Solar electric propulsion system tests

Design and performance of solar-powered electric propulsion system for interplanetary space exploratio

Resolving the high redshift Lyman-alpha forest in smoothed particle hydrodynamics simulations

We use a large set of cosmological smoothed particle hydrodynamics (SPH) simulations to examine the effect of mass resolution and box size on synthetic Lya forest spectra at 2 \leq z \leq 5. The mass resolution requirements for the convergence of the mean Lya flux and flux power spectrum at z=5 are significantly stricter than at lower redshift. This is because transmission in the high redshift Lya forest is primarily due to underdense regions in the intergalactic medium (IGM), and these are less well resolved compared to the moderately overdense regions which dominate the Lya forest opacity at z~2-3. We further find that the gas density distribution in our simulations differs significantly from previous results in the literature at large overdensities (\Delta>10). We conclude that studies of the Lya forest at z=5 using SPH simulations require a gas particle mass of M_gas \leq 2x10^5 M_sol/h, which is >8 times the value required at z=2. A box size of at least 40 Mpc/h is preferable at all redshifts.Comment: 5 pages, 5 figures, 2 tables, accepted by MNRA

Deep Submicron III-V on Si-Based Esaki Diode

Esaki tunneling diodes are reemerging as a viable technology option in helping to improve speed and performance of many high speed device applications. The revival of this technology may be linked to the development of new substrates available to research that allows for the fabrication of a device comparable to current silicon technology. Using a 111-V on Silicon Substrate, it was demonstrated that it is possible to create working Esaki Tunneling Diodes

E-Type Delayed Fluorescence of a Phosphine-Supported Cu_2(μ-NAr_2)_2 Diamond Core: Harvesting Singlet and Triplet Excitons in OLEDs

A highly emissive bis(phosphine)diarylamido dinuclear copper(I) complex (quantum yield = 57%) was shown to exhibit E-type delayed fluorescence by variable temperature emission spectroscopy and photoluminescence decay measurement of doped vapor-deposited films. The lowest energy singlet and triplet excited states were assigned as charge transfer states on the basis of theoretical calculations and the small observed S_1−T_1 energy gap. Vapor-deposited OLEDs doped with the complex in the emissive layer gave a maximum external quantum efficiency of 16.1%, demonstrating that triplet excitons can be harvested very efficiently through the delayed fluorescence channel. The function of the emissive dopant in OLEDs was further probed by several physical methods, including electrically detected EPR, cyclic voltammetry, and photoluminescence in the presence of applied current

Training Paradigms in Hepato-Pancreatico-Biliary Surgery: an Overview of the Different Fellowship Pathways

Hepato-pancreatico-biliary (HPB) surgery, and the training of HPB surgeons, has evolved significantly over the last several decades. The current state of training in HPB surgery in North America is defined through three main pathways: the Complex General Surgical Oncology (CGSO) ACGME fellowship, the American Society of Transplant Surgeons (ASTS) fellowship, and the Americas Hepatopancreaticobiliary Association (AHPBA) fellowship. These fellowships offer variable experiences in pancreas, liver, and biliary cases, and each pathway offers a unique perspective on HPB surgery. The CGSO ACGME, ASTS, and AHPBA fellowships represent decades of work by the three major surgical leadership stakeholders to improve and ensure quality training of future HPB surgeons. The best care is provided by the HPB surgeon who has been trained to understand the importance of all available treatment options within the context of a multidisciplinary setting. The three fellowship pathways are outlined in this paper with the nuances and variations characteristic of the different training programs highlighted

The role of the light source in antimicrobial photodynamic therapy

This work was financially supported by the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant (agreement no. 764837) and NCN Opus grant no. 2019/35/B/ST4/03280. We are also grateful to the Engineering and Physical Sciences Research Council of the UK for financial support from grants EP/R511778/1 and EP/L015110/1.Antimicrobial photodynamic therapy (APDT) is a promising approach to fight the growing problem of antimicrobial resistance that threatens health care, food security and agriculture. APDT uses light to excite a light-activated chemical (photosensitiser), leading to the generation of reactive oxygen species (ROS). Many APDT studies confirm its efficacy in vitro and in vivo against bacteria, fungi, viruses and parasites. However, the development of the field is focused on exploring potential targets and developing new photosensitisers. The role of light, a crucial element for ROS production, has been neglected. What are the main parameters essential for effective photosensitiser activation? Does an optimal light radiant exposure exist? And finally, which light source is best? Many reports have described the promising antibacterial effects of APDT in vitro, however, its application in vivo, especially in clinical settings remains very limited. The restricted availability may partially be due to a lack of standard conditions or protocols, arising from the diversity of selected photosensitising agents (PS), variable testing conditions including light sources used for PS activation and methods of measuring anti-bacterial activity and their effectiveness in treating bacterial infections. We thus sought to systematically review and examine the evidence from existing studies on APDT associated with the light source used. We show how the reduction of pathogens depends on the light source applied, radiant exposure and irradiance of light used, and type of pathogen, and so critically appraise the current state of development of APDT and areas to be addressed in future studies. We anticipate that further standardisation of the experimental conditions will help the field advance, and suggest key optical and biological parameters that should be reported in all APDT studies. More in vivo and clinical studies are needed and are expected to be facilitated by advances in light sources, leading to APDT becoming a sustainable, alternative therapeutic option for bacterial and other microbial infections in the future.Publisher PDFPeer reviewe