia on beta(2)-adrenergic receptor sensitivity between GlyGly participants and those with arginine 16 homozygosity (ArgArg) for the beta(2)-adrenergic receptor. METHODS: We enrolled 16 healthy participants, who were either GlyGly (n = 8) or ArgArg (n = 8). They participated randomly in two 2 day experiments. Day 1 consisted of two 2-h hyperinsulinaemic hypoglycaemic (2.8 mmol/l) or euglycaemic (4.8 mmol/l) glucose clamps. On day 2, we measured the forearm vasodilator response to the beta(2)-adrenergic receptor agonist salbutamol and the dose of isoprenaline required to increase the heart rate by 25 bpm (IC(25)). RESULTS: The vasodilator response to salbutamol tended to be greater after antecedent hypoglycaemia than after euglycaemia (p = 0.078), consistent with increased beta(2)-adrenergic receptor sensitivity. This effect was driven by a significant increase in beta(2)-adrenergic receptor sensitivity following hypoglycaemia compared with euglycaemia in ArgArg participants (p = 0.019), whereas no such effect was observed in the GlyGly participants. Antecedent hypoglycaemia tended to decrease the IC(25) in ArgArg participants, whereas the reverse occurred in the GlyGly participants (GlyGly vs ArgArg group p = 0.047). CONCLUSION/INTERPRETATION: Antecedent hypoglycaemia did not affect beta(2)-adrenergic receptor sensitivity in healthy GlyGly participants, but increased it in ArgArg participants. If these results also hold for participants with type 1 diabetes, such an increase in beta(2)-adrenergic receptor sensitivity may potentially reduce the risk of repeated hypoglycaemia and the subsequent development of hypoglycaemia unawareness in ArgArg diabetic participants. TRIAL REGISTRATION: ClinicalTrials.gov NCT00160056

Evidence-based guidelines for treating bipolar disorder: revised third edition recommendations from the British Association for Psychopharmacology

The British Association for Psychopharmacology guidelines specify the scope and targets of treatment for bipolar disorder. The third version is based explicitly on the available evidence and presented, like previous Clinical Practice Guidelines, as recommendations to aid clinical decision making for practitioners: it may also serve as a source of information for patients and carers, and assist audit. The recommendations are presented together with a more detailed review of the corresponding evidence. A consensus meeting, involving experts in bipolar disorder and its treatment, reviewed key areas and considered the strength of evidence and clinical implications. The guidelines were drawn up after extensive feedback from these participants. The best evidence from randomized controlled trials and, where available, observational studies employing quasi-experimental designs was used to evaluate treatment options. The strength of recommendations has been described using the GRADE approach. The guidelines cover the diagnosis of bipolar disorder, clinical management, and strategies for the use of medicines in short-term treatment of episodes, relapse prevention and stopping treatment.The use of medication is integrated with a coherent approach to psychoeducation and behaviour change

Cohesion, consensus, and conflict:Technocratic elites and financial crisis in Mexico and Argentina

Observers of economic policy-making in developing countries often suggest that consensus and cohesion within technocratic policy elites facilitate the implementation and consolidation of reforms, but have not clearly defined these terms or the relationship between them. Likewise, political sociologists argue that social networks account for elite cohesion, but have not adequately specified the relevant structural properties of these networks. This article argues that structural network cohesion facilitates elite consensus formation by enabling cooperation, while fragmented networks promote competition between factions and hence conflict. I support this hypothesis empirically by examining two cases in which elite consensus was severely challenged by financial crises: Mexico and Argentina. Mexican policy elites sustained consensus throughout the crisis, whereas conflict plagued the Argentine elite. Likewise, while the Mexican technocratic elite is highly cohesive, the Argentine elite is fragmented and factionalized. I document this hypothesis using a mixed-methods approach that embeds an analysis of elite networks within a comparative analysis of policy-making patterns drawing on extensive fieldwork in both countries

Aspergillus fumigatus Stimulates the NLRP3 Inflammasome through a Pathway Requiring ROS Production and the Syk Tyrosine Kinase

Invasive aspergillosis (IA) is a life-threatening disease that occurs in immunodepressed patients when infected with Aspergillus fumigatus. This fungus is the second most-common causative agent of fungal disease after Candida albicans. Nevertheless, much remains to be learned about the mechanisms by which A. fulmigatus activates the innate immune system. We investigated the inflammatory response to conidia and hyphae of A. fumigatus and specifically, their capacity to trigger activation of an inflammasome. Our results show that in contrast to conidia, hyphal fragments induce NLRP3 inflammasome assembly, caspase-1 activation and IL-1β release from a human monocyte cell line. The ability of Aspergillus hyphae to activate the NLRP3 inflammasome in the monocytes requires K+ efflux and ROS production. In addition, our data show that NLRP3 inflammasome activation as well as pro-IL-1β expression relies on the Syk tyrosine kinase, which is downstream from the pathogen recognition receptor Dectin-1, reinforcing the importance of Dectin-1 in the innate immune response against fungal infection. Furthermore, we show that treatment of monocytes with corticosteroids inhibits transcription of the gene encoding IL-1β. Thus, our data demonstrate that the innate immune response against A. fumigatus infection involves a two step activation process, with a first signal promoting expression and synthesis of pro-IL-1β; and a second signal, involving Syk-induced activation of the NLRP3 inflammasome and caspase-1, allowing processing and secretion of the mature cytokine