Rapid polarization mapping in ferroelectrics using Fourier masking

Ferroelectric materials, and more specifically ferroelectric domain walls (DWs) have become an area of intense research in recent years. Novel physical phenomena have been discovered at these nanoscale topological polarization discontinuities by mapping out the polarization in each atomic unit cell around the DW in a scanning transmission electron microscope (STEM). However, identifying these features requires an understanding of the polarization in the overall domain structure of the TEM sample, which is often a time-consuming process. Here, a fast method of polarization mapping in the TEM is presented, which can be applied to a range of ferroelectric materials. Due to the coupling of polarization to spontaneous strain, we can isolate different strain states and demonstrate the fast mapping of the domain structure in ferroelectric lead titanate (PTO). The method only requires a high-resolution TEM or STEM image and is less sensitive to zone axis or local strain effects, which may affect other techniques. Thus, it is easily applicable to in-situ experiments. The complimentary benefits of Fourier masking with more advanced mapping strategies and its application to other materials are discussed. These results imply that Fourier masked polarization mapping will be a useful tool for electron microscopists in streamlining their analysis of ferroelectric TEM samples. LAY DESCRIPTION: This paper addresses a problem that often occurs when looking at a ferroelectric material in the Transmission Electron Microscope (TEM). Ferroelectric samples are interesting because they form tiny areas inside themselves with arrow of charge in each one. The thinner the sample, the smaller these regions, called "domains" become. These arrows of charge point in different directions in each domain of the sample. The boundary where these domains meet have interesting properties to study in a TEM but it's important to figure out which way the arrows point in the domains around the boundary. What causes the arrows in the different domains is tiny shifts of different atoms in unit cell away from their neutral position, usually because they're being squeezed by pressure from the domains nearby. The problem is that these tiny atoms moving are difficult to measure and see where the charged arrow is pointing, often it's hard to know how many different domains are even in the sample and where they begin. This paper discusses a method called "Fourier masking" to quickly see what's going on in the overall TEM sample, where the domains are and roughly where the arrows point. It does this by looking at the spacings of the atoms from a magnification where you can just about see the lines of atoms. In lead titanate the unit cell is a rectangle and the arrow always points in line with the long side of the rectangle. The Fourier masking lets you see which direction the long side of the rectangular unit cell is pointing in different parts of your TEM image. The big advantage is that it takes about two minutes to do and uses software that almost every TEM already has. That lets the TEM user quickly know where the domains are in their TEM samples and roughly which way the arrows of charge are pointing. Then they can choose the most interesting features focus on for higher resolution analysis.

The advantages of UK Biobank's open-access strategy for health research

Ready access to health research studies is becoming more important as researchers, and their funders, seek to maximize the opportunities for scientific innovation and health improvements. Large-scale population-based prospective studies are particularly useful for multidisciplinary research into the causes, treatment and prevention of many different diseases. UK Biobank has been established as an open-access resource for public health research, with the intention of making the data as widely available as possible in an equitable and transparent manner. Access to UK Biobank's unique breadth of phenotypic and genetic data has attracted researchers worldwide from across academia and industry. As a consequence, it has enabled scientists to perform world-leading collaborative research. Moreover, open access to an already deeply characterized cohort has encouraged both public and private sector investment in further enhancements to make UK Biobank an unparalleled resource for public health research and an exemplar for the development of open-access approaches for other studies.

Perioperative Complications in Patients with Drug-Eluting Stents: A Three-Year Audit at Geelong Hospital

Drug-eluting stents are a recommended treatment for lesions in the coronary arteries. Stent insertion requires the patient remain on antiplatelet medication for a minimum of six months after insertion. A serious consequence of ceasing antiplatelet medication is late stent thrombosis leading to myocardial infarction in the territory of the drug-eluting stent. Continuing antiplatelet medication can lead to excessive bleeding at the time of surgery. Understanding the risk of complications attributable to bleeding or myocardial ischaemia will help in defining the optimal management of these patients at the time of noncardiac surgery.

This study is a retrospective database analysis and case note review of all patients with drug-eluting stents presenting for noncardiac surgical procedures over a three-year period in one centre.

Twenty-four patients with drug-eluting stents inserted presented for 43 noncardiac surgical procedures. Severe bleeding problems were encountered in one case. Three of 15 patients (20%) who ceased clopidogrel prior to surgery without alternative anti-thrombotic prophylaxis suffered myocardial infarction due to stent thrombosis. Four patients who received alternative anti-thrombotic prophylaxis did not suffer complications. All 19 patients who ceased clopidogrel remained on aspirin prior to surgery.

