A transmission electron microscope study of Néel skyrmion magnetic textures in multilayer thin film systems with large interfacial chiral interaction

Skyrmions in ultrathin ferromagnetic metal (FM)/heavy metal (HM) multilayer systems produced by conventional sputtering methods have recently generated huge interest due to their applications in the field of spintronics. The sandwich structure with two correctly-chosen heavy metal layers provides an additive interfacial exchange interaction which promotes domain wall or skyrmion spin textures that are Néel in character and with a fixed chirality. Lorentz transmission electron microscopy (TEM) is a high resolution method ideally suited to quantitatively image such chiral magnetic configurations. When allied with physical and chemical TEM analysis of both planar and cross-sectional samples, key length scales such as grain size and the chiral variation of the magnetisation variation have been identified and measured. We present data showing the importance of the grain size (mostly < 10 nm) measured from direct imaging and its potential role in describing observed behaviour of isolated skyrmions (diameter < 100 nm). In the latter the region in which the magnetization rotates is measured to be around 30 nm. Such quantitative information on the multiscale magnetisation variations in the system is key to understanding and exploiting the behaviour of skyrmions for future applications in information storage and logic devices.

The Extraction from the Blood of Phosphate Compounds by Canine Bone

Uptake by bone of 99mTc-labeled pyrophosphate (PPj) and ethane-1-hydroxy-1,1-diphosphonate (EHDP) involves passage through capillaries in the Haversian system, extracellular fluid space, and membrane of osteoblasts before adsorption onto available apatite surfaces. Passage through capillaries was studied by the outflow-dilution technique in a canine tibia model in mongrel dogs. slCr-labeled albumin (nondiffusible reference tracer), sucrose (diffusible reference tracer), PPi, and EHDP were injected into the isolated nutrient tibial artery. Blood was collected from the ipsilateral femoral vein every 15 sec for 2 min. Emax, the apparent extraction at the time of the peaks of the dilution curves, is influenced little by back diffusion; for PP, Emax (mean ± SD) = 0.42 ± 0.08 (N = 4); for EHDP, Emax = 0.27 ± 0.05 (N - 10). Net extraction (apparent fractional retention by (pone at 2 min) was 0.36 ± 0.1 for PP. Emax for 8sSr chloride and 18F sodium in our laboratory is 0.69 ± 0.11 (N = 14) and 0.70 ± 0.008 (N = 9), respectively. Permeabilities (P) were calculated by PS = -Fs loge (1-Emax), where Fs = plasma flow and S = capillary surface; the ratio of P for EHDP to P for sucrose was 0.71 which is similar to the ratio of diffusion coefficients, 0.78. The data suggest that EHDP and probably also PPj pass through the capillaries by passive diffusion. As expected, the extraction through capillary walls for EHDP and PPj was lower than that for 8SSr and 18F because of their larger molecular size.

Cefepime plasma concentrations and clinical toxicity: a retrospective cohort study

OBJECTIVES

Cefepime remains an important antibiotic for severe bacterial infections, yet some meta-analyses have shown elevated mortality among patients randomized to it. Therapeutic drug monitoring (TDM) of β-lactam antibiotics is increasing, but optimal plasma concentrations remain unknown. We examined clinical outcomes of patients undergoing cefepime TDM in an initial effort to define the drug's toxicity threshold.

METHODS

In this single-centre retrospective cohort study, we enrolled all adult hospitalized patients receiving cefepime and undergoing TDM from January 2013 through July 2016. The primary outcome was the incidence of clinical toxicity; a secondary outcome was clinical failure. Plasma samples were analysed via high-performance liquid chromatography with ultraviolet detection.

RESULTS

A total of 161 cefepime concentrations were drawn from 93 patients. Roughly half (82/161, 51%) and one-third (49/161, 30%) were trough and steady-state levels from patients receiving intermittent and continuous infusions, respectively; median concentrations were 17.6 mg/L (IQR 9.7-35.2) and 29.2 mg/L (IQR 18.9-45.9). Ten patients (11%) experienced a neurologic event considered at least possibly related to cefepime; neurotoxicity was associated with poorer renal function (median creatinine clearance 54 (IQR 39-97) vs. 75 mL/min/1.73² (IQR 44-104)) and longer cefepime durations (mean 8.3 (SD±6.7) vs. 13.3 days (± 14.2), p = 0.071). Patients with trough levels >20 mg/L had a fivefold higher risk for neurologic events (OR 5.05, 95% CI 1.3-19.8).