Patients treated with drug-eluting stents for coronary artery stenosis represent a challenging group of patients for subsequent perioperative management. The risk of myocardial infarction when clopidogrel is stopped prior to surgery is 20%, if alternative anti-thrombotic prophylaxis is not used. This risk persists beyond one year after insertion of drug-eluting stents. Some treatments appear to be effective in reducing the risk of myocardial infarction.

Epidemiology of road traffic accidents in cats attending emergency-care practices in the UK

OBJECTIVES

To estimate the incidence proportion of road traffic accidents in cats attending emergency out-of-hours clinics in the UK, identify major risk factors for road traffic accident occurrence and for survival to discharge.

MATERIALS AND METHODS

A retrospective study of a cohort of 33,053 cats in the VetCompass database attending emergency-care practice between January 1, 2012 and February 15, 2014. Incidence proportion was calculated and logistic regression was used to identify risk factors for road traffic accident and survival to discharge following road traffic accident.

RESULTS

Incidence proportion was estimated at 4∙2% (95% confidence interval: 4∙0 to 4∙4%). Cats aged 6 months to 2 years were at increased odds of road traffic accident, as were male cats and crossbred cats. Odds of road traffic accident were highest in the autumn. Spinal injury, abdominal injury and increasing count of injuries were associated with increased odds of death.

CLINICAL SIGNIFICANCE

Road traffic accident is a frequent presentation in emergency-care practice. Identification of risk factors for death within the first 24 hours following a road traffic accident can aid veterinarian and owner decision-making for treatment of cats involved in a road traffic accident.

Sarcomatoid Carcinoma of the Prostate Presenting in a 44 Year Old

We present the case of a 44-year-old man diagnosed with metastatic sarcomatoid carcinoma of the prostate. The pathogenesis and optimal treatment of this rare and aggressive subtype of prostate cancer are not fully clear. The patient was managed using a multimodality approach of chemotherapy, hormonal blockade and radiation therapy, with palliative intent.

Mortality and long-term dialysis requirement among elderly continuous renal replacement therapy patients in a tertiary referral intensive care unit

Background

Elderly patients are frequently considered poor candidates for continuous renal replacement therapy in intensive care units, but with little evidence base.

Methods

We gathered data regarding patients requiring continuous renal replacement therapy at our institution's intensive care unit during 2012-2014, and compared outcomes between patients of 75 years or older, and younger patients.

Results

Older patients had similar intensive care unit mortality to younger patients (41.5% vs. 36.1%, p = 0.21), but higher hospital mortality (54.2% vs. 44.0%, p = 0.02), and one-year mortality (63.6% vs. 50.6%, p = 0.005). There were no significant differences in dialysis-dependence rates between older and younger patients at intensive care unit discharge (31.9% vs. 35.8%, p = 0.50), and hospital discharge (18.5% vs. 24.2%, 0.32). Rates of new dialysis-dependence between older and younger patients at time of hospital discharge were similar (10.2% vs. 6.0%, p = 0.20).

Conclusions

Intensivists should not withhold continuous renal replacement therapy based on age alone. Other factors should be considered in triage of patients for intensive care unit and continuous renal replacement therapy.

Hypoxia-Activated Alkylating Agents in BRCA1-Mutant Ovarian Serous Carcinoma

Breast cancer 1 antigen (BRCA 1) and breast cancer 2 antigen (BRCA2) genes play a significant role in deoxyribonucleic acid (DNA) repair by means of interstrand crosslink repair, and deleterious germline mutations of these are responsible for most hereditary breast and ovarian cancers. Therapeutic strategies which specifically target interstrand crosslink repair can therefore be helpful in patients with harmful mutations. We describe two patients with advanced ovarian cancer and deleterious BRCA1 mutations who were treated with TH-302, a hypoxia-activated alkylating agent.

Prevalence of BRCA1/2 mutations among an Irish cohort unrestricted by testing eligibility thresholds

e13013

Background: Diagnostic criteria for BRCA1/2 genetic testing vary worldwide. Different eligibility thresholds for testing are used in different healthcare systems. In the public system in Ireland, this threshold is based on the Manchester Score (MS), with a score of ≥16 (approximately 10% likelihood of BRCA1/2 mutation) required for testing. Individuals unaffected by cancer are not eligible for diagnostic testing. Testing is also available privately by self-paying. We reviewed all self-pay patients in Ireland who were unrestricted by national guidelines. Methods: We performed a retrospective chart review of results from BRCA1/2 genetic testing in the Mater Private Hospital genetics clinic. Outcomes were recorded as ‘positive’, ‘wild type’ or ‘variant of uncertain significance’ (VUS). Results: 276 patients underwent testing between 2011 and 2016. 203 were affected with a median age of diagnosis of 48 (range 14-76), and 73 were unaffected individuals with a median age of 45 (range 30-74) at testing. 103 affected patients had a MS of ≥ 16: 7(6.8%) tested positive for BRCA1 mutation and 11(10.7%) tested positive for a BRCA2 mutation. Seven (6.8%) had a VUS characterised. 100 affected patients had an MS of <16: 3(3%) tested positive for a BRCA1 mutation and 5(5%)tested positive for a BRCA2 mutation. Eight (8%) had a VUS identified. 39 unaffected individuals had a MS ≥ 16: 6(15.4%) tested positive for a BRCA1 mutation, and 1(2.6%) for a BRCA2 mutation. 5(12.8%) had a VUS. 34 unaffected patients had an MS of <16: 2 (5.8%) tested positive for a BRCA2 mutation and 1 (2.9%) had a VUS. A total of 134 patients had a MS<16, and the prevalence of BRCA1/2 mutation in this group was 7% (n=10). Conclusions: The mutation detection rate was higher than expected in unaffected individuals and individuals belonging to families with MS < 16. Scoring systems such as the MS help to prioritise resources but miss many BRCA1/2 mutation carriers. [Table: see text]