CONCLUSIONS

Neurotoxicity potentially related to cefepime occurred at plasma concentrations >35 mg/L. For those receiving intermittent infusions, trough concentrations >20 mg/L should be avoided until further information is available from prospective studies.

RUNX in Invertebrates

Runx genes have been identified in all metazoans and considerable conservation of function observed across a wide range of phyla. Thus, insight gained from studying simple model organisms is invaluable in understanding RUNX biology in higher animals. Consequently, this chapter will focus on the Runx genes in the diploblasts, which includes sea anemones and sponges, as well as the lower triploblasts, including the sea urchin, nematode, planaria and insect. Due to the high degree of functional redundancy amongst vertebrate Runx genes, simpler model organisms with a solo Runx gene, like C. elegans, are invaluable systems in which to probe the molecular basis of RUNX function within a whole organism. Additionally, comparative analyses of Runx sequence and function allows for the development of novel evolutionary insights. Strikingly, recent data has emerged that reveals the presence of a Runx gene in a protist, demonstrating even more widespread occurrence of Runx genes than was previously thought. This review will summarize recent progress in using invertebrate organisms to investigate RUNX function during development and regeneration, highlighting emerging unifying themes.

The Development of an Efficient Test Automation and Sample Tracking System in a High-Throughput Veterinary Laboratory to Improve the Emergency Response to Outbreaks of Highly Infectious Disease in Great Britain

Serological surveillance testing for bovine brucellosis, Enzootic Bovine Leukosis, and Warble fly reaches approximately 1.7 million tests every year in the UK. An automated system was developed to improve the quality of data handling for all three surveys. The objectives were to make improvements in efficiency, sample tracking, and test reporting and to develop an epidemiological database. The developed system of bar-coded samples and test plates processed on automated equipment capable of scanning barcodes and transferring information across a computer network met the data objectives. Consolidating and automating the highly repetitive liquid-handling steps met the cost objectives. To reduce the impact of temporary bottlenecks in the system, a philosophy of ‘islands of automation’ was adopted to maximize the throughput. The creation of this system was driven largely by the need to have in place an effective emergency response capability to handle the serological needs of an outbreak of an acute and highly infectious veterinary disease such as Foot and Mouth Disease (FMD) in the UK.

Integrated palliative care in Europe: a qualitative systematic literature review of empirically-tested models in cancer and chronic disease

BACKGROUND

Integrated Palliative Care (PC) strategies are often implemented following models, namely standardized designs that provide frameworks for the organization of care for people with a progressive life-threatening illness and/or for their (in)formal caregivers. The aim of this qualitative systematic review is to identify empirically-evaluated models of PC in cancer and chronic disease in Europe. Further, develop a generic framework that will consist of the basis for the design of future models for integrated PC in Europe.

METHODS

Cochrane, PubMed, EMBASE, CINAHL, AMED, BNI, Web of Science, NHS Evidence. Five journals and references from included studies were hand-searched. Two reviewers screened the search results. Studies with adult patients with advanced cancer/chronic disease from 1995 to 2013 in Europe, in English, French, German, Dutch, Hungarian or Spanish were included. A narrative synthesis was used.

RESULTS

14 studies were included, 7 models for chronic disease, 4 for integrated care in oncology, 2 for both cancer and chronic disease and 2 for end-of-life pathways. The results show a strong agreement on the benefits of the involvement of a PC multidisciplinary team: better symptom control, less caregiver burden, improvement in continuity and coordination of care, fewer admissions, cost effectiveness and patients dying in their preferred place.

CONCLUSION

Based on our findings, a generic framework for integrated PC in cancer and chronic disease is proposed. This framework fosters integration of PC in the disease trajectory concurrently with treatment and identifies the importance of employing a PC-trained multidisciplinary team with a threefold focus: treatment, consulting and training.

Quasinormal mode theory and design of on-chip single photon emitters in photonic crystal coupled-cavity waveguides

Using a quasinormal mode (QNM) theory for open cavity systems, we present detailed calculations and designs of a photonic crystal nanocavity (PCN) side-coupled to a photonic crystal waveguide (PCW) for on-chip single photon source applications. We investigate various cavity-waveguide geometries using an L3 PCN coupled to a W1 PCW, obtaining the quality factors, effective mode volumes, and single photon Purcell factors of the complete loaded cavity-waveguide system as a function of spatial separation between the two. We also show that the quality factor does not monotonically increase with increasing separation between the PCN and PCW, and we identify a particular hole/defect which acts as the key structural parameter in the cavity-waveguide coupling.