The development of an abbreviated version of the Cornell scale for depression in dementia (CSDD) for the assessment of depression in palliative care inpatients

Introduction

In the palliative care setting, accurate identification of depression is important to allow delivery of appropriate treatments.

Aims:

– 1. To assess rates of depression in palliative care inpatients using the CSDD, comparing with formal clinical diagnosis based on diagnostic and statistical manual of mental disorders (DSM-IV) criteria;

– 2. To identify items of the CSDD that most distinguish depressive illness in a palliative care setting.

Methods

We measured rates of depression in patients admitted into a palliative care inpatient unit with the CSDD. DSM-IV clinical diagnosis of major depressive disorder (MDD) was achieved using all available clinical information by an experienced independent rater. We calculated Cohen's Kappa to measure concordance between the CSDD and DSM-IV diagnosis.

Results

We assessed 142 patients (56.3% male; mean age: 69.6 years), the majority of which had a cancer diagnosis (93.7%). 18.3% (n = 26) met DSM-IV criteria for MDD, while 12% scored ≥6 on the CSDD with 15 cases of depression common to these two methods (K = 0.65). Discriminant analysis identified five CSDD items that were especially distinguishing of MDD; sadness, loss of interest, pessimism, lack of reactivity to pleasant events and appetite loss. An abbreviated version of the CSDD, based on these 5 items, proved highly accurate in identifying DSM-IV MDD (AUC = 0.94), with sensitivity of 89% and specificity of 84% at a cut-off score ≥2.

Conclusions

There was good level of concordance between the CSDD and DSM-IV diagnosis of MDD. We identified five depressive symptoms that are especially discriminating for depression in palliative care patients.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Correction: Site controlled red-yellow-green light emitting InGaN quantum discs on nano-tipped GaN rods

Correction for 'Site controlled red-yellow-green light emitting InGaN quantum discs on nano-tipped GaN rods' by M. Conroy et al., Nanoscale, 2016, 8, 11019-11026.

Site controlled red-yellow-green light emitting InGaN quantum discs on nano-tipped GaN rods

We report a method of growing site controlled InGaN multiple quantum discs (QDs) at uniform wafer scale on coalescence free ultra-high density (>80%) nanorod templates by metal organic chemical vapour deposition (MOCVD). The dislocation and coalescence free nature of the GaN space filling nanorod arrays eliminates the well-known emission problems seen in InGaN based visible light sources that these types of crystallographic defects cause. Correlative scanning transmission electron microscopy (STEM), energy-dispersive X-ray (EDX) mapping and cathodoluminescence (CL) hyperspectral imaging illustrates the controlled site selection of the red, yellow and green (RYG) emission at these nano tips. This article reveals that the nanorod tips' broad emission in the RYG visible range is in fact achieved by manipulating the InGaN QD's confinement dimensions, rather than significantly increasing the In%. This article details the easily controlled method of manipulating the QDs dimensions producing high crystal quality InGaN without complicated growth conditions needed for strain relaxation and alloy compositional changes seen for bulk planar GaN templates.

Characterization of Carbon Nanotube Growth via CVD Synthesis from a Liquid Precursor

As novel theories and uses of carbon nanotubes (CNT) advance, it becomes increasingly important to characterize the methods of production. One such method of CNT production uses a liquid phase precursor (hydrocarbon with nanoparticle catalyst mix) that is injected into a tube furnace with a flowing carrier gas. The CNTs are grown in high purity and are collected on the surface of the quartz tube. The system allows for a number of variables to be tested such as growth temperatures, flow rate of the carrier gas, precursor injection rates and variations of precursor mix however, here only thermal effects are considered. Under thermal conditions ranging from 500 to 850°C, multi-walled carbon nanotubes (MWCNTs) are synthesized and characterized to determine inner and outer diameter as well as tube thickness.

Pemphigoid gestationis: a case report and review of the literature

Pemphigoid gestationis (PG) is an uncommon autoimmune bullous disease that almost exclusively presents during pregnancy. Patients typically present with a diffuse blistering and intensely pruritic eruption that begins periumbilically and spreads to involve the rest of the body. Direct immunofluorescence demonstrating C3 in a linear pattern along the dermoepidermal junction confirms the diagnosis of PG. Corticosteroids remain the choice of therapy and early intervention is essential because of possible adverse effects of PG on the fetus. We report a case of PG and review the literature.

Validation of the confusion assessment method in the palliative care setting

The Confusion Assessment Method (CAM) is widely used in the palliative care setting despite the fact that its performance in this population has not been validated. The aim of the study was to determine the sensitivity and specificity of the CAM when used by Non-Consultant Hospital Doctors (NCHDs) working in a specialist palliative care unit. A pilot phase was performed in which NCHDs received a 1-hour training session based on the original CAM training manual. 32 patients underwent 33 assessments in the pilot phase but the sensitivity of the CAM was only 0.5 (0.22-0.78) and specificity was 1.0 (0.81-1.0). An 'enhanced' training programme was devised that took place over two 1-hour sessions and involved case-based learning focused on the areas where the NCHDs were experiencing difficulty. 52 patients underwent 54 assessments in the main phase of the study and the performance of the CAM improved significantly. Sensitivity was 0.88 (0.62-0.98) and specificity was 1.0 (0.88-1.0). The results suggest that the CAM is a valid screening tool for delirium in the palliative care setting but its performance is dependent on the skill of the operator. NCHDs require a certain standard of training before becoming proficient in its use.

Reversibility of delirium in terminally ill patients and predictors of mortality

In this study, factors related to reversibility and mortality in consecutive cases of Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) delirium [n = 121] occurring in palliative care patients were evaluated. Delirium was assessed with the revised Delirium Rating Scale (DRS-R98) and Cognitive Test for Delirium (CTD). Patients were followed until recovery from delirium or death. In all, 33 patients (27%) recovered from delirium before death. Mean time until death was 39.7 +/- 69.8 days in patients with reversible delirium [n = 33] versus 16.8 +/- 10.0 days in those with irreversible delirium [n = 88; P < 0.01]. DRS-R98 and CTD scores were higher in irreversible delirium (P < 0.001) with greater disturbances of sleep, language, long-term memory, attention, vigilance and visuospatial ability. Irreversible delirium was associated with greater disturbance of CTD attention and higher DRS-R98 visuospatial function. Survival time was predicted by CTD score (P < 0.001), age (P = 0.01) and organ failure (P = 0.01). Delirium was not necessarily a harbinger of imminent death. Less reversible delirium involved greater impairment of attention, vigilance and visuospatial function. Survival time is related to age, severity of cognitive impairment and evidence of organ failure.

Successful management of patients with a drug-eluting coronary stent presenting for elective, non-cardiac surgery

This paper describes the management of three patients for elective surgery with drug-eluting stents in the coronary circulation. The risks posed at the time of surgery by such patients include acute coronary syndromes, as a result of stent thrombosis, after cessation of anti-platelet therapy and excessive bleeding from continued anti-platelet therapy. We describe a regime for the management of such patients that successfully avoided these risks in three patients with paclitaxel drug-eluting stents requiring elective non-cardiac surgery.

Evidence for Restricted Vβ Usage in the Leukemic Phase of Cutaneous T Cell Lymphoma

Antibodies directed against the beta chain of the T cell receptor (anti-Vbeta antibodies) are useful to identify the Vbeta repertoire of T cells in various diseases and to quantify numbers of Vbeta-bearing T cells. The goals of this study were to identify Vbeta+ cases of leukemic phase cutaneous T cell lymphoma (CTCL) and to compare the percentage of positive calls with other measures of blood tumor burden, i.e., lymphocyte subsets with a CD4+CD7- and CD4+CD26- phenotype and Sezary cell counts. Thirty-three of 49 (67%) cases of leukemic CTCL reacted with an anti-Vbeta antibody. When combined with reports from the literature, the frequency of Vbeta5 (probably Vbeta5.1) usage was relatively high when compared with Vbeta2 that is also frequently expressed by normal CD4+ T cells. The percentage of Vbeta+ cells correlated to the percentage of CD4+CD7- and CD4+CD26- cells for cases in which the neoplastic cells were deficient in expression of CD7 and CD26, respectively, but not the Sezary cell count. We hypothesize that the increased Vbeta5.1 usage in CTCL may be the result of depletion of Vbeta2 and other Vbeta-bearing T cells by staphylococcal superantigens prior to neoplastic transformation, resulting in a relative increase in the frequency of Vbeta5.1 usage in CTCL